PROGRAM&
ABSTRACTJapan Prosthodontic Society

BJC_2015.indd 2

15/04/01 13:20

CONTENTS
Welcome Message

1

Joint Congress Organizing Committees
General Information
Access Map
Floor Map

2

3
42015 Biennial Joint Congress of JPS-CPS-KAP Time Table

5

Abstract
Special Lecture

6

Symposium I

7

Symposium II

10

Symposium III

13

Oral Presentations I

16

Oral Presentations II

17

Oral Presentations III

18

Oral Presentations IV

19

Poster Presentations

21

Author Index

34

CORPORATE SPONSORSThe Organizing Committee wishes to thank the following companies for their generous support for the2015 Biennial Joint Congress of Japan Prosthodontic Society, Chinese Prosthodontic Society, andKorean Academy of Prosthodontics.

⃝Sponsors
・3M ESPE・Sun Medical Co., LTD.

⃝Advertisers
・Sun Medical Co., Ltd.
・GC CORPORATION
・Wada Precision Dental Laboratories Co., Ltd.
・J. MORITA CORPORATION
・SHOFU Inc.
・Tokuyama Dental Corporation Inc.
・3M Health Care Ltd.
・KaVo Dental Systems Japan Co., Ltd.
・OSADA ELECTRIC C0., Ltd.

⃝Exhibitor
・Sun Medical Co., Ltd.

Welcome Message

It is a great honor to inform you that the 2015 Biennial Joint Congress of Japan Prosthodontic Society,
the Chinese Prosthodontic Society (CPS), and Korean Academy of Prosthodontics (KAP) will be held in
Hakone from April 10th to 12th, 2015. The main theme of the congress is “Creation, Innovation, andPersonalization.” The program of the congress aims to address comprehensively the principles thatcomprise creative, innovative, and personalized prosthodontics.
Hakone is one of the most beautiful places in Japan and is famous for its hot springs. Nestled along
the world heritage area of Mt. Fuji, the town offer s grand landscapes and beautiful natural surroundings
with an ideal climate.
We cordially invite you to join the congress in beautiful Japan.

Hirofumi Yatani, DDS, PhD
President of the 2015 Biennial Joint Congress of
JPS-CPS-KAP
Joint Congress Organizing Committees

1

Joint Congress Organizing Committees

2
1
3
2

⃝President

4
3
5
4

Hirofumi Yatani Osaka University⃝President
Hirofumi Yatani Osaka University

6
5
7
6

Shoichi Ishigaki Osaka University⃝Secretary
Shoichi Ishigaki Osaka University

8
7
9
8

Misao Kawara
Nihon University⃝Congress
Organizing
Committee

10
9
11
10

Kaoru
Sakurai Tokyo
CollegeMisao Kawara
NihonDental
University
KiyoshiSakurai
Koyano Tokyo
KyushuUniversity
Kaoru
DentalCollege

12
11
13
12

Keiichi Sasaki
University
Kiyoshi
Koyano Tohoku
KyushuUniversity
Takuo
Kuboki
Okayama
University
Keiichi Sasaki Tohoku University

14
13
15
14

KatsumiUoshima
NiigataUniversity
University
Takuo Kuboki
OkayamaTakafumi
Kato
Osaka
University
Katsumi Uoshima Niigata University

16
15
17
16

ChikahiroKato
OhkuboTsurumiUniversity
Takafumi
Osaka
University
Ikuya Watanabe
Chikahiro
OhkuboNagasaki
Tsurumi University
University

18
17
19
18

Takayuki
Ueda Tokyo
DentalCollegeIkuya Watanabe
Nagasaki
University
Hidemasa
ShinpoTsurumiUniversity
Takayuki Ueda Tokyo Dental College

20
19
21
20

Hidemasa Shinpo Tsurumi University

22
21
23
22

⃝Secretary⃝Congress Organizing Committee

1

24
23
25
24
26
25

General Information
Speaker Instruction

Duration of oral presentation are:⃝ 10 min (including 2 min for discussion) for contributed talks
30 min (including 5 min for discussion) for invited talks⃝ Equipment
Oral session room will be equipped with a PC (all computer presentations will be operated by thepresenter), an LCD projector (single projection only), a screen (4 x 3 format), a lapel microphone
and an aisle microphone. Your presentation will be posted on the PC desktop in your assigned
room just prior to your session time. However, you may bring equipment from an outside sourcesuch as a personal laptop.
⃝ PC Rehearsal Desk
All oral presenters must check in at the PC Rehearsal Desk prior to their presentations which is next
to the Registration Desk. Any PowerPoint presenter must bring it, on a USB drive, at least one hourprior to the presentation

Poster Instruction

1.

All posters should be displayed from Friday, April 10 to Sunday, April 12, 2015.
You must set up your poster between 12:00 and 14:30 on Friday, April 10.
You must tear down your poster between 11:20 and 12:50 on Sunday, April 12, 2015.
All poster presenters are required to be at your poster board during the discussion session time
listed below.
10:30 – 11:20 on Saturday, April 11 for the odd-numbered abstracts
10:30 – 11:20 on Sunday, April 12 for the even-numbered abstracts

2.

The poster board will be used VERTICALLY.
The maximum dimensions of the poster should be 180 cm high x 90 cm wide.
The presentation number, the presentation title, author(s), affiliate(s), and the picture of the firstpresenter should be displayed at the top of the poster.

2

Access Map

3

Floor Map

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WC MAPLE OA

BreakfastURA
YAMASAKIMOMIJKIYAMABU

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5th Floor

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FONTAINE BLEAUSKDELOBBY LOUNGE AZALEA

Shuttlebus Stop

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NC
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EV

SHISEN

Baggage Storage
Convention Palace 2nd Floor

to B&B Pension
HakoneWelcome Reception April 10
Gala Dinner April 11
Lunch April 11

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FUJI
（2）

（1）

Dressing Room April 10
Secretariat

Convention Palace 3rd Floor
MOCHIZUKI

Meeting Room
（2）

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（1）

RoomB(Poster)
HORAI

Entrance

RoomA(Oral)
11 April
Lunch

Registration4

2015 Biennial Joint Congress of JPS-CPS-KAP
April 10(Fri), 2015
12:00~
14:00~14:30
14:30~15:10
15:10~15:20
15:20~16:00
16:00~16:30
16:30~17:10
17:10~17:20
17:20~18:00
19:00~21:00

Room A (Hourai)
Registration Open
Opening Ceremony
Oral Session I* Materials
Session Chairperson: Ikuya Watanabe
Speaker 1: Jae-Won Choi Speaker 2: Dong Neong Huh
Speaker 3: Jian Yang Speaker 4: Do-Hyeon Park
Short BreakOral Session II* ImplantSession Chairperson: Ryuji Hosokawa
Speaker 1: Jiawei Wang Speaker 2: Masazumi Yoshitani
Speaker 3: Naoki Kodama Speaker 4: Young-Gun Shin
Coffee BreakOral Session III* Biology
Session Chairperson: Katsumi Uoshima
Speaker 1: Yi Zhou Speaker 2: Makiko Saita
Speaker 3: Withdrawn Speaker 4: Yasuhiko Kawai
Short BreakOral Session IV* Digital dentistry
Session Chairperson: Kazuyoshi Baba
Speaker 1: Jianfeng Ma Speaker 2: Chikayuki Odaira
Speaker 3: Du-Hyeong Lee Speaker 4: So-Hyoun Lee
Welcome Reception (Room Mt. Fuji)

Room B (Mochizuki)
Posters set-up begin

Poster Sessions
Exhibitions

Poster Sessions
Exhibitions*Oral Session: 8 min. presentation followed by 2 min. Discussion

April 11(Sat), 2015

09:00~10:30

10:30~11:20
11:20~12:20
12:20~13:30
13:30~17:30

Room A (Hourai)
Symposium I“Biologic contribution in the prosthodontic research”
Speaker 1: Hiroshi Egusa, Tohoku University,“iPS cells: What they are and what they can contribute to prosthodontics”
Speaker 2: Yongsheng Zhou, Peking University,“What can prosthodontics get from basic research?-PKU experience”
Speaker 3: Jae-Hoon Lee, Yonsei University,“Personalized medicine for dental disease”
Chairpersons: JPS: Takuo Kuboki, CPS: Cui Huang
Coffee Break & Poster Discussion (Odd-Numbered Posters)
Special Lecture
Speaker: Çetin Sevük, Istanbul University, Turkey,“Innovations in single tooth restorations from minimally invasive to implants”
Chairperson: Hirofumi Yatani, Osaka University
Lunch / Executive meeting (Room Wakaba)
Excursion (Hakone & Ashinoko Lake Tour, Optional)

Room B (Mochizuki)

Poster Sessions
Exhibitions

Poster Sessions
Exhibitions

Poster Sessions
Exhibitions

Gala Dinner (Room Mt. Fuji)

19:00~21:00

April 12(Sun), 2015

09:00~10:30

10:30~11:20

11:20~12:50

12:50~13:00

Room A (Hourai)
Symposium II“The cutting edge of prosthodontic practice”
Speaker 1: Osamu Komiyama, Nihon University Matsudo Dental School,“The importance of brain function and force control in prosthodontic treatment”
Speaker 2: Haiyang Yu, Sichuan University, “DLD, a digital approach to dental esthetic design”
Speaker 3: Hyeong-Seob Kim, Kyung Hee University,“Current trends about zirconia restorations in Korea”
Chairpersons: CPS: Yining Wang, KAP: Jung-suk Han
Coffee Break & Poster Discussion (Even-Numbered Posters)
Symposium III“Implant prosthodontics”
Speaker 1: Yasunori Ayukawa, Kyusyu University,“The acquisition of secure peri-implant soft tissue sealing”
Speaker 2: Xinquan Jiang, Shanghai Jiao Tong University,“Application of structure and chemical cues in biomaterials design to promote osseointegration”
Speaker 3: Seong-Joo Heo, Seoul National University,“Clinical application of biomechanical researches in implant dentistry”
Chairpersons: JPS: Kiyoshi Koyano, KAP: Dong-Hoo Han
Award, Closing Ceremony

5

Room B (Mochizuki)

Poster Sessions
Exhibitions

Poster Sessions
Exhibitions

Special Lecture
April 11 (Sat), 2015 Room A (Hourai) 11:20~12:20
Chairperson: Hirofumi Yatani (Osaka University)

Innovations in single tooth restorations fromminimally invasive to implants
Prof. Dr. Çetin Sevük
Istanbul University

Abstract
Various restorations are applied in order to replace damaged and extracted teeth. In these situations
the aim is to preserve the remaining tooth structure and replace the missing tooth without damaging theadjacent teeth. In other words, a minimally invasive approach should be taken when planning and applying the restorations.
For the restoration of the teeth with excessive material loss, conventional procedures are replacedwith new materials matching the shade of the tooth and resistant to functional loads. This is made possible with inlays and endocrowns which are compatible with the remaining tooth structure.
In the single tooth loss cases, conventional bridge restorations are preferred less and procedures
such as adhesive bridges and implants are applied instead. For this reason, custom implant procedures are getting popular in addition to contemporary implant applications.

Brief CVProf Dr. Çetin Sevük was born in 1949. He graduated from Istanbul University, Faculty of Dentistry in 1974. Hecompleted his post-graduate course and obtained his PhD degree in the Department of Fixed Prosthodontics
at the same university in 1979. He was promoted to associate professor in 1988, and professor in 1996. Prof Dr.
Çetin Sevük is the president of the Turkish Society of Prosthodontics and Implantology (TPID), board member ofEuropean Prosthodontic Association (EPA), Immediate Past president of EPA and also an active member ofComputer Aided Implantology Academy (CAIA). Presently he continues teaching at the Department of Fixed
Prosthodontics, in İstanbul University, Faculty of Dentistry. He has numerous researches about all ceramic restorations and inlay restorations.

6Symposium I“Biologic contribution in the prosthodontic research”

April 11 (Sat), 2015 Room A (Hourai) 9:00~10:30
Chairpersons: Takuo Kuboki (JPS), Cui Huang (CPS)iPS cells: What they are and what they doin the future of prosthodontics
Prof. Hiroshi Egusa
Tohoku University Graduate School of Dentistry

Abstract
Induced pluripotent stem (iPS) cells can be generated through the reprogramming of somatic cells
from different tissues by forced expression of defined exogenous factors. These iPS cells efficiently
generated from accessible tissues have the potential to be used for various clinical applications. The
oral gingiva is an easily obtainable tissue for dentists, and cells can be isolated from patients with minimal discomfort. We successfully generated iPS cells from adult mouse or human gingival fibroblasts
via transduction of the Yamanaka factors without c-Myc oncogene. Gingival fibroblasts demonstrate ahigher reprogramming efficiency than the skin fibroblasts which have been conventionally used for thegeneration of iPS cells. These iPS cells were capable of osteogenic differentiation, which could form
new bone in the animal models. The generation of iPS cells from the gingiva is expected to provide abreakthrough, especially in the dental sciences, because it offers a promising method for the facile
production of pluripotent stem cells by dental researchers. In this presentation, generation and basic
aspects of osteogenic capacity of the gingiva-derived iPS cells will be discussed, with an emphasis on
potential applications of the iPS cell technologies in the future of prosthodontics.

Brief CV
1998: Hiroshima University Faculty of Dentistry (DDS)
1999: Technical Assistant, Faculty of Dentistry, Dept. of Oral Biology, University of Hong Kong
2002: Hiroshima University, Graduate School of Dentistry (PhD)
2002-2004: Postdoctoral Research Fellow, Japan Society for the Promotion of Science
2002-2004: Postdoctoral Research Fellow, Weintraub Center for Reconstructive Biotechnology, UCLA Schoolof Dentistry2004-2014: Assistant Professor, Chief of Biology-Driven Prosthodontics Research Group, Osaka University
Graduate School of Dentistry2014-present: P rofessor and Chair, Division of Molecular and Regenerative Prosthodontics,
Tohoku University Graduate School of Dentistry7Symposium I
April 11 (Sat), 2015 Room A (Hourai) 9:00~10:30

What can prosthodontics get frombasic research?-PKU experience
Prof. Yongsheng Zhou
Peking University, School and Hospital of Stomatology

Abstract
Through long-term efforts, we have come a long way in bone tissue engineering or bone regeneration
which shows great prospects for oral maxillofacial rehabilitation and implant dentistry in the future. However, biological safety, efficiency, feasibility, cost-effectiveness, etc are still the main factors that determine its wide usage in clinical translation. In order to overcome these difficulties, we have developed
some new concepts and new approaches in bone tissue engineering based on human adipose-derived
stem cells (hASCs) and cell-homing strategies. We firstly constructed tissue-engineered bone based on
hASCs, human Platelet-Rich Plasma, and simvastatin which facilitates the future clinical translation because all the components are easily available. Further, we investigated the potential value of using primary hASCs, non-osteoinduced hASCs in bone tissue engineering and found that primary hASCs or
non-osteoinduced hASCs could be used directly in the construction of a tissue-engineering bone. We
also examined if we could use small chemical molecules to enhance the osteogenic differentiation of
hASCs and found that pargyline and CCB1007 could be used to enhance the osteogenic differentiationof hASCs. Next, a cell homing strategy which eliminated the seed-cell implantation was also introduced
in my study. We constructed a novel cell-free bone tissue engineering system using PLGA loaded with
SIM and SDF-1a, and applied it in critical-sized calvarial defects in mice. At the same time, the underlying mechanisms such as epigenetic and molecular factors that govern the efficiency, feasibility, andbiological safety of bone tissue engineering or bone regeneration were fully investigated. These preliminary explorations will facilitate development of new approaches for treatment of oral maxillofacial defects or bone shortage in implant therapy in the coming era.

Brief CV
Dr. Yongsheng Zhou is the Professor and Chair of Department of Prosthodontics, Peking University School of
Stomatology (PKUSS). He achieved his DDS degree in PKUSS in 1994 and PhD in the same school in 1998. He
accepted postdoctoral training in University of North Carolina Dental Research Center, Department of Prosthodontics for one year. Dr. Zhou is currently a Diplomate of the Chinese Prosthodontic Society. He is the vice-president of Chinese Society for Oral Maxillofacial Rehabilitation, a standing Committee member of Chinese Prosthodontic Society, Council member of Asian Academy of Prosthodontics, and commissioners of Beijing Municipal
Stomatological Association, and National Board of Dental Examiners, etc. He is also a member of Education andResearch Committee of International College of Prosthodontists. He is an editor for 6 academic journals in
Stomatology. His Researches focus on the usage of bone tissue engineering based on adult stem cells to restore oral bone loss, material surface modification for improving osteogenesis, and digital technology, etc.

8Symposium I
April 11 (Sat), 2015 Room A (Hourai) 9:00~10:30

Personalized medicine for dental disease
Prof. Jae-Hoon Lee
Yonsei University

Abstract
Genetic information is stored in the form of DNA and has a direct impact on the characteristics of individual and his or her susceptibility to specific disease. Early diagnosis of specific disease using genetic variants as the marker is very advantageous, because of its low variability, high repetition rate andhigh stability between generations, which allows effective analysis of genes. Currently, with the completion of human genome project, study of genetic association of disease using NGS, an innovative method to sequence genome is being widely used to find indicators for diseases. However, despite thisadvancement in medicine, the study and clinical application of this approach is lacking in dentistry andis limited to the study of rare dental developmental disorders. This presentation will address how
multi-genic dental disorder is screened with whole exom sequencing and further analyze with bioinformatics including protein networks and variant enrichment analysis. Through this study the genes thatplay important role in the pathogenesis of the dental disease has been identified and it can be used asa biomarker to find individuals who are susceptible to specific disease. This finding will enable dentist
to make early diagnosis and prevention plan in dental disease and eventually, it will bring dentistry a one
step closer to personalized medicine.

Brief CV
1994: BS Agricultural Biology at Korea University, Seoul
1999: DDS School of Oral and Dental Surgery at Columbia University, New York
2000: GPR residency Montefiore Hospital, at Bronx, New York
2003: MS Post Graduate Prosthodontics at Columbia University, New York
2003: Pre-clinic instructor: Fixed prosthodontics at Columbia University
2006: Lecturer: Fixed prosthodontics course at Yonsei University
2008: Ph.D Graduate School of Dentistry at Yonsei University, Seoul
2008: Course director: Fixed prosthodontics course at Yonsei University
2010: Visiting scholar Weintraub laboratory at University of California at Los Angeles
2012: S enior-student clinic instructor and secretary at clinical education committee at
Yonsei University9Symposium II“The cutting edge of prosthodontic practice”

April 12 (Sun), 2015 Room A (Hourai) 9:00~10:30
Chairpersons: Yining Wang (CPS), Jung-suk Han (KAP)

The importance of brain function andforce control in prosthodontic treatment
Prof. Osamu Komiyama
Nihon University Matsudo Dental School

Abstract
Various esthetic prosthodontic treatments including dental implants are more prosperous than everwith the evolution of dental technology. However, there is general agreement that excessive stress to theprosthesis may result in overload of the human tissue and physical failure of the prosthodontic structure.
Many clinicians believe that overload of a dental prosthesis is a risk factor for bone loss and/or may be
detrimental for the suprastructure in implant prostheses. It has been documented that occlusal parafunction such as bruxism (tooth grinding and clenching) affects the outcome of prostheses, and thoseparafunctions are initiated in the central nervous system. During occlusal examination of the patient, theocclusal contact area and the bite force of a patient provide valuable information for prosthodontic
treatment and its prognosis.
In a previous paper on the central nervous system, we clarified that the masticatory inhibitory reflex,
as a brainstem reflex to interrupt tooth clenching, has a wide variety of appearance threshold individually following stimuli with increasing intensity. We also demonstrated that repeated and standardized
tooth clenching tasks triggered significant neuroplastic changes in the corticomotor control of jaw-closing muscles but not of a hand muscle. On the other hand, in previous papers regarding the peripheral
masticatory system, we showed that the occlusal contact areas increased with increasing tooth clenching intensity which may affect the tooth and the periodontal tissues, and that an adequate narrative instruction may contribute to taking a stable occlusal recording in natural dentition.
In this lecture, the importance of brain functions and force control in prosthodontic treatment will be
discussed to prevent the failure of esthetic prosthodontic treatment.

Brief CV
Osamu Komiyama received the degree in Doctor of Dental Science from the Nihon University, Japan, in 1989,
and served as an instructor at the Department of Complete Denture Prosthodontics. After that, he obtained a
Ph.D. degree in Dental Science from the Nihon University in 1998. He served as an assistant professor at the
Department of Comprehensive Clinical Dentistry, School of Dentistry at Matsudo, Nihon University in 2002, andwas a visiting Professor at Catholic University of Leuven from 2003 to 2005 as host Professor Antoon De Laat in
Belgium. He is currently an Associate Professor at the Department of Oral Function and Rehabilitation, Nihon
University, and the President of a Neuroscience Group of the International Association for Dental Research. His
research interests include the development of new somatosensory functional evaluation method in the trigeminal region, clinical neurophysiological evaluation of masticatory function, experimental characterization of orofacial pain patients, and the relation among brain functions, jaw movement, and force control with prosthodontic
treatment.

10Symposium II
April 12 (Sun), 2015 Room A (Hourai) 9:00~10:30

DLD, a digital approach todental esthetic design
Prof. Haiyang Yu
Sichuan University

Abstract
The esthetic restoration workflow should includes two steps, dental esthetic design and the clinicaltreatment. In the first stage, the dentist and the technician make design and treatment plans. Face, lip,
gingiva and tooth shape and color should be taken into consideration. It’s a creative step. In the second
stage, with special transfer techniques, esthetic restorations are finished exactly according to the esthetic design. The key points are esthetic design and esthetic preview. We develop final target basedon the different esthetic factors of patients and demonstrate the esthetic effect to dentists, technicians
and patients through digital design, wax-up and diagnostic resin veneers, which is helpful to feedback
and modification of esthetic effects. In clinical treatment, gingiva tissue, tooth preparation, and restoration fabrication should accord with our esthetic goal. In case need change shape of gingiva curve. We
made a wax-up to preview the ideal gingiva level. Then make a transparent index. It provided a clear
mark in patient’s mouth. According to this marker, the periodontal surgery can be carried out in a controlled way. We usually make depth-orientation grooves to control preparation. But in many esthetic
cases, we need change the shape of tooth. Depth-orientation grooves is no longer appropriate in this
scenario. Instead, we use silicon index. You can make a impression from wax-up, put it into patient’s
mouth. It will helps to reveal the exact amount of tooth structure you need.

Brief CV
Dr. Haiyang Yu earned his Bachelor of Medicine degree in 1992 and his Doctor of Medicine degree in 1997
from West China College of Stomatology. He is currently Research Dean and Chair Professor of the Departmentof Prosthodontics at West China Hospital (college) of Stomatology, Sichuan University.
Dr. Haying Yu is the secretary general of The Guiding Committee of Higher Dental Education, Chinese Ministry Education. He is assistant editor of the Bone Research and subeditor of West China Journal of Stomatology.
Dr. Haiyang Yu is involved in both clinical and research works. As the conductor, he in charge of the State Key
Clinical Department of Prosthodontics and the Distinctive Clinic of Implant Rehabilitation. He is expert in Dental
ceramic aesthetic rehabilitation, aesthetic removable denture and complex implant rehabilitation. On the basisof his working experience, he put forward several aesthetic rehabilitation theories, such as the line-plane relationship analysis and design principle, esthetic preview and transfer guidance technic, and so on. Those theories and technics have been written down and published.

11Symposium II
April 12 (Sun), 2015 Room A (Hourai) 9:00~10:30

Current trends about zirconia
restorations in Korea
Prof. Hyeong-Seob Kim
Kyung Hee University

Abstract
Zirconia is one of the most promising restorative biomaterial, because it has very favorable mechanical and chemical properties suitable for medical application. Zirconia based restorations are widelyused in Korea such as single crown, fixed partial denture and implant abutment. Y-TZP has the potential
for being accepted as a suitable material for fixed prosthodontic dental treatment; however there are a
few clinical trials with large sample sizes and longer follow-up periods. The most common complication
observed in zirconia based restorations is chipping fractures and delamination of the veneering ceramic. Numerous reasons have been suggested such as mismatch of CTE between the zirconia core andveneering porcelain, mechanically defective micro-structural regions in the porcelain, surface defects
or improper support by the framework, overloading, low fracture toughness of the veneering porcelain
and the low thermal conductivity of zirconia.
In these days paradigm about zirconia restorations is shifted to full-contour monolithic zirconia restorations. The development of full-contour monolithic zirconia crowns promises an end to the heartbreakof fractured esthetic porcelain on posterior crowns and bridges.
I will present current status about zirconia restorations in Korea and discuss about the key factors for
successful zirconia restorations.

Brief CV
1988-1994: DMD, Dental College, Kyung Hee University
1994-1998: Internship & Resident, Department of Prosthodontics, Dental Hospital, Kyung Hee University
1998-2000: Clinical Instructor, Department of Prosthodontics, Dental Hospital, Kyung Hee University
2000-2003: Assistant professor, Department of Dentistry, Medical School, Ewha Women’s University
2003-2004: Clinical Assistant Professor, Department of Prosthodontics, Dental Hospital, Kyung Hee University
2004-2007: Assistant Professor, Department of Prosthodontics, Dental College, Kyung Hee University
2008-2008: Visiting Professor, Department of Prosthodontics, Tuebingen University, Germany
2008-2012.8: Associate Professor, Department of Prosthodontics, School of Dentistry, Kyung Hee University
2012.9-present: P rofessor and chair, Department of Prosthodontics, Dental Hospital, Kyung Hee University
Director of education, training & accreditation, Korean Academy of Prosthodontics

12Symposium III“Implant Prosthodontics”DLD, a Digital

April 12 (Sun), 2015 Room A (Hourai) 11:20~12:50
Chairpersons: Kiyoshi Koyano (JPS), Dong-Hoo Han (KAP)

The acquisition of secure peri-implant
soft tissue sealing
Prof. Yasunori Ayukawa
Kyushu University

Abstract
Although peri-implant soft tissue stability is supposed to be equally important to osseointegrationfrom the viewpoint of dental implants with sustainable function, the intervention to this field is relatively
insufficient. Especially, while multidisciplinary approaches to the treatment for peri-implantitis are done,
the evolution of the material to prevent peri-implant soft tissue disease is eagerly anticipated.
In our previous study, hydrothermal treatment of titanium with CaCl2 solution strongly enhances theosseointegration without any predominant surface alterations. The reason for this enhancement is aconsequence of the presence of calcium at the titanium surface. Calcium may enhance the adsorptionof Ca-binding proteins such as osteocalcin or osteopontin, which are known to be a substratum for osteoblasts.

In the next work, we investigated the possibility of this treatment for the enhancement ofperi-implant soft tissue sealing. In our in vitro study, Ca-hydrothermal treatment strongly enhanced thecell attachment durability against the detachment force of both fibroblast and oral epithelial-like cells.
Western blotting and immunofluorescence microscopy indicated the development of well-organizedadhesion structure-related proteins. In vivo rodent oral implant study indicated that Ca-hydrothermal
treated titanium represented secure epithelial attachment with laminin-332-rich adhesive structure,
which was almost identical to that between epithelial cells and enamel of the tooth. In addition, barrier
property against foreign body penetration into tissue was greater than that of untreated titanium implant
and this characteristic sustained for a relatively longer period.
Ca-hydrothermal treatment can be easily applied to titanium, without special devices and minimal
surface topographical alteration and our results suggested the possibility for the enhancement of bothosseointegration and peri-implant soft tissue sealing.

Brief CV
1993: DDS, School of Dentistry, Kyushu University, Fukuoka, Japan
1997: PhD, Graduate School of Dental Science, Kyushu University
1997: Resident, Kyushu University Dental Hospital (2nd Department of Prosthodontics)
1998: Assistant Professor, Kyushu University Faculty of Dentistry (Section of Reconstructive Biotechnology)
2004-present: Lecturer, Kyushu University Hospital (Section of Implant and Rehabilitative Dentistry)
2012: Visiting assistant professor, University of Iowa, IA, USA (Dows Institute for Dental Research)

13Symposium III
April 12 (Sun), 2015 Room A (Hourai) 11:20~12:50

Application of structure and chemical cues inbiomaterials design to promote osseointegration
Prof. Xinquan Jiang
Shanghai Jiao Tong University
Department of Prosthodontics

Abstract
Bone tissue engineering is an emerging interdisciplinary field that applies the principles of biology
and engineering to the development of viable tissue substitutes that restore and maintain the function ofhuman bone. There are many approaches used for bone tissue engineering and all involve one or moreof the following key components: seeded cells, growth factors and three-dimensional (3D) biomaterial
scaffolds. Adult stem cells, which show promise for bone tissue engineering, have been derived frombone marrow, periosteum, adipose tissue, skeletal muscle, skin, and other sources. And the adult stem
cells have been identified from specialized tissues in the craniomaxillofacial region, including dental
pulp and periodontal ligament, which may offer advantages for craniomaxillofacial bone regeneration.
Bone tissue is composed of a heterogeneous mixture of cell types embedded in mineralized extracellular matrix (ECM) within a 3D structure. The ECM is a particularly rich source of signaling molecules, acts
as a structural support, as a reservoir of growth factors, a transducer of mechanical signals, a source of
spatial cues delivered via chemical epitopes, and many related features. Biomaterial scaffolds play a
critical role in bridging the gap between the developmental context of bone tissue engineering and thediverse context of bone regeneration in terms of clinical needs. Strategies for designing new biomimetic scaffolds which account for the hierarchical organization of natural bone have been investigated.
Such scaffold properties, including biomaterial biocompatibility, chemical composition, geometry, porosity, mechanical strength, and degradation rate can be optimized to address the physiological requirements of tissue-engineered bone. More importantly, the design of hybrid micro/nanoscale structures and bioactive trace elements into biomaterials would be a novel strategy to enhance boneregeneration and osseointegration.

Brief CV
Professor Xinquan Jiang is currently the Director of the Department of Prosthodontics, in School of Stomatology, Shanghai Jiao Tong University, China, and the Director of Shanghai Engineering and Research Center in
Universities for Advanced Dental Technology and Materials. He is also an honorary professor in Faculty of Engineering and IT, the University of Sydney, Australia.
He received his PhD in 2003 at Shanghai Second Medical University and completed exchange studies at the
University of Alberta in Canada and received a visiting scholarship at the School of Dentistry, University of California, Los Angeles (UCLA), in the United States. He serves as the fellow of ICD (international college of dentistry), member of ICP (International College of Prosthodontics) standing committee, regional representative for
the Asian Academy of Prosthodontics (AAP), vice president of Chinese Prosthodontic Society.

14Symposium III
April 12 (Sun), 2015 Room A (Hourai) 11:20~12:50

Clinical application of biomechanical researches in
implant dentistryProf. Seong-Joo Heo
Seoul National University

Abstract
Dentists and researchers have debated the identification and application of concepts of biomechanical researches to dental implant treatment for many years. There are many biomechanical factors whichshould be considered during implant treatments. Following factors will be discussed during the presentation.
1. Occlusal material for temporary restoration and final restoration
2. Type of Occlusion: Canine guidance, group function, Bilateral balanced
3. Occlusal contact height: hypo-occlusion, equal occlusiont
4. Hypo-occlusion due to sinking down of internal connection type implants
Among above factors, occlusal contact height looks very important effects on prognoses of implants
and adjacent natural teeth. The concept of light contact during heavy biting and no occlusal contact
during light biting was recommended by Lundgren and Laurell and Kim et al. However, some authors
have reported that hypo-occlusion of dental implants may cause occlusal disharmony, with adjacent
teeth receiving most of the occlusal force, and they suggested equal occlusion for implant crowns andany remaining natural teeth. The our opinion and experiences on occlusal height will be addressed.
Finally the most difficult and challenging cases will be discussed. The cases of implant supported
RPD cases and increasing of vertical dimension using implants as key abutments will be also discussed.

Brief CV

1977-1983:
D.D.S., Seoul National University, School of Dentistry
1987-1989:
Specialty in prosthodontics, M.S. in Oral Science		State University of New York at Buffalo
1994-present Professor, Seoul National University, School of Dentistry
1996-1997:
Visiting Professor, Goteborg University, Sweden
2004-2007:
Chairman, Department of Prosthodontics, Seoul National University
2010-2014:
Director, Department of clinical affairs, SNU Dental Hospital
2002-present: International Journal of Prosthodontics, Reviewer
2013-present: President Elect, Korean Academy of Prosthodontics
2011-present: President, Korean Academy of Oral and Maxillofacial Implantology
2007-present: Vice president, Korean Biomaterial Society
2014-present: Co-Chair of Scientific Program, ICP 2015 Meeting at Seoul

15

Oral Presentations

April 10 (Fri), 2015 Room A (Hourai)

Oral Session I Materials
14:30~15:10
Chairperson: Ikuya Watanabe (JPS)

clearance was adjusted. Finally, the final prosthesis was made anddelivered.
If successful, surgical replantation has advantages over implant
treatment since the natural teeth keeps the periodontal ligament. The
method may be considered first especially in cases with fractured anterior teeth since it is considered to show better esthetic prognosis.

I-1
Comparison of changes in retentive forceof three stud attachments

I-3

Jae-Won Choi, Su-Min Kim, Young-Chan Jeon,
Chang-Mo Jeong, Mi-Jeong Yun, Jung-Bo Huh

Full-month rehabilitation of erosion
dentition utilizing chairside CAD/CAM
occlusal veneers

Department of Prosthodontics, Busan National University,
School of Dentistry

Jian Yang, Yongsheng Zhou

The aim of this study was to compare the changes in retentive forceof stud attachments for implant overdentures by in vitro 2-year-wear
simulation.
Three commercially available attachment systems were investigated: Kerator blue, O-ring red and EZ lock. Two implant fixtures wereembedded in parallel in each custom base mounting. Five pairs ofeach attachment system were tested. A universal testing machine wasused to measure the retentive force during 2500 insertion and removal
cycles. Surface changes on the components were evaluated by scanning electron microscopy (SEM). A Kruskal-Wallis test, followed by
Pairwise comparison, was used to compare the retentive force between the groups, and to determine groups that were significantly different (P<.05).
A comparison of the initial retentive force revealed the highest value
for Kerator, followed by O-ring and EZ lock attachments. However, nosignificant difference was detected between Kerator and O-ring(P>.05). After 2500 insertion and removal cycles, the highest retention
loss was recorded for O-ring, and no significant difference between
Kerator and EZ lock (P>.05). Also, Kerator showed the highest retentive force followed by EZ lock and O-ring, after the 2500th cycle(P<.05). Based on SEM analysis, the polymeric components in O-ringand Kerator were observed to exhibit surface wear and deformation.
After 2500 insertion and removal cycles, all attachments exhibited
significant loss in retention. Mechanism of retention loss can only bepartially explained by surface changes.

Department of Prosthodontics, Peking University, School and
Hospital of Stomatology, Beijing 100081, China
Dental erosion, defined as a progressive loss of dental hard tissue
as a result of chemical process without bacteria involved. Several reports have proposed to use of minimally invasive procedures to treatsuch patient in stead of traditional full-crown rehabilitation. the use oflithium disilicate occlusal venners, in combine with improvement indental adhesion, allow a more conservative approach. A 36 years oldmale with erosion dentition. Extraoral examination revealed lightly reduced VDO ,Intraoral examination reveals extreme wear of lingual surface of maxillary anterior teeth and occlusal surfaces of most posterior
teeth in the patient’s mouth ,and incisor margin of the anterior teeth issharp and become shorter. After space analysis and esthetic evaluation, direct resin composite technique was chosed to restore lower anterior teeth and 2 mandibular premolar, where the tooth wear is notseverely. Chairside CAD/CAM technique and lithium disilicate partial
coverage veneers were utilized to restore the rest posterior tooth andcanine with severly tooth wear, 4 full coverage lithium disilicate veneers
were utilized to restore the esthetics of maxillary incisors and anterior
guidance. This report combined Chairside CAD/CAM technique andminimal invasive adhesive rehabilitation in the treatment plan for a patient with erosiion dentition.

Keywords: Overdenture attachment, Resilient attachment, Retentive
force, Surface wear

I-4
Effect of activation modes on compressive
strength and diametral tensile strength ofdual cured self-adhesive resin cements

I-2
Treatment of fractured maxillary
central incisors using surgical replantation

Do-Hyeon Park, Ah-Rang Kim, Young-Chan Jeon,
Chang-Mo Jeong, Mi-Jeong Yun, Jung-Bo Huh

Dong Neong Huh, Seong Jae Park
ItPlant Dental Clinic

Department of Prosthodontics, Busan National University,
School of Dentistry

Surgical replantation has been used to have longer clinical crownlength especially when teeth are fractured. One of the most common
cases is the fracture of the central incisor. When this happens, the palatal side of the crown tends to be severely damaged leading to the lossof the supragingival part of the side. While forced eruption followed byclinical crown lengthening procedure is widely used, surgical replantation may also be a good treatment option. Although implant treatment
is commonly used recently, keeping the natural teeth may be considered first, if possible.
In this case report, the patient had his two maxillary central incisor
fractured. Surgical replantation with rotation was performed followedby re-endodontic treatment. Since the occlusal clearance was quite
tight, adjustment of the occluding dentition was also carried out.
Fiber posts were inserted and cores were built. Provisional prosthesis was made and delivered. During the provisional period, occlusal

Purpose: The purpose of this study was to compare the compressive strength and diametral tensile strength of several dual-cured
self-adhesive resin cements by different activation modes and testingtime.
Materials and Methods: Six dual-cured self-adhesive resin cements
currently used (Rely-X U200, Clearfill SA Luting, G-CEM LinkAce, Maxcem Elite, PermaCem 2.0 and Zirconite) were included for this study.
Cylindrical specimens were prepared for compressive strength test (Ø4 x 6 mm) and for diametral tensile strength test (Ø 6 x 3 mm) according to ISO standard. Each cement divided into six groups in combination with two activation modes (self-cure in water at 37℃, 40 seconds
light-cure) and three testing time (immediately, 24 hours after curing,after 2,000 thermal cycles). Both tests were conducted using an universal testing machine according to ISO standard. The data were statistically analyzed using t-test, one-way ANOVA, two-way ANOVA and

16

Oral Presentations

the multiple comparison Scheff's test (P<.05).
Results: Compressive strengths and diametral tensile strengths ofdual-cured self-adhesive resin cements showed variable results from
142.94 MPa to 298.14 MPa and from 22.76 MPa to 44.48 MPa respectively. In the comparison between testing times, the compressive
strength and diametral tensile strength after 24 hours were higher than
immediate testing. In the comparison between cements, G-CEM
showed the highest values compared to other cements except diametral tensile strength immediatly. In the comparision between activation
modes, Rely-X U200, PermaCem 2.0 and Zirconite had higher values
in light-curing than self-curing activation mode, while another cements
revealed no statistically significant differences according to activation
modes.
Conclusion: Self-adhesive resin cements revealed differences incompressive strength and diametral tensile strength according to theircomposition, testing time, activation mode. All cements demonstrated
clinically available strength values. This results may be used as theguide line for selecting of resin cements.

Functional Science, Graduate School of Dental Medicine,
Hokkaido University
Purpose: The aim of this study was to investigate the effects of implant numbers on the distribution of occlusal force in the unilateral defect of the molar region of mandible.
Methods: We constructed three-dimensional finite element models
of a mandible with left second molar missing (MT7), left molars missing(MT67), one or two implant(s) placed on MT67 (Im6, Im67). Linear elastic and isotropic material properties were defined for all elements except for the periodontal ligament with biphasic elasticity. The load wasassumed intercuspal clenching and generated by the contractile forceof masticatory muscles. The amount of the load was defined according
to total occlusal force on the occlusal surfaces (200N, 400N, and800N). Displacement was restricted through nonlinear springs with appropriate biphasic elasticity at temporomandibular joints, central fossa
or incisal edge of teeth and superstructures. The elasticity of thesprings on the teeth and the implants simulated opposing natural teeth
at compression. The springs on the superstructures also had quite
small elasticity at low compression to allow some upward movement,
which was determined by a trial-and-error method so that symmetric
distribution of the occlusal force was observed under load 400N, withslight resistance.
Results: The ratio of the occlusal force on the superstructures increased under larger load. The force distribution in Im67 was almost
similar to natural dentition. The occlusal force on the second premolar
was 2.3−3.8 and 1.9-2.5 times greater than that of opposite side in MT7
and Im6, respectively. The force distribution of Im6 was almost similar
to that of MT7.
Conclusion: From the viewpoint of occlusal force distribution, two
implants placement is recommended for the unilateral defect of themolar region of mandibles. The occlusal force distribution with one implant placement was similar to that of second molar missing model.

Oral Session II Implant

15:20~16:00
Chairperson: Ryuji Hosokawa (JPS)

II-1
Esthetic restoration of anterior
hypodontia with oral implant
Jiawei Wang, Yining Wang, Yi Zhou
Wuhan University
Congenital tooth missing is one of the most common dental anomalies, which is associated with anomalies during the formation process
and the early development of tooth germ. According to the number ofmissing teeth, congenital tooth missing can be divided into hypodontia(less than 6 teeth), oligodontia (more than 6 teeth), and anodontia(missing all teeth). The most common tooth agenesis is the third molar,
which accounts for 20% of missing teeth, and then is the second premolar, the upper lateral incisor, and the lower anterior tooth. The toothmissing will induce a lots of symptoms in the clinic, such as diastema,
midline unalignment, anomaly of overbite and overjet, anomaly of occlusion, deciduous tooth retention, decrease of lower facial 1/3 height,
retraction of jaw, tooth transposition, and etc. Although the incidence ofanterior hypodontia is low, it heavily influences the patient’s countenance and pronunciation. Esthetic restoration of anterior hypodontia
with oral implant should take a multidisciplinary approach, which combines the benefits of orthodontic, periodontic, and prosthodontic treatment. Firstly, orthodontic treatment is applied to the patients with aim toadjust the space, correct midline, improve occlusion, and align dentition. After that, the surgeon should pay attention to several characteristics of anterior hypodontia, i.e. deficient horizontal bone volume, excessive vertical bone volume, small missing space, and lower gingival
curve of adjacent teeth. The strategies to solve these questions areproposed, which includes GBR, bone trimming, small diameter implant, and crown lengthening. The final restoration is finished by theprosthodontist with the aid of precision impression technique, zirconia
abutment and all ceramic crowns. Several typical cases are presented
to demonstrate the above mentioned issues at the same time.

II-3
The impact of implant-assisted overdenture
on nutritional status: A meta-analysis
Naoki Kodama1,2, Shogo Minagi1, Elham Emami2
1

Department of Occlusal and Oral Functional Rehabilitation,
Okayama Univesity Graduate School of Medicine,
Dentistry and Pharmaceutical Sciences2
Departement of Restorative Dentistry, Faculty of Dentistry,
Université de Montréal

Objective: The aim of this meta-analysis was to quantitatively summarize the evidence for the impact of implant-assisted overdenture on
nutritional status of edentate individuals.
Methods: Eligible studies were identified by searching electronic
databases including Medline, Embase, The Cochrane Central Register of Controlled Trials, and The Cochrane Systematic Reviews Database (via Ovid) for the period up to October 2014. The eligible studies
included randomized-controlled trials in which conventional denturesand mandibular implant overdentures in adult edentate individuals
were compared in regard to the outcome of interest. This included nutritional status, and its related indicators such as body mass index,
macronutrients and micronutrients. Random effects models were used
to pool the effect sizes (ES) of all included studies.
Results: In total, 1,596 non-duplicate articles were identified fromdatabase searches. Six publications of six randomized-controlled trials
were identified and four were included in the meta-analysis. There wasno statistically significant difference in the 14 indicators of nutritional
status of edentate individuals wearing implant-assisted overdenture
when compared to those wearing conventional denture. The pooled ES
for Albumin was -0.37 (Z=1.10, 95% confidence intervals -1.03 to 0.29;
p=0.27, Chi2=0.21, df=2, p=0.90, I2=0%) revealing non significant
small effect size in favour of the conventional denture treatment.

II-2
Effects of implant numbers on
occlusal force distribution
Masazumi Yoshitani, Yoshiyuki Takayama, Atsuro Yokoyama
Department of Oral Functional Prosthodontics, Division of Oral

17

Oral Presentations

marrow MSCs. Effects of LIF were investigated in a model of ischemia
consisting of hypoxia and serum deprivation in vitro.
Results: Apoptosis of MSCs was induced by exposure of cells tohypoxia and serum deprivation. Data showed that the protective effectof LIF on MSCs was dose-dependent and peaked at 40ng/ml. Further
study revealed that LIF could inhibit the loss of mitochondrial membrane potential, reduce the activation of caspase-3 and decrease theexpression of Bim and Bax/Bcl-2 ratio. In addition, LIF induced janus
kinase 1 (JAK1) and signal transducer and activator of transcription 3(STAT3) phosphorylation. The anti-apoptotic effect of LIF could becompletely blocked by the JAK1 and STAT3 specific inhibitors.
Conclusion: These results demonstrate that LIF can protect MSCs
against hypoxia and serum deprivation-induced apoptosis via JAK1/
STAT3 pathway. It implies that LIF may be a promising agent for improving MSCs survival during cell transplantation.

Conclusion: These findings suggest that there is no evidence of nutritional differences between edentate individuals wearing implant-assisted mandibular overdentures and those wearing conventional complete dentures. Large nutritional epidemiology studies, with long-term
follow-up are needed to improve our understanding of the impact of
implant overdenture on nutrition.

II-4
Influence of double locking abutment on
implant-abutment screw joint stability
Young-Gun Shin, Young-Chan Jeon, Chang-Mo Jeong,
Mi-Jeong Yun, Jung-Bo Huh

III-2

Department of Prosthodontics, Busan National University,
School of Dentistry

Metabolome analysis of saliva on
occlusal and masticatory stimulations

The purpose of this study was to examine the effect of the Influenceof double locking abutment on Implant-abutment screw joint stability.
In this study, 20 internal hex type fixture, 10 single screw abutment and
10 double locking abutment were used.
The implant fixture was fixed to the separately manufactured jig, andthe abutment was fastened to the implant fixture. Then a 30 Ncm tightening torque was applied to each abutment screw using a torquegauge. 10 minutes later, the same tightening torque was applied again.
5 minutes later, the removal torque of each abutment screw was measured using a torque gauge. The lower part of double locking abutment
screw is fastened to the fixture like single scerw abutment. A 20 Ncm
tightening torque was applied to upper part of double locking abutment screw. 10 minutes later, the same tightening torque was applied
again. 5 minutes later, the removal torque of double locking abutment
screw was measured using. This procedure was repeated 5 times, A
repeated load with a 50N and a 2Hz cycle was applied, 5mm awayfrom the center axis of the implant. After 50,000 cycles of repeatedload were applied, the removal torque was measured. To compare
postload removal torque Loss at each group, statistical analysis was
performed using Independent t-test.
In this limited study, there was no significant difference in the initial
removal torque between single screw abutment and double locking
abutment. Post-load removal torque of double locking abutment wassignificantly greater than single screw abutment. (P<0.05)
This limited study show that double locking abutment is effective toprevent.

Makiko Saita1, Masahiro Sugimoto2,3,Noriyuki Hoshi1, Katsuhiko Kimoto1
1

Kanagawa Dental University Department of
Prosthodontics & Oral Rehabilitation / Japan
2
Keio University Institute for Advanced Biosciences / Japan
3
Kanagawa Dental University Department of Pathology / Japan[Objective] Saliva is an important role in occlusion and mastication,
which improve systemic health and quality of life. The volume andchemical properties are major features of saliva. Although, masticatory
stimulation is known to increase the volume, the change of chemicalcomposition has not been clarified. Here, we conducted comprehensive metabolome analysis of hydrophilic small molecules in saliva. The
quantitative association between occlusal and masticatory stimulations and the salivary composition was investigated.
[Methods] The Ethics Committee of our university approved thisstudy. Saliva was collected from the following subjects who visited ouruniversity hospital: 1) Unstimulated saliva was collected from 3 patients with intact bilateral molar regions (Control group) and 3 patientswith defects of the bilateral molar regions (Experimental group) using
the spitting method, and subjected to metabolome analysis. 2) Unstimulated saliva (Control group) and stimulated one (Experimental group)
were collected using the spitting method and gum test, respectively,from 55 patients with intact bilateral molar regions, and subjected tometabolome analysis using capillary electrophoresis-mass spectroscopy.
[Results and Discussion] 1) Totally 137 metabolites were quantified.
Principle component analysis (PCA) differentiated metabolomic profiles between the Control and Experimental groups. 2) Totally, 106 metabolites were quantified. PCA showed clear differences between theControl and Experimental groups. These differences were more distinct in the comparison of gender and age differences. Metabolome
analysis revealed that occlusal and masticatory stimulations induced
both quantitative and qualitative changes in the salivary compositions.

Oral Session III Biology

16:30~17:10
Chairperson: Katsumi Uoshima (JPS)

III-1
LIF protects MSCs against hypoxia andserum deprivation-induced apoptosis
Yi Zhou, Xiaoqi Wang
Wuhan University

III-3

Introduction: Bone marrow-derived mesenchymal stem cells (MSCs)
have shown great promise for tissue regeneration. However, poor viability of transplanted MSCs has limited their therapeutic potential. Ischemia has been reported to be one of the main causes of MSCs death
during transplantation. The present study is sought to investigate
whether leukemia inhibitory factor (LIF), which plays an essential role in
the growth and maintenance of stem cells, could protect MSCs fromischemia-induced apoptosis.
Material & Methods: All experiments were carried out on rat bone18

WithdrawnOral Presentations

verting the graphics files,the fiber laser machine serving as the laser
scanning system to melt the organic binder in a short period of timeand sophisticated electronic lifting platform descending for a certain
distance of one layer thickness.By executing the single-layer generation cycle repeatedly which includes platform descending, layer paving, drying and scanning, 3D green parts are manufactured. Afterpre-sintering in a high temperature furnace, the polymeric binder ispyrolysed and the three-point bending strength of ZTA ceramic green
body reaches to 25.44±2.47MPa.Meanwhile, the linear shrinkage isminimum, what reveals that the goal of near net-shape is accomplished.What is more, the uniform pores of green part are also obtained, which can provide the basis for glass infiltration in the future
process.All in all, 3D green parts of ZTA ceramics are successfully
fabricated using slurry-based selective laser sintering, suggesting that
SLS has good potential to offer a desired technology breakthrough fordental restorations regarding with rapid prototyping methods.

III-4
The simplified conventional complete dentures
remains more cost-efficient after decade
Yasuhiko Kawai1,2, Hiroshi Murakami1,
Yoshiaki Takanashi1, Jocelyne Feine2
1

Nihon University School of Dentistry at Matsudo
2
McGill University Faculty of Dentistry

Objectives: Using a simplified method to fabricate conventional
complete denture is easier and more cost-efficient than the traditional
method in the short-term (Kawai et al 2005, 2010). However, it is notclear whether the usefulness of the dentures, patient satisfaction andoral health related quality of life (OHRQoL) might differ over a longer
period. The objective of this study was to determine clinical factors, aswell as patient perspectives, of new dentures fabricated with simplified(S) and traditional (T) techniques after a decade of use.
Methods: The study was s 10-year follow-up of a randomized controlled clinical trial (RCT) carried out from 2001 to 2003. One hundred
twenty (120) patients who randomly received complete dentures fabricated by two different methods, S and T, and who completed 6-monthfollow-ups (S: 54 and T: 49, total 103 subjects) were potential interviewees and were interviewed by telephone from September 2012 to December 2013. Variables included patient satisfaction, denture condition and OHRQoL.
Results: Twenty-nine S (54%) and 25 T (51%) participants responded to the interviews. Of those, 21S and 14T were still wearing the original study dentures. Ratings of denture satisfaction and OHRQoL byparticipants from both groups were similar (maxilla satisfaction; S: 80.7
T: 71.1, p=0.26, mandibular satisfaction; S: 69.9 T: 66.1, p=0.38 and
OHRQoL S: 107.7 T: 111.1, p= 0.46). Compared to 6-month follow-ups
ratings, there were significant decrease in maxillary T dentures;
6month: 91.7 10years: 71.1, p=0.008.
Conclusion: No differences in patient-based outcomes were detected when complete dentures were fabricated with simplified and traditional methods, both on the short and long term. This indicates that thesimplified method remains more cost-efficient than the traditional method over a 10-year period.

Oral Session IV Digital dentistry
Chairperson: Kazuyoshi Baba (JPS)

IV-2
Accuracy of digital impressions for
implant prostheses
Chikayuki Odaira, Hitoshi Ajioka, Shota Fukazawa,
Hisatomo Kondo
Department of Prosthodontics and Oral Implantology,
School of Dentistry, Iwate Medical University
Objectives
Recently, dental treatments have been digitalized with advance of
information technology. Particularly, optical impression by intra-oral
scanners is the focus of a lot of attention as a new method to reproduce
and measure three-dimensional shapes of oral tissue.
The purpose of this study is to evaluate the accuracy of digital andconventional impression techniques from the point of view of truenessand precision.
Methods
The reference model of the mandible was fabricated, in which abutments were connected to implants, and replicated using a vinyl polysiloxane impression material. A computer numerical control coordinate
measuring machine (CNCCMM) was used in measuring the reference
model and replicated models. Two intra-oral scanners (Lava COS(3M),
TRIOS(3shape)) were used in scanning the reference model. These
digitized data were loaded into 3D evaluation software (Focus Inspection, Nikon) and the distance between the center points of two abutments and the angle between the centerlines of two abutments were
calculated and assessing accuracy(trueness and precision). One-way
ANOVA followed by Bonferroni’s post-hoc comparisons tests were performed in all statistical analyses.
Results
The distance error of two abutments by the optical impression
showed slightly larger than the scan data from the reference and replicated models scanned with CNCCMM. The Angulation error byshowed no significant difference.
Conclusion
These results suggested that some of intra-oral scanners might
have comparable performance to conventional impression techniqueand could be useful in clinical practice.

17:00~18:00

IV-1
A self-made system for rapid
prototyping of dental ceramics
Ruibin Zheng, Tingting Lin, Jiangyuan Fan,
Siqian Wang, Yixin Mao, Jianfeng Ma
School & Hospital of Stomatology,
Wenzhou Medical University
Slurry-based selective laser sintering (SLS) is an advanced technique to fabricate complex-shaped ceramics in manufacturing industries.Through this way, three-dimensional (3D) ceramic parts can be
manufactured directly from CAD models without any specific tooling or
human intervention.This study describes the SLS process chain in dental ceramics of zirconia toughened alumina (ZTA) through self-maderapid prototyping system, beginning from slurry preparation,workpiece
fabrication to pre-sintering of the green parts. Accordingly, ZTA ceramic slurry is prepared by ZTA powder, the binder polyvinyl alcohol anddeionized water.It is worth mentioning that a self-made rapid prototyping system comprising three parts are assembled:computer with CAD
software designing the crown shape, the cutting layer software con-19

Oral Presentations

cant with the lithium disilicate crown generally showing a higher value(P<.001). The difference in marginal gap was not statistically significant (P>.05) and both groups showed fitness levels that can be clinically accepted.

IV-3
Computer-guided template to makescrew-access hole in implant restoration
Du-Hyeong Lee1, Hye-Won Kang2
1

Department of Prosthodontics, School of Dentistry,
Kyungpook National University
2
Department of Dental Science, School of Natural Science,
Kyungpook National University
Several articles have described techniques to facilitate making thescrew-access hole. Photographs containing the location of the screw
channel or radiographs showing the implant axis provide clinicianswith second-hand information of the screw position. Staining a small
spot on the occlusal surface of the restoration or using a vacuum-formed template are useful laboratory techniques for indicating thestarting point of drilling. Futhermore, as an advanced system, a drilling
guide using vacuum-formed template and pattern resin was introduced.
However, the system has been based on conventional manual processes, and has some limitations when applied intraorally. Herein, advanced approaches for fabricating a guide with a handpiece sleeveusing digitalized techniques are introduced. The digital processes facilitate accurate guided drilling through the restoration and enables thecooling water to reach the drilling area.

IV-4
Fitness of lithium disilicate CAD/CAM crowns :A multicenter clinical study
So-Hyoun Lee, Se-Jin Nam, Young-Chan Jeon,
Chang-Mo Jeong, Mi-Jeong Yun, Jung-Bo Huh
Department of Prosthodontics, Busan National University,
School of Dentistry
Objective. This multicenter clinical study aimed to compare the fitness of the metal ceramic crown made from traditional method and thatof the lithium disilicate crown utilizingCAD/CAM system.
Materials and methods. This study was approved by Pusan National
University Dental Hospital’s IRB. A total of 21 patients’ (seven for eachof the three dental clinics) abutment teeth were prepared according to
the conventional methods. Two kinds of prosthetic restorations were
fabricated, a metal ceramic crown using traditional method and a lithium disilicate crown utilizing CAD/CAM system (CEREC AC system) per
one patients’ abutment teeth. Two silicone replicas were produced per
restoration at the abutment sites and then seated. Each of which was
sectioned in the center of buccolingual and mesiodistal direction tomeasure the marginal and internal gap. A total 10 reference points per
tooth were set, respectively 5 points in each direction, to measuregaps. The measuring microscope (AXIO) and I-solution software wasused to measure the thickness of the silicone film at the selected
points..Means of the gap width of each center were compared using
one-way analysis of variance with Tukey's multiple comparison test at
a significance level of 0.05
Results. In the comparison of the differences among each center, nosignificant difference in gap width was found in the lithium disilicate
crown (P>.05) and the metal ceramic crown (P>.05). Significant differences in the MCC group and LDC group were showed reference pointsof buccolingual direction (P<.001)and reference points of mesiodistal
direction (P<.001). As for the marginal gap, no significant difference
was noted (P>.05). The internal gap was significantly bigger in thelithium disilicate crown’s axial and occlusal surfaces (P<.001).
Conclusion. The difference in internal gap was statistically signifi-

20

Poster Presentations

April 10 (Fri), 2015 Room B (Mochizuki)

1. Clinical Epidemiology and Prosthodontics

the lips healed about 1 month later without any medicine.
There were several articles about the allergy to nichrome. It mightcause oral disease, nephrosis, and even the decreasing of the patient’s WBC. Doctor Pan considered that, base metal could release
many kinds of metal ions, which would affect the mucous cells, and theimmune systems, to cause DTH. Doctor Hildebrand thought that Ni
was the easiest metal to cause allergy, followed by Cr, and Co. And it
belonged to T cellular immune response. There wasn’t any article
about the allergy to the all ceramic crown till now after searching all thearticles of the database.
After all, might it be the adhesives that cause the symptoms of ourpatient with the all ceramic crowns? The purpose of this report was towarn colleagues, that all ceramic crowns could also cause allergy, for
the use of adhesives, disinfectants and other chemical agents.

P-1
Occlusal reconstruction of patients withcongenital dentition defect and crossbite
Shanshan Gao, Yang Liu, Jie Min, Dandan Yu, Haiyang Yu
West China Hospital of Stomatology,
Sichuan University, Chengdu, China
Objective: The aim of this study was to discuss the effect of applying
splint pad removable partial denture for occlusal reconstruction in patients with congenital dentition defect and partial crossbite.
Methods: By analyzing the facial and oral condition, the problems of
the patient mainly included six congenital dentition defect, insufficientheight of the 1/3 lower faces, crossbite of the right posterior area andthree retained deciduous teeth. Asymmetry of the before and after thejoint clearance was confirmed by CBCT of temporomandibular joint(TMJ). We decided to elevate and reconstruct the occlusion. Considering congenital absence of part of the permanent teeth germ, several
retained deciduous teeth and poor condition of the residual ridge of themandibular, we used splint pad removable partial denture to repair inorder to satisfy the requirement of the patient for retaining the remaining teeth and spending less. During this process, we applied splint
pad to redefine the occlusion. When the patient felt no discomfort withthe splint pad, the occlusion relationship was recorded and transferredto the full adjustable articulator for further restoration of removable partial denture. In order to evaluate the ability of adapting to the new position of occlusal muscles, patient is reviewed for measurements of muscle function every other month during the first half year.
Results: With the restoration, the face type and aesthetics of patient
get improved significantly. The temporalis and masseter muscle electromyography is also ameliorated obviously after permanently repair.
Additionally, the position of the joint is improved and the before andafter the joint clearance is uniformed.
Conclusion: Standardization of occlusal reconstruction with removable partial denture can improve the appearance and mastication
function of the patient. After the occlusal reconstruction, the position of
the joint is ameliorated and the function of temporalis and massetermuscle is increased significantly.

P-3
One case: Combination of restoration withorthodontics for trauma
Lei Chen, Weidan Zhang
Department of stomatology of Xiangya Hospital ofCentral South University
Jiaming Yan, male, 17 years old. The upper alveolar bone fractured
because of a car accident. He came to us with disordered occlusion
after monomaxillary fixation for 3 weeks.
Ph: 12, 13, 14, 41 had lost, 31 was residual crown and the RCP was
finished, the anterior teeth wereⅠo cross bite with the posterior disordered. We found that his mandible could be pushed afterward till theanterior teeth took on edge to edge articulation. So we considered that
his occlusal disorders were due to the introversion of 11 and 21 bytrauma, and the mandible had to move forward in order to make themolars bite.
So we raised the acclusal plane of the molar teeth, in order to push
the introvertive anterior teeth to their physiological place, by using theremovable appliance. And we made another removable denture to restore 31 and 41. The upper anterior teeth were moving forward with thegap of the molars decreasing, by the maintenance of the pushingstrength and the regulation of the thickness of the occlusal pad. 3
weeks later, the occlusal relation went normal. So we removed the acclusal pad, and the removable partial denture was used to restore theupper anterior dentition defect.
Eventually, it took us only 2 months to regular the occlusal relation
and restore the dentition. We planed to use implant prosthesis as thepatient grown up.
The purpose of this case was to provide a new treatment for maxillofacial trauma. It could not only regular the occlusal relation, recovered the appearance, but also restore the masticatory function, by theremovable appliance, in the early days of trauma; besides, it was easier for the patient to maintain oral hygience; furthermore, it could also
help keep the space of the dentition defect for implant restoration later.

2. Fixed/Removable Prosthodontics

P-2
Ceramic crown allergy-One case report
Lei Chen, Weidan Zhang
Department of stomatology of Xiangya Hospital ofCentral South University

P-4

Weiqiu Liu, female, 43 years old, came to us with the mucosa of the
red lips swelling, dissipating and peeling, especially the upper lip. We
made a diagnosis as “chronic cheilitis”, but the symptoms didn’t growany better during more than 1 year with all kinds of medicine.
Then we found that the symptoms occured since she worn the 1222 PFM union crown restoration 2 years ago, and she never worn any
jewelry of base metal. So we dismantled the PFM union crown restoration, and then the symptoms disappeared 1 month later without any
medicine. Therefore, we created 4 Cercon all zircon ceramic crowns
for her, considering the allergy to the base metal. However, the symptoms came back just 1 month later, and it lasted for more than 3 months.
So we had to dismantle all the 4 ceramic crowns, and the wound of

Influence of tray relief and impression material
on impression pressure
Masatoshi Iwasaki, Misao Kawara, Yoshihiro Iwata,
Yoshihiro Komoda, Sayumi Inoue, Takashi Asano,Takashi Iida, Osamu Komiyama
Nihon University School of Dentistry at Matsudo

21

Poster Presentations

Conclusion: The present results suggest a negative correlation between residual bone height and bone density of the edentulous mandible.

Objectives:
To investigate the influence of the thickness of relief in tray and characteristics of the impression material on impression pressure for an
edentulous model.
Methods:
Alginate impression material (Algiace Z; AL), silicone impression
material (Exadenture; ED), polyether impression material (Impregum
soft medium body; IG), and a maxillary edentulous model were used.
The tray relief consisted of no relief, 1.40-mm-thick base-plate wax,
and 2.80-mm-thick base-plate wax. Miniature pressure sensors wereembedded at the incisive papilla, the anterior point and the deepest
point of the mid-palatal suture. These measurement points were included within the relief area. The mixing time prior to the experiment was
set at 60-s for each material. The measurement of impression pressure
started immediately after loading. The duration of the measurement
was 150-s, and the sampling rate during all measurements was 10 Hz.
The static load to the trays during measurements was set at 2 kgf. Fivemeasurements were taken for each material using three types of customized trays. The mean impression pressures at each point in thethree trays were calculated at 10-s from loading in each materials.
Results:
The mean impression pressures of AL, ED and IG in the incisive
papillawere
8.56&plusmn;1.58,
7.75&plusmn;2.23,
and
7.79&plusmn;0.96 kPa. The mean impression pressures of AL, ED, andIG in the anterior point were 6.11&plusmn;0.43, 6.02&plusmn;0.39,
and 5.62&plusmn;0.31 kPa.The mean impression pressures of AL, ED
and IG in the deepest point were 4.78&plusmn;0.36, 4.57&plusmn;0.50,
and 4.86&plusmn;0.11 kPa.The impression pressures at each measurement point were significantly dependent on the impression materials (P<0.05) and tray relief (P<0.05).
Conclusion: Impression pressure is dependent on the thickness of
the relief and the rheology of the impression material.

P-6
3D-FEA of the stress distribution for
the abutment toothTomonori Isogai, Teruo Ino, Daisuke Teshigawara,
Satoshi Endo, Hiromasa Noro, Masanori Fujisawa
Meikai University
To analyze the effect under various Young’s modulus on stress distribution of a pulpless tooth with fiber-post reinforced composite resin,
three-dimensional finite element model of maxillary central incisor without coronal structure was constructed. The model simulated the tooth
restored with a porcelain fused-to-metal crown (PFM).
Steady static load of 150[N] was applied on the incisal edge of lingual surface of incisor at an angle of 45 degrees. Then stress distribution at an interface between post-and-core and dentin was evaluated.
Moreover, stress distribution of adhesive resin cement at the margin
was also evaluated.
To evaluate stress distribution, it entailed composite resin at post
part of varying Young’s modulus and core part with steady value of
13.2[GPa]. Furthermore, core part under various Young’s modulus withsteady value of 8.4[GPa] for post part was also analyzed.
As decreasing Young’s modulus of post part, stress decreased atinterface between post-core and dentin in root apex region. Also as
increasing Young’s modulus of core part, stress decreased at adhesive
resin cement at the lingual margin of PFM, while stress increased atlingual interface between post-core and dentin.
From the results above, it is suggested that decreasing Young’s
modulus of post part allows suppression of stress concentration at theroot apex region, and increasing Young’s modulus of core part suppress the delamination of adhesive resin cement at crown margin andreduce loose post-core from radicular tooth.

P-5
Analysis of bone density in edentulous
mandible using CT images
Sayumi Inoue, Misao Kawara, Manabu Masuda,
Ryuto Asakawa, Hiroshi Suzuki, Toshikazu Kuroki,Takashi Iida, Osamu Komiyama

P-7

Nihon University School of Dentistry at Matsudo
Objectives: To investigate the correlation between bone density ofthe edentulous mandibular ridge crest and residual bone height inedentulous subjects using computed tomography (CT) images.
Methods: The edentulous areas examined consisted of 194 regions(47-males and 50-females, mean-age 76.0 years) of CT examinations
conducted. All CT examinations were performed using a multislice CT
scanner and analyzed on an imaging workstation. Mandibular residualbone height, the CT value at the alveolar ridge crest, and the CT value
at the lowest point of the mandible measured from CT images at a position 10-mm distal from the mental foramen. Mandibular residual boneheight was classified into the following three groups: Class-1 (>24mm); Class-2 (16-24-mm); and Class-3 (<16-mm). To evaluate bonedensity, ratios of the CT value at the alveolar ridge crest to that at thelowest point of the mandible were calculated for all subjects.
Results: The mean mandibular residual bone heights were 27.2±2.1
mm (Class-1), 19.5±2.3 mm (Class-2), and 13.0±2.2 mm (Class-3).
The mean CT values at the alveolar ridge crest were 1014.6±262.1(Class-1), 1274.0±258.2 (Class-2), and 1451.1±199.3 (Class-3). The
mean CT values at the lowest point of the mandible were 1722.5±165.4(Class-1), 1722.6±148.2 (Class-2), and 1720.5±125.1(Class-3). The
mean ratios of the CT values at the alveolar ridge crest to the lowest
point of the mandible were 0.59±0.15 (Class-1), 0.74±0.14 (Class-2),
and 0.85±0.12 (Class-3). A significant difference was evident in theratios of the CT values at the alveolar ridge crest to the lowest point of
the mandible among Class-1, Class-2, and Class-3 (P<0.05).

Withdrawn

P-8
Restoration of partially edentulous patient byusing an angled locator® root attachment :case report
Min-Hee Ban, Han-Sung Joo, Mong-Sook Vang,
Hong-So Yang, Sang-Won Park, Hyun-Pil Lim, Kwi-Dug Yun
Department of Prosthodontics, Chonnam National University
In the restoration of distal extension saddles, lack of adequate support results in bilateral and unilateral displacement of removable partial
dentures, causing excessive force to the abutments and weakness ofmasticatory force. As the canine or molar, which was used as abutments of existing partial denture, was lost, function of the denture wasseverely compromised. If decay is extensive in the abutments in key
position like canine and there is limited tooth structure, a stud type attachment can be a treatment of choice for increased support and retention of partial denture.
A 82-year-old woman sought treatment that would provide her witha stable removable prosthesis. The patient’s primary complaints werepoor retention due to fallen out of maxillary anterior prosthesis and re-22

Poster Presentations

duced mastication of the existing denture. The patient had the fallenout maxillary fixed prosthesis due to secondary caries, multiple caries,
moderate alveolar bone loss and crossbite. The teeth with severe mobility were extracted resulting edentulous areas in both arches. Because the tooth structure of left maxillary canine, which was used asabutment in the existing denture, was not sufficient due to secondary
caries and it was opposed with a fixed restoration, a stud type attachment was considered for increased support and retention. Twenty degree of inclined Locator® root attachment was used to make the longaxis of labially inclined left maxillary canine identical with the path ofinsertion of the denture. After 2 weeks of definitive denture delivery, theplacement of nylon was done. At a recall appointment 6 months later,nylons had not been replaced. The patient was satisfied with increased
support and retention of the denture. This case presents the use of
Locator® root attachment system on retained root located in functionally important area, providing increased support and retention.

P-10
Case report: rehabilitation of maxillary
edentulism with implant fixed prosthesis
and partial denture
Jee-Hwan Kim, Soo-Hyun Yim
Department of Prosthodontics, School of Dentistry, Yonsei University
Treatment options for full edentulous patients are complete denture,
implant assisted overdenture and implant fixed prosthesis. Many factors such as age, gender, oral hygiene care, economic status, extent ofalveolar resorption, residual bone and patient’s needs are considered
for treatment decision.
In this case, the patient is a middle-aged woman demanding an
implant fixed prosthesis for edentulous maxilla. Sufficient residual alveolar bone is necessary for implant fixed prosthesis, but in this case, thepatient had an insufficient amount of alveolar bone for implant placement in anterior maxilla. Because it was difficult to restore full arch withimplant fixed prosthesis, surveyed implant fixed prosthesis was installed in bilateral posterior regions and Kennedy Class IV RPD treatment was ensued. 5 years of follow- up period showed stable results.
In this case, posterior regions restored with implant fixed prosthesis
produced effective masticatory function, and partial denture using surveyed implant crowns and manufactured without anterior clasps had
improved esthetics and patient satisfaction. Evidence is not sufficientfor usage of implant surveyed crown unlike a natural tooth, so indication should be carefully selected. However, implant placement andpartial denture design with careful consideration can produce satisfactory results with a good prognosis for both dentist and patient.

P-9
Study about reproducing parallel relationshipin abutment preparation ofremovable partial denture
Jai Young Koak, Seong Joo Heo, Myung Joo Kim,
Seong Kyun Kim, Jai Bong Lee, Jung suk Han,
Sung Hun Kim, Ho Beom Kwon
1. objectives
Objective of this study is to evaluate the accuracy of resin jig index
method suggested by Seoul National University Dental Hospital that isused to reproduce parallel relationships between guide planes ofstone model milled by surveying machine in oral preparation.

Keywords :Full edentulous; Surveyed crown; Removable partial
denture2. methods
A mandible RPD practice model of Kennedy Class II modification 1
missing #35, 36, 46, 47 teeth was used. Using liquid silicone (KE-1300,
Shinetsu, Japan), an impression of RPD model was made and 16 yellow stone models was obtained from the impression. One of the yellow
stone models was chosen arbitrarily, and duralay resin caps were built
on #34, 36, 45 teeth of the stone model. After resin hardened, themodel was surveyed on a surveying machine to form parallel guideplanes according to path of insertion. Then, duralay resin index wereobtained and used to form proximal planes and undercuts for retentive
arms on #34, 36, 45 teeth of 15 remaining yellow stone models by handusing high speed bur.
Proximal planes and undercuts for retentive arms on #34, 36, 45
teeth of all 16 yellow stone models were taken picture by oral camera.
Using Adobe Photoshop CC (Ireland, v.14.0), areas of proximal planes
and undercuts for retentive arms on #34, 36, 45 teeth of all models
were measured and compared between areas of model formed by surveying machine and those of models formed by hand.

P-11
Rehabilitation of severely worn dentition with
fixed and removable partial denture
Sunyoung Choi, Jung-suk Han, Jai-bong Lee,Sung-hun Kim, In-sung Yeo
Department of Prosthodontics and Dental Research Institute,
College of Dentistry, Seoul National University
Severely worn dentition declines the masticatory function as well as
esthetics. The rehabilitation of such cases is regarded as one of themost challenging and demanding treatment process for both dentists
and patients. Severely worn dentition combined with partial edentulous
space is even worse in the respect of the limited space for restoration.
The ultimate goal of the rehabilitation should be the development of
normal healthy function of the masticatory apparatus. The restoration
involves the development of sufficient restorative space and proper
anterior guidance, while simultaneously fulfilling esthetic, occlusal, andfunctional parameters essential to long-term success. This report described the multidisciplinary dental treatment of a 76-year-old malepatient who have had partial edentulism and severe wear of remained
teeth. As a result, the occlusal function and esthetics were improved
with fixed and removable dental prostheses in increased vertical dimension.

3. results
Areas of proximal planes of #34, 36, 45 teeth, undercuts for retentive
arms of clasp on buccal side of #34, 45 teeth, and plane for reciprocalarm of lingual side of #36 teeth were measured and compared.
1) Proximal plane and undercut for retentive arm of #34: differenceof 3.67% and –6.59%
2) Proximal plane and plane for reciprocal arm of #36: difference of
24.15% and 12.96%
3) Proximal plane and undercut for retentive arm of #45: differenceof -6.32% and 24.23%
Key Words; surveying, abutment preparation, resin jig, parallel relationshipKey words: tooth wear, worn dentition, partial edentulism, verticaldimension of occlusion

23

Poster Presentations

3. Oral Implantology

tients. Ninety-eight percent of these were custom made abutments
made by use of CAD/CAM system. Among them, titanium abutments
were 68% and zirconia abutments were 23%. Seventy-six percent oftitanium abutments were used in the molar region, 64% of zirconia
abutments were used in the anterior region.
Discussion
In this study, titanium abutments made by use of CAD/CAM systemwere most selected (68%). As a reason to select these abutments, it
may be greatly affected by implant position. On the select of used materials, titanium was selected in the molar region due to resistant to the
occlusal force. On the other hand, zirconia was selected in the anterior
region due to require aesthetics demands and stability of soft tissue.

P-12
Influence of implant distribution on implantof maxillary implant overdenture.
Toshihito Takahashi, Tomoya Gonda, Akiko Tomita,
Yoko Mizuno, Yoshinobu Maeda
Department of Prosthodontics, Gerodontolgy and Oral Rehabilitation
Osaka University Graduate School of DentistryP-14

Objective: Although there have been no consensus or guideline
about implant configuration in maxillary IODs, various numbers anddistributions of implant has been applied. Therefore, the purpose ofthis study was to examine the influence of implant number and distribution from the aspect of implant strain under maxillary IODs.
Materials and Methods: A maxillary edentulous model with implants
and experimental overdentures were fabricated. Four strain gauges
were attached on the implant and the implants were installed bilaterally in anterior, premolar and molar area. Seven supportive types were
tested: supported by two independent implants (IIa, IIp, IIm), by four
independent implants (IVap, IVam, IVpm) and by six independent implants (VI). A vertical occlusal load of 98 N was applied and the strainof each implant was compared by the one-way analysis of variance (P= 0.05).
Results: In the strains of anterior implant, there were significant differences among IIa, IVam, IVap and VI type (P<0.05) and it was the
maximum in IIa and the minimum in VI. In that of premolar implant,
there was significant difference between IIp and VI (P<0.05). In that ofmolar implant, there were significant differences between IIm and theother situations (P<0.05) and there was no significant difference
among IVap, IVpm and VI.
Conclusions: Anterior two independent implants supporting
overdenture were observed the largest strain and should be avoided
for supporting overdenture. For maxillary overdenture support, 4 independent implants in premolar and molar regions or 6 implant distributed from anterior to molar area should be utilized.

Treatment effects of prostheses in patientswith mandibular distal-extension edentulism
Toshifumi Nogawa, Yoshiyuki Takayama, Atsuro Yokoyama
Graduate School of Dental Medicine, Hokkaido University
Purpose: The aim of this study was to compare masticatory performance, occlusal force and oral health-related quality of life (OHRQoL)
between implant supported fixed prostheses (ISFPs) and removablepartial dentures (RPDs) in patients with mandibular distal-extension
edentulism.
Materials and Methods: The subjects were recruited from patientsusing ISFP or RPDs with mandibular distal-extension edentulism. Masticatory performance was evaluated according to the glucose extraction from chewed gummy jelly. Occlusal force was measured witha pressure-sensitive sheet and computer analysis. The Japanese version of the Oral Health Impact Profile (OHIP-J) was used to evaluate
OHRQoL. The masticatory performance, occlusal force and OHIP-J
scores of the ISFP group and RPD group were compared using the
Wilcoxon rank sum test. In patients with the unilateral mandibular distal-extension edentulism, the masticatory performance of the prosthesis side was compared with that of the natural dentition side using the
Wilcoxon signed-rank test. Multivariate logistic regression analysis was
employed with the OHIP-J score as a dependent variable.
Results: Nineteen patients with ISFPs (mean age: 60.2 years) and25 patients with RPDs (mean age: 63.3 years) were recruited in thisstudy. There was no significant difference between the two groups withregard to the masticatory performance and occlusal force. In the unilateral ISFP group, there was no significant difference of masticatory
performance between the natural dentition side and prosthesis side,
whereas there was significant difference in the unilateral RPD group.
The OHIP-J score was significantly lower in the ISFP group than in the
RPD group. Multivariate logistic regression analysis showed thatyounger age, RPDs and lower occlusal force were significantly associated with a higher OHIP-J summary score, indicating lower OHRQoL.
Conclusion: Our results suggest that ISFPs are superior to RPDs
with regard to masticatory performance, occlusal force and OHRQoL
in patients with mandibular distal-extension edentulism.

P-13
Clinical evaluation of implant
abutment design and materials
Yosuke Shinozaki, Yu Takaesu, Emiri Mizumachi,
Michiko Sasaki, Takashi Matsuura, Hironobu Sato
Department of Oral Rehabilitation, Section of
Fixed Prosthodontics, Fukuoka Dental College
Introduction
Recently, implant prostheses are demanded from not only function
but also aesthetic element. The abutment of implant design is important to achieve these demands. By the introduction of CAD/CAM system, it was possible to use many kind of materials and design of implant abutments. The aim of this study is to investigate the kind of
implant abutments with completed cement-retained fixed implant-supported restorations and discussed about used materials and design inFukuoka Dental College hospital.
Materials and Methods
Fifty-six patients treated by cement-retained fixed implant-supported restorations were used in this study from 2008 to 2012. Those abutments were investigated about a method of making, used materials
and the location of implant.
Results
One hundred forty eight implant abutments were used for 56 pa-

P-15
Influence of cementation gap on
the retrievability of implant fixed
prostheses with a Lingual Slot
Tae-Kyun Kim, Jung-Wan Park, Kyoung-Bae Jeon,
Du-Hyeong Lee, Kyu-Bok Lee
School of Dentistry, Kyungpook National University

24Poster Presentations

Although cement-retained implant restorations have many advantages, such as aesthetics, occlusion, expense, and passive fit, as
compared to screw-retained implant restorations, the lack of retrievability when restoration removal is required is a major limitation.
The purpose of this study was to establish a clinical guideline forgeneration of a cementation gap for retentivity and retrievability by creating a retrievable cement-type slot(RCS) on the lingual side of the titanium abutment for retrievability in a cement supporting implant fixed
prosthesis and to measure the removal torque of prosthesis during
development of a zirconia prosthesis as a sealant for the upper region.
The results of this study showed that there was statistically significant difference between 30 μm and 50 μm of cementation gap as well
as between 35 μm and 50 μm of gap in the removal torque of prosthesis, whereas there was no difference between 30 μm and 35 μm. These
data indicated that the removal torque was depending on the cementation gap of zirconia prosthesis. The findings of this study suggest thatwhen cementation is generated with permanent cement for a cement-supporting implant fixed prosthesis, retrievability should be secured by creating a lingual slot and controlling the cementation gap.

ly in partially edentulous mandible with unilateral residual premolars.
Mandible was then restored with implant retained overdentuer using
loactor.
This case report is to study the effectiveness of implant assisted
overdenture.

4. Prosthodontics-Related Biosciences

P-18
Comparison of two citrus flavonoids on
Streptococcus mutans
Jiaxi Yue, Siying Liu, Hongye Yang,
Fangfang Song, Cui Huang
School of Stomatology, Wuhan University
We compared the effects of two types of citrus flavonoids, naringenin and quercetin, on the growth of and biofilm formation by Streptococcus mutans. Minimum inhibitory concentrations, growth curves, andbiofilm inhibition rates were determined to assess their effects macroscopically. The results showed that both flavonoid types effectively inhibited growth and biofilm formation, although naringenin tended tohave a slow but stable effect and quercetin had a rapid effect but became weaker over time. Confocal laser scanning microscopy and fieldemission scanning electron microscopy were used to observe the morphology and structure of S. mutans and its biofilm caused by the two
drugs; the results revealed that that the naringenin treatment resulted
in only small, loose bacterial clumps, whereas the quercetin treatment
resulted in larger, denser structures. Further, to investigate the possible
underlying mechanisms, bacterial aggregation, bacterial surface hydrophobicity, and real-time PCR for gtfB, gtfC, comD, comE, and luxS
mRNA expressions were assessed. The results obtained were agreed
with those obtained for the macroscopic observations and photomicrographs. Finally, the MTT test using human dental pulp cells was used
to investigate cytotoxicity, revealing that both naringenin and quercetin
exhibited favorable compatibility. Thus, our results indicated that these
citrus flavonoids had different modes of action and that both naringenin and quercetin have potential clinical use as anti-caries drugs.

P-16
A case report: Immediate restoration of
single implant in anterior maxilla
Jung Hyun Jung, Kim Jee Hwan
Department of Prosthodontics,
Busan National University, School of Dentistry
Implant immediate placement and loading reduces surgery tim andnumber. It also reduces the possibility of hard and soft tissue resorption. If primary stability is sufficient, immediate loading can be applied
to anterior region. For immediate loading of single implant, primary stability of minimum 32-35 Ncm is required. After immediate implant
placement, temporization on the day of surgery provides comfort to apatient and maintains and shapes soft tissue during a healing period.
In case of immediate implant placement right after extraction, accuracy may be compromised for immediate restoration using guided surgery. In this case report, immediate restoration of single implant in anterior maxilla was done using Ti base abutment and CAD-CAM milled
PMMA block and it produced stable treatment results.

P-19
P-17

The physicochemical properties andbiological activity of CB/CS in vitro

Full mouth rehabilitation with implant assisted
overdenture: Case report

Jian Liao1, Xing Liang2, Yunmao Liao2, Yong Wang1
1

Sang-min Oh

Affiliated Hospital of GuiYang Medical University
West China Hospital of Stomatology, Sichuan University

2

Yonsei University, College of Dentistry
Intruduction:Dental implants have become an often used alternative
to replace missing teeth,but the lack of alveolar bone,which was due toperiodontitis,bone disorders,traumar dysplasia,or progressive alveolarbone absorption,often affect the success rates of dental implants seriously.Bone augmentation is one of the main methods to solve the lackof alveolar bone in implant dentistry.The aim of this study was to investigate the feasibility of calcinedbone/chitosan composite materials asbone graft substitutes in alveolar bone argumentation.
Materials and Methods:Calcined bone(CB)obtained by sintering
bovin bone, The porous calcined bone / chitosan composite materials
were prepared by solution blending method. The prepared CB and CB/
CS were characterized by X-ray diffraction(XRD), Scanning electron
microscopy(SEM) and Fourier transform infrared(FTIR), and then Adhesion and proliferation of MG63 osteoblast-like cells were evaluatedby SEM and CCK-8 assay, In addition, Osteogenic differentiation was

After multiple tooth extraction due to generalized periodontitis, alveolar bone resorption is severe and residual teeth are located at strategically unfavorable positions. In such case, restoring full or partial
edentulism with conventional denture may produce unsatisfactory outcome for both dentist and patient.
On the contrary, treatment using implant can enhance patient satisfaction and function. When implant and removable prosthesis combined treatment is provided for a patient with severe bone resorption, it
can create excellent results.
In this case report, a patient with moderate to advanced periodontitis in both maxilla and mandible was rehabilitated with implant assisted
overdenture after multiple tooth extraction. 6 implants were placed infull edentulous maxilla, which was then restored with implant supported overdenture using milled bar. 2 implants were placed contralateral-25

Poster Presentations

because of the protective oxide coating that spontaneously forms on
their surface. We fabricated titania nanosheet (TNS) structures on titanium surfaces by NaOH treatment to improve bone differentiation ontitanium alloy implants. The cellular response to TNSs on Ti6Al4V alloy
was investigated, and the ability of the modified surfaces to affect osteogenic differentiation of rat bone marrow cells and increase the success rate of titanium implants was evaluated. The nanoscale network
structures formed by alkali etching markedly enhanced the functions ofcell adhesion and osteogenesis-related gene expression of rat bonemarrow cells. Other cell behaviors, such as proliferation, alkaline phosphatase activity, osteocalcin deposition and mineralization, were also
markedly increased in TNS-modified Ti6Al4V. Our results suggest thattitanium implants modified with nanostructures promote osteogenic differentiation, which may improve the biointegration of these implants
into the alveolar bone.

evaluated by measurement of alkaline phosphatase(ALP)activity as
well as gene expression analysis of osteogenic markers using realtime-RT- PCR.
Results:Results showed that the composite present high surface
area and porosity, good biocompatibility and promote cell viability andproliferation, In vitro test show that osteoblast-like cells on the composite surface are able to adhere, proliferate,and migrate through thepores.
Conclusions:The calcined/chitosan composite has good biocompatibility and osteoconduction. It is a potential bone graft substitutes inbone regeneration for implant dentistry.

P-20

Withdrawn

P-21

P-23

Investigation of protein adsorption on
dental prosthesis

Zirconia coated with calcium
phosphate as a bone substitute

Akiko Miyake, Satoshi Komasa, Yoshiya Hashimoto,
Yuichiro Tashiro, Hiroshi Nishizaki, Kazuya Takahashi,
Yutaka Komasa, Joji OkazakiJung-Wha Lee, Inho Cho, Lee Joon Seok, Song Young Gyun
Hyunyoung Kim, Eunkyung Kim
Dankook Univ. of Dentistry

Osaka Dental University
PurposeThe aim of this study was to evaluate the possibility of a porous zirconia coated with bioactive materials as a bone substitute.
Materials and methods
Twelve adult New Zealand white rabbits were used in this study.
Each had four transosseous defects in the calvaria. The defects werefilled with zirconia particles, zirconia coated with HA particles and zirconia coated with β-TCP particles. One defect was left empty as thecontrol group. 2, 4 and 8 weeks after surgery, the rabbits were sacrificed and the specimens were taken for the histologic and histomorphometric evaluation of new bone formation.
Results
After 2 and 4 weeks there was significant difference between control
group (p<0.05) and experimental groups but not between experimental groups. The new bone formation of control group was smaller thanthat of experimental groups (p<0.05). Comparing the mean of newbone formation area between the experimental groups, the zirconia
coated with β-TCP group was higher (p<0.05). 8 weeks after surgery,there were significant differences between control and experimentalgroups. Also, zirconia coated with β-TCP group showed higher meanof new bone area than other groups (p<0.05). Comparing the zirconia
and the zirconia coated with HA group, the mean of new bone formation area of the zirconia coated with HA group was higher than that ofzirconia group, but there was no statistical difference.
Micro-CT analysis was performed but because of the artifact effectof zirconia, difference between the groups could not be evaluated.
Conclusion
Zirconia coated with β-TCP showed better capacity as a bone substitute than other materials in this study. This means that biologicallyinert zirconia can act as a scaffold in the stress bearing area and the
new bone formation can be accelerated by the coating of bioactive
material like β-TCP

Objective: A quartz crystal microbalance (QCM) is a highly sensitiveand practical device for in situ monitoring of protein adsorption. In thisstudy, poly(methyl methacrylate) (PMMA) sensors that imitate denturesurfaces were prepared using a thin-film magnetron to spin-coat
PMMA onto gold-plated quartz. We discuss the quality of the PMMA
and titanium sensors and evaluate the potentials of high-frequency
PMMA and titanium QCM sensors by investigating the binding between the PMMA and titanium QCM sensors and proteins.
Materials and methods: To prepare the PMMA-coated sensors,
PMMA in ethyl acetate was used to coat the PMMA thin film onto thegold electrode of the quartz crystal at a spin-coater. Titanium sensors
were prepared by sputtering. The surface topologies and roughness of
the PMMA, titanium, and bare QCM sensors were evaluated by scanning probe microscopy (SPM). The PMMA QCM sensors were characterized using Fourier-transform infrared (FTIR) spectroscopy and thecompositions of the PMMA and titanium coatings were determinedusing X-ray photoelectron spectroscopy (XPS). QCM measurements
were used to quantify the protein related to adhesion of denture plaque.
Results: We fabricated PMMA QCM sensors by spin-coating. SPM,
FTIR, and XPS analyses showed that a thin PMMA film with the originalcomposition was coated onto the bare QCM sensor. The titanium sensor had a thin titanium film coated onto the bare QCM sensor. Significantly more protein adhered to the PMMA and titanium QCM sensors
than to the bare QCM sensor.
Conclusion: This study describes the technical basis for observing
the adsorption of proteins on denture surfaces, and may contribute to
the development of denture cleaners that prevent biofilm formation.

P-22
Effect of TNS-modified structure of titanium
alloys on cell differentiation
Satoshi Komasa, Yoichiro Taguchi, Tetsuji Kusumoto,
Hiroshi Nishizaki, Joji Okazaki
Osaka Dental University
Titanium alloys are the most frequently used dental implants partly

26

Poster Presentations

bacterial plaque derived biofilm formation.

P-24

Materials and Methods: PMMA sheets were dipped in 0.5wt% PMBPAz and dried in ethanol atmosphere for 20 min with ultraviolet irradiation for 2 min. The PMBPAz coating on the PMMA sheets were examined by static contact angle of air bubble in water and X-ray photoelectron spectroscopy (XPS). The anti-adhesive effects against bacterial plaque accumulation was evaluated by a S. mutans biofilm formation assay. The durability of the PMBPAz coatings was determined bysoaking test for 1 week.

Genetic association between VEGF
polymorphisms and BRONJ in
Korean population
TH Kim, H Choi, Jae-Hoon Lee, J-H Kim
Department of Prosthodontics, Oral Science Research Center,
Yonsei University College of Dentistry

Results: The static contact angle of air bubble on PMMA and PMBPAz-coated PMMA sheets in water were 130 and 160 degrees. Successful coating was also confirmed by XPS, which detected spectra for
nitrogen and phosphorus elements only on the MPC polymer-coatedsurface. Moreover the PMBPAz coating inhibited S.mutans biofilm formation on the PMMA sheets by more than 95%, compared to the uncoated sheets. These findings were also reproduced after being
soaked in water for 1 week.

Objectives: The purpose of this study was to evaluate the association between vascular endothelial growth factor (VEGF) polymorphisms and bisphosphonate-related osteonecrosis of the jaw (BRONJ)
in the Korean population.
Materials and Methods: Forty-five individuals (2 men, 43 women;mean age: 68±12 years) were recruited for the current study. All visited
Yonsei University Dental Hospital for surgical intervention from January
2012 to January 2013 and had a history of bisphosphonate (BP) administration (oral and/or intravenous). Patients were allocated to
BRONJ case (n=26) or control (n=19) groups according to patients’
selection criteria. Association between three VEGF single nucleotide
polymorphisms (rs699947 (-2578 C>A), rs2010963 (-634 G>C) andrs3025039 (+936 C>T)) and BRONJ were investigated using multiple
logistic regression analysis (α = 0.05).
Results: The frequency of CC homozygotes of rs2010963 andrs3025039 of VEGF gene was significantly higher in BRONJ casegroup (p=0.038, 0.026, respectively). Although there was no statistically significant difference in haplotype analysis, the frequency of haplotype C-C (-2578/-634), reconstructed based on LD coefficient values,
was higher among cases (p<=0.126). Extended haplotype C-C-C(-2578/-634/+936) was also more common among cases (p=0.177)
Conclusion: The CC homozygotes of rs2010963 and rs3025039
polymorphism in the VEGF gene was significantly associated with increased risk of BRONJ in Korean population. Further epidemiologicalcohort studies with a larger sample size would be required to confirm
the suggestive correlations.
Keywords: Vascular endothelial growth factor; bisphosphonate;gene polymorphisms; bisphosphonate-related osteonecrosis of thejaw

Conclusion: The PMBPAz coating inhibited plaque accumulation on
the PMMA sheets significantly and showed remarkable resistanceagainst biofilm formation even after soaking stress. These findings
suggest that PMBPAz coating has significant potential to improvehealth in the elderly population by preventing denture plaque-associated infection.
(292word)
Key words: MPC polymer, PMBPAz, PMMA, Biofilm formation, Denture

5. Oral Physiology and Biomechanics

P-26

Withdrawn

P-27
Ultrasonographic observation of masticational
tongue movements in the SDA patient
Masaki Kakudo, Takahiro Fukumoto, Masaki Sato,
Junko Tanaka, Masahiro Tanaka

P-25

Department of Fixed Prosthodontics and Occlusion,
Osaka Dental University

MPC polymer coating inhibits
bacterial plaque on PMMA surface

The purpose of this study was to observe tongue movements during
mastication in patients with short dental arch (SDA).
The subject was a 74 year old female patient with SDA. Tongue
movements during left and right unilateral mastication were examinedby ultrasonography (SSA-250A, Toshiba Medical Systems Corp.).
Waveforms of the tongue movements in M-mode images were classified into the following three stages according to masticating time; initial(chewing immediately after the start of the experiment), middle (period
between the initial and final stages), and final (just before swallowing).
Coronal B-mode images at the lowest points of five consecutive
M-mode waveforms in each stage were traced. Measurement site waspremolars region and molars region. Height differences between theleft and right sides of the tongue were compared between each stage.
The test food was 10 g boiled rice.
In premolars region, the height differences decreased progressively
between each stage in both left and right unilateral mastication. However, in molars region, the height differences did not decreased evenmastication had progressed.
We have studied the tongue movements during mastication in thedentate persons and in the patients with partial teeth loss so far. Height
differences were decreased with mastication progress in the dentate
persons, however that were not decreased in patients without partial

M. Fukunishi1, F. Iwasa1, Y. Inoue3, H. Morisaki2, K. Ikeya1,
N. Takahashi1, K. Ishihara3, H. Kuwata2, K. Baba1
1

Department of Prosthodontics School of Dentistry,
Showa University
2
Department of Oral Microbiology School of Dentistry,
Showa University
3
Department of Bioengineering School of Engineering,
The University of Tokyo
Introduction: The polymer 2-methacryloyloxyethyl phosphorylcholine (MPC) is currently used on medical devices to prevent infection.
Denture plaque-associated infection is regarded as a source of serious
dental and medical complications in the elderly population. Since thesurfaces of acrylic dentures, which are made of polymethyl methacrylate (PMMA), are prone to plaque accumulation, denture hygiene is an
issue of considerable sigbificance for denture wearers.
Objectives: The objective of this study was to investigate the anti-adhesive effects of MPC polymer [poly (MPC-co-BMA-coMPAz); PMBPAz]coating and its durability on PMMA surfaces for the prevention of27

Poster Presentations

The 4-week group has the lowest score.2 Compared with the controls,
Ca2+ contents in experimental group had the higher level except 8
weeks P<0.05 .3 The opening of mitochondrial permeability transitionpore had a higher level on the extraction side than the non-extraction
side and the control group P<0.05 .4 The opening of mitochondrial
permeability transition pore was negatively correlated to mitochondrial
damage index P<0.05 and positively correlated to the Ca2+ content
P<0.05 .Conclusion: The signal way of the mitochondrial permeability
transition pore opening was activated by high concentration of calcium, which may cause the damage of mitochondria and apoptosis.It
may play an important role in the mechanism that hemimastication result in masticatory muscles dysfunction.

dentures. These results were considered that the tongue had to becomplemented the role of residual ridge and teeth by compensatory
movements in SDA patient. These movements were similar to patients’that with partial teeth missing. It was revealed that different tongue
movements were observed in SDA compared with dentate persons.

P-28
Nighttime electromyogram
biofeedback affects physical stress
Taro Mukaibo, Tetsuji Nakamoto, Chihiro Masaki,
Hidetaka Takahashi, Saori Misumi, Yusuke Kondo,
Ryuji Hosokawa

P-30
Oral behaviors and TMD symptoms in
Asian dental students

Department of Oral Reconstruction and Rehabilitation
Kyushu Dental University / Japan

Azusa Kuwashima, Masakazu Ookubo, Yasuhiko Kawai

Sleep bruxism (SB) causes many dental problems such as tooth
wear, muscular pain, implant failure and complications with fixed partial dentures on implants. Although it is an important issue in clinicaldentistry, no reliable treatment has been found so far. In this study, weused electromyogram biofeedback device SleepGurad™, which candetect the SB and notice you with a gentle beep sound to stop the SB,wearing on your forehead. We aimed to study the effect of this biofeedback device against SB and clarify the association between thecontrol of SB and the release of stress. 10 subjects (5 females and 5
males) were participated in this study and crossover design was used.
Sleep measurements were performed for three consecutive nights obtaining data of Baseline without SleepGuard™, with SleepGuard™
beep sound (Group On) and without beep sound (Group Off), datafrom the final day were evaluated. Furthermore, to compare psychological and physical stress before and after sleep, assessments weremade based on STAI-JYZ and the measurement of salivary chromogranin A (CgA) and Cortisol. To compare each parameter among threegroups (Baseline, Group On, Group Off), Friedman’s and Dunn’s tests
were used. As the results, a marked decrease in the number of SB
events per hour were observed in seven subjects in Group On. Moreover, salivary Cortisol concentration after sleep in Group On were significantly higher than that in Group Off. Whereas, Sleep Guard™’s
beep sounds did not affect the percentage of sleep stages, salivary
CgA level, and the Scores of STAI-JYZ. The findings from this study
suggest that biofeedback therapy with beep sound can inhibit SB anddoes not affect sleep quality, however it might increase physical stress.

Nihon University School of Dentistry at Matsudo
Purpose : This study investigated the relation between oral behavior
and TMD symptoms in South Asian and Southeast Asian dental students.
Subjects and Methods : The oral behavior checklist (OBC), symptoms questionnaire of Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and additional questionnaire were administrated to
110 dental students from eight Asian countries (Average age: 21.8 yrs.,
48 males and 62 females) during Asia Pacific Dental Student Association Congress held on 5th August 2014 in Cambodia. Subjects wereallocated into 2 regional groups by their nationality based on United
Nations classification, East Asia (Japan, Taiwan, Hong Kong, andSouth Korea: 41students) and Southeast Asia (Malaysia, Indonesia,
Thailand, and Cambodia: 69students). Logistic regression analysis
was used to analyze items that affect clinical subtype of TMDs (p <0.05).
Results : The prevalence of TMD symptoms: pain, headache, jaw
joint noises, closed locking, and open locking were 40.5%, 16.2%,
36.6%, 17.0%, and 7.3% for East Asia students, and were 39.7%,
48.3%, 24.5%, 4.8% and 4.8% for South East Asia students. Logistic
regression analysis showed that headache was likely affected by "bite,
chew, or play with your tongue, cheeks or lips" (odd ratio (OR) =14.9,
p=0.006), and "chew food on one side only" (OR=7.6, p=0.007). Jaw
joint noise was likely affected by "clench or grind teeth when asleep"(OR=14.3, p=0.012), "sleep in a position that puts pressure on thejaw"(OR=8.5, p=0.002), and "bite, chew, or play with the tongue,
cheeks or lips"(OR=8.1, p=0.027).
Conclusion : This study showed that several sub type of TMD symptoms were significantly affected by some oral behaviors (e.g. Chew
food on one side only etc.).

6. Orofacial Pain and Temporomandibular
Disorders

P-29
Effect of hemimastication on the
mitochondria of rat masticatory muscle

P-31

Xuefen LIN1, Ping JI1,2

Effect of electromyogram biofeedback of
awake-bruxism on sleep-bruxism

1

Dept. of Prosthodontics, College of Stomatology, Shandong University
2
Key Laboratory of Oral Biomedicine of Shandong Province

Naoki Iwase, Masayuki Sato, Hidetoshi Otsuka,
Akira Watanabe, Tomoaki Iizuka, Tomonori Isogai,
Masanori Fujisawa

Objective: The research was designed to study the effect of hemimastication on the mitochondria of rat masticatory muscle.Methods :Mitochondrial damage index were measured by the electron microscope; Ca2+ contents were measured with atomic absorption spectrometry; The mitochondrial permeability transition pore opening was
detected by UV spectrophotometry. Results :1 The mitochondrial damage index score in the extraction side was lower than the non-extraction side, and significantly lower than the control group P<0.01 .

Meikai University
Bruxism is considered to be not only a factor contributing to thedevelopment of temporomandibular disorders, but also a cause of
periodontal tissue destruction, tooth fracture, and damage to dental

28

Poster Presentations

7. Adhesive Dentistry / Dental Materials / Aesthetic
Dentistry

prostheses. Although it is an important problem to resolve in the field ofclinical dentistry, no approaches have been shown to be effective totreat it. This study aimed to examine the effect of electromyogram-biofeedback (EMG-BF) training to improve awake bruxism (AB) on sleep
bruxism (SB).
Twelve male participants (mean age: 26.8 ± 2.5) with subjective
symptoms of AB or a diagnosis of SB were randomly divided into biofeedback (7; BF) and control (5; CO) groups to undergo 5-h EMG measurement during the day and nighttime for 3 consecutive weeks. EMG
electrodes were placed over the temporal muscle on the habituallymasticatory side. The BF group underwent BF training at Week 2,during which a signal was delivered in the event of AB to enhance theirawareness of it. The CO group underwent EMG measurement without
any EMG-BF training within the study period. Subsequently, the number of EMG events exceeding individually assigned threshold values
was calculated, based on the EMG records obtained from measurement.
Although, there were no significant differences between the 2groups at Weeks 1 and 2, a significant decrease in the number of EMG
events was observed in the BF compared to the CO group at Week 3(p < 0.05, Scheffé’s test); in the former, the number of events significantly decreased at Weeks 2 and 3 compared to Week 1 during both
the day and nighttime.
These results suggest the possibility of using EMG-BF training to
improve AB as an effective approach to regulate SB.

P-33
Effect of polishing treatment on
resin bond strength of dentine
Xiangfeng Meng
Department of Prosthodontics,
School of Stomatology, Nanjing University
Objectives
To analyze whether the different surface polishing treatments ofdentin could affect its resin bond.
Methods
Dentin surfaces from non-carious human third molars were divided
into 3 groups. Group A was treated with coarse diamond bur (105125um). Group B was initially polished with fine diamond bur (25um)
following the first step. And group C was fine polished with Sof-Lex
polishing discs after the second step. In each group, samples prepared were bonded with composite resin blocks using self-etch Multilink N/primer A&B (SE) and self-adhesive Multilink Speed (SA). Samples were stored for 24 hours at 37℃ and 100% humidity. And then
their micro-tensile bond strength was tested. The fracture patterns ofsamples were defined.
Results
In SE groups, their bond strength was 72.77±9.20Mpa (group A),
60.78±14.42 Mpa (group B), and 71.26±11.77 Mpa (group C). And in
SA groups, their bond strength was 32.29±7.40 Mpa (group A),
21.89±5.79 Mpa (group B), 36.51±6.26 Mpa (group C). In both groups
SE and SA, the bond strength of group A and group C were significantly higher than group B (p<0.05), and no significant difference wasshown between group A and group C (p>0.05). Most of the fractures
were happened on dentin-cement interface.
Conclusion
Surface polishing treatment could affect the bond strength of dentinwith self-etch and self-adhesive resin cements.

P-32
Analyzing system in biological phenomenausing a portable amplifier
Masaoki Yokoyama, Hiroshi Shiga, Mari Koike
Department of Partial and Complete Denture
Nippon Dental University
The purpose of this study was to develop a biological phenomena
analyzing system using a portable amplifier that would analyze the biological phenomena of a person during sleep at night.
Five healthy subjects and 5 bruxists who has been explained of the
purpose of the experiment were selected as subjects. Using both awireless telemeter system and a portable system, the EEG, EOG, ECG,
masseter muscle EMG, mental muscle EMG were recorded simultaneous throughout the night. Analysis was performed on biological phenomena obtained from wireless telemeter system(NIHON KOHDEN
Co., WEE-6112, WEB-5000) and portable system (S & ME Co., DL3100)
on an arbitrarily selected section. Sleep stages, heart rate, duration ofmasseter muscular activity during bruxism and its cumulative value
were calculated and compared between the two devices.
The values obtained of sleep stages, heart rate, duration of masseter muscular activity during bruxism and its cumulative value of thearbitrarily selected section were very similar for both devices, and no
significant difference was found between the two devices.
From these results it was concluded that the biological phenomena
analyzing system using a portable amplifier has similar precision as
the wireless telemeter system, and thus could be used clinically in analyzing sleep stages, heart rate, duration of masseter muscular activity
during sleep bruxism and its cumulative value.

P-34
The effect of four primers on bonding
strength to zirconia
Lei Chen, Xuehua Deng, Weidan Zhang
Xiangya Hospital of Central South University
Objectives:To evaluate the effect of ceramic primers on bonding
strength between zirconia and composite resin.
Methods:One hundred and ten polished and air-abrased zirconia
blocks were manufactured and divided into ten groups(n=10) according to different ceramic primers and cements:A.No treatment,B.
Z-Prime Plus(Bisco Inc.),C. Rely X Ceramic Primer(3M ESPE.),D.Clearfil Ceramic Primer(Kuraray).E. Monobond-S(Ivoclar Vivadent).Composite resin rods were bonded to the zirconia with Panavia SA Cement(Kuraray) and RelyX Unicem cement(3M).Shear bond streagths ofthe bonded specimens were tested after 37&deg;℃-water storage for24 hours or 2500 thermocyclings(n=5).Failure modes and cement-zirconia bonding interface were observed with scanning electron microscopy(SEM).
Results:According to ANOVA analysis,before and after thermalcycling, group B,C,D,E presented significantly higher SBS(p<0.05) whencompared with group A,the bond strength of groupD was significantly
higher than other groups(p<0.05),but no differences were foundamong the B,C,E groups and between two cements(p>0.05).SEM im-

29

Poster Presentations

ages of the bonding interface showed that Group B,C,D,E resulted in amore tightly bongding than groupA,especially for groupD.
Conclusions:
1. The use of zirconia primers improved the bonding strength between zirconia and resin.
2. 10-MDP-containing primers combined with 10-MDP-containing
cements produce a stronger and more durable zirconia-resin bongding.

burs (carbide burs and diamond points). Materials and Methods: Five
dental ceramics used were IPS e.max Press (Ivoclar Vivadent), IPS e.
max Zir-press (Ivoclar Vivadent), ZENOSTAR (WIELAND Dental +Technik GmbH & Co. KG), P-nano ZR (Panasonic), Fieldspar porcelain(Vintage, Shofu Inc.). Rectangular brocks (3 x 5 x 30 mm; n=10) wereprepared from each ceramics. Two cutting burs employed were diamond point and tungsten carbide bur with same diameter (1.4 mm).
The 3 x 30 mm2 surfaces were cut at a 80gf of weight and a pressureof 200kPa (4.2 x 105 rpm) for air-turbine. Cutting efficiency was evaluated as volume loss from the weight loss cut for 10 s using the densityof each material. The data were statistically analyzed (p<0.05). Results: The cutting volume of Zir-press (1.1 mm3) and Vintage (1.3 mm3)
cut with carbide burs were significantly (p<0.05) higher than those (Zirpress: 0.2 mm3, Vintage: 0.4 mm3) cut with diamond points. The otherceramics (e.max Press, ZENOSTAR and P-nano ZR) had higher cuttingvolume when the diamond points were used. P-nano ZR showed least
cutting volume (< 0.1 mm3) among the ceramics used. Conclusion:
The cutting efficiency of air-turbine burs on P-nano ZR has the least
efficiency among the dental ceramics.

P-35
Investigation of time-dependent wear behavior
of dental ceramics pairing enamel
ShaoFeng Zhang1, JiaWen Guo1, BeiMin Tian1,
Lin He2, Ding Li2
1

State Key Laboratory of Military Stomatology,
Department of Prosthodontics, School of Stomatology,
Fourth Military Medical University
2
State Key Laboratory for Mechanical Behavior ofMaterials, Xi'an Jiaotong University

P-37
Characterization and behaviors of zirconia
discs immersed in simulated body fluid

The excessive abrasion of occlusal surfaces in ceramic crowns limits the service life of restorations and their clinical results. However, little
is known about the time-dependent wear behavior of dental ceramics
when they paired with enamel. The aim of this in vitro study was to investigate the dynamic evolution of wear behavior of two kinds of dental
ceramics when they paired with enamel, as tested in a tribometer.
Specimens were prepared of lithium disilicate and feldspathic porcelain. Isolated cusps of extracted molars were used as antagonists. In
vitro wear was conducted in the tribometer (10 N vertical load) withlubricant (artificial saliva) for 1.2×10^6 cycles. During the testing, several checkpoints were applied to measure the substance loss of theceramics and to evaluate the microstructure of the worn areas. After
1.2×10^6 cycles, the entire wear process of both friction pairs revealed three wear stages (running-in, steady and severe wear stages).
For the friction pair of lithium disilicate: Running-in wear stage
0-8×10^4 cycles; Steady wear stage 8×10^4-1×10^5 cycles; Severe
wear stage 1×10^5-1.2×10^5 cycles. The worn surfaces showed traces of ploughing. For the friction pair of feldspathic porcelain: Running-in wear stage 0-6×10^4 cycles; Steady wear stage 6×10^48×10^4 cycles; Severe wear stage 8×10^4-1.2×10^5 cycles. The
worn surfaces showed traces of intensive wear during the entire wear
process. Comparing the two friction pairs, lithium disilicate showed
more wear loss than feldspathic porcelain. In contrast, the enamel
paired with lithium disilicate showed less volumetric loss. The results
suggest that wear performance of the two friction pairs indicates apparent similarity of the tribological characteristics of the traditional mechanical system. It also exhibited a good correlation among the microstructure and wear loss of worn ceramic. Additionally, the evaluation of
the wear behavior of dental ceramics should be based on these three
wear stages.

Soo-Hyun Kang, Seong-Kyun Kim, Seong-Joo Heo,Jae-Young Koak, Jai-Bong Lee, Jung-Suk Han,
Young-Jun Lim, Sung-Hun Kim, Myung-Joo Kim,
Ho-Beom Kwon, In-sung Yeo, Hong-xuan Quan
Department of Prosthodontics and Dental Research Institute,
College of Dentistry, Seoul National University
Purpose: This study investigated the effect of simulated body fluid(SBF) on hydroxyapatite (HA) precipitation on zirconia discs, and cellproliferation and osteoblast differentiation behaviors on the SBF treated zirconia discs compared with non-treated discs. Materials andMethods: In this study, we made corrected SBF at 36.5 ºC with ion
concentrations nearly equal to those of human blood plasma according to the Kokubo’s recipe. 80 Y2O3-stabilized tetragonal zirconia polycrystals (Y-TZP) discs were prepared and divided into two groups: test
group: SBF treated discs, control group: non-treated discs. Zirconia
discs immersed in SBF for 1, 4, 7 and 14 days in a humidified atmosphere of 95 % air and 5 % CO2 at 37 ºC with initial PH of 7.4. Scanningelectron microscope (SEM) observation was carried out to reveal HA
formation on the discs. Surface structure and composition were characterized by confocal laser scanning microscopy (CLSM), energy dispersive X-ray spectroscopy (EDS) and thin film X-ray diffraction (TFXRD). Moreover, human bone marrow mesenchymal stem cells(hBMMSCs) were used for further evaluating cytocompatibility of the
SBF treated zirconia discs compared with non-treated discs. Cellular
proliferation assay and osteoblast differentiation assay such as Alizarin
Red S staining, ALPase (ALP) staining and ALP activity assay and reverse transcriptase-polymerase chain reaction (RT-PCR) were conducted at different time periods. Results: After soaking different days in
SBF, it showed different surface morphology and with time increasing,
the amount of HA was increased gradually. At day 7, the HA uniformly
covered on the discs, so we used 7 days treated discs as SBF treatedgroup in following research. CLSM showed no difference of surface
roughness between two groups (p>.05). EDS and TF-XRD revealed
vividly that HA formed on the surface after SBF treated. Cell proliferation and differentiation were significantly increased on SBF treateddiscs (p<.05). Conclusions: The data in this study demonstrated that
SBF has the effective role on formation of HA on zirconia discs. The cellattachment, proliferation and differentiation of SBF treated zirconia
discs were comparable to non-treated discs which mean it has thelong term research value.
Key words: zirconia disc, simulated body fluid (SBF), hydroxyapatite(HA), human bone marrow mesenchymal stem cells, cell proliferation,

P-36
Cutting efficiency of air-turbine burson dental ceramics
Ikuya Watanabe, Noriko Nakao, Satoshi Sakoda
Nagasaki University
Objective: The objective of study was to investigate the cutting efficiency of partially stabilized zirconia (PSZ) materials (Y-TZP and CeTZP/Al2</O3 nano-composite) and dental ceramics with air-turbine

30

Poster Presentations

regarding the prosthesis; (iv) no requirement for adjustment of theprosthesis; and (v) at least 6 months experience wearing the prosthesis. From January 2013 to July 2014, a total of 20 maxillectomy patientswere enrolled. Explanatory variables were the number of the maxillaryabutment teeth, occluding units, palatal perforation and soft plate defect. Dependent variable was a*, which is the food mixing ability andobjectively obtained from the chewed color-changeable gum. Multiple
regression analysis with stepwise was used to investigate the factors
affecting a* (SPSS 22, SPSS Japan Inc., Tokyo, Japan). R square as thecoefficient of determination and the adjusted R square value were calculated. (Ethical Committee at Tokyo Medical and Dental University,
Approval No. 865) This work was supported by a JSPS Grand-in-Aid
for Young Scientists (B) (25861828).
Results: P value of the number of the maxillary abutment teeth was
0.813, occluding units was 0.015, palatal perforation was 0.168 andsoft plate defect was 0.536. From stepwise analysis, occluding units
was the only factor affecting masticatory function. The R square was
0.302 and the adjusted R square was 0.261.
Conclusions:
In partial maxillectomy patients, the number of the maxillary abutment teeth would not affect a*. On the other hand, occluding units hada significant effect on a*. In other words, the mandibular teeth condition
would affect the food mixing ability and masticatory function.

osteoblast differentiation.

8. Maxillofacial Prosthodontics and Dysphagia
Rehabilitation

P-38
Effective use of a provisional obturator
prosthesis in edentulous patient
Mamoru Murakami1, Yoshihsa Takenouchi2,
Yasuhiro Nishi3, Masahiro Nishimura3
1

Denture Prosthodontics Restoration, Advanced Dentistry Center,
Kagoshima University Medical and Dental Hospital
2
A-Dental Labo
3
Departments of Oral and Maxillofacial Prosthodontics,
Field of Oral and Maxillofacial Rehabilitation,
Advanced Therapeutic Course, Kagoshima University
Graduate School of Medical and Dental Sciences

We present a simple solution for rehabilitation of an edentulous patient with an extensive maxillary defect. A 70-year-old man in a nursing
home visited our clinic complaining of difficulty chewing and speaking.
Fifteen years earlier, he had undergone maxillectomy to remove a malignant tumor followed by prosthetic treatment at a university hospital inother prefecture. Treatment was discontinued, however, after he moved
from the area. Examination at our institution revealed an edentulous
maxilla with a right maxillary defect. His mandibular dentition consistedof only the right canine and first premolar. Abutment teeth for prostheses were missing, and the soft relining material surrounding the obturator had deteriorated. We diagnosed masticatory dysfunction and articulation disorder due to loss of the abutment teeth and defective
dentures. As there were various problems in the denture components,
we planned to achieve functional recovery by developing a provisional
obturator prosthesis from the old one. It would be used as a template
for a definitive obturator prosthesis after functional recovery. We therefore refurbished the old obturator prosthesis to begin correcting the
problems. After resolution of the chief complaint, we fabricated the definitive prosthesis. We used a dynamic impression technique and amatrix of the polished surface to transfer information from the provisional obturator prosthesis to the definitive prosthesis. We then fabricated a hollow obturator prosthesis and lower partial denture with acast clasp. The results of objective and subjective evaluations for mastication and articulation showed improvement over time, with the highest score recorded at insertion of the definitive obturator prosthesis. As
a result of allowing functional recovery using the provisional obturator
prosthesis and information derived from it for fabricating the definitive
prosthesis, it was possible to obtain an excellent treatment outcome.

P-40
Prosthodontic rehabilitation ofa mandibulectomy patient with
an implant-retained overdenture
Yiliyaer Aimaijiang1, Takafumi Otomaru1,
Yuka Sumita1, Mohamed Said1,
Motohiro Munakata2, Hisashi Taniguchi1
1

Department of Maxillofacial Prosthetics,
Tokyo Medical and Dental University
2
Oral implant center, Department of Prosthodontic Dentistry
for function of TMJ and Occlusion Kanagawa Dental University
A 76-year-old female patient had undergone marginal mandibulectomy due to squamous cell carcinoma and reconstructed with forearm
flap. A mandibular removable partial denture was fabricated. Becauseof caries and root fracture, the right molar was extracted and O-ringattachments (OP anchor attachment) were placed in the anterior residual teeth and a resin based overdenture was fabricated in 2011. In
2013, the overdentrue became unstable because the mobility of one ofthree OP-anchor attachment increased and another was taken off due
to caries. Thus, we planed that two OP anchor attachment would be
extracted and the dental implants were placement to the missing mandibular molar site (non defect side). To compare before and after implant treatment, patient’s perceived chewing ability and oral health-related quality of life (OHRQOL) were evaluated. Patient’s perceived
chewing ability was rated using a food intake questionnaire and Masticatory Score (MS) was obtained. OHRQOL was measured using theGeriatric Oral Health Assessment Index (GOHAI) and GOHAI score
was obtained. The patient agreed with them and two implants (Branemark Mk III) were placed and an implant retained overdenture wasfabricated with stud attachments (Locater). MS was increased from
43% to 61%. GOHAI score was improved to 36 to 51. (Ethical Committee at Tokyo Medical and Dental University, Approval No. 865) This
work was supported by a JSPS Grand-in-Aid for Young Scientists (B)(25861828).

P-39
Investigation of factors affecting food mixing
ability in maxillectomy patients
Takafumi Otomaru, Yiliyaer Aimaijiang,
Mohamed Said, Hisashi Taniguchi
Department of Maxillofacial Prosthetics, Graduate School,
Tokyo Medical and Dental University (TMDU), Tokyo, JAPANPurpose: The purpose of this study was to investigate factors affecting masticatory function in partial maxilletcomy patients with dento-maxillary prosthesis.
Methods: The inclusion criteria for the study were: (i) maxillectomy;(ii) the defect size was less than half; (iii) no complaints by the patient

31

Poster Presentations

tivity is 95 percentage and the specificity is 88 percentage.The result
also showed for this sample that 12 percentage of non-matches could
not be distinguished from the true match, that means there are 12 percentage probability of falsely convicting in an innocent person. Conclusion: This 3D technique allows imagine comparison of a 3D dentition
with a 3D bite mark, eliminats distortion in conventional photograph. So
the 3D technique can be considered a highly accurate method forbitemark analysis.

P-41
Implant supported obturator prosthesis
after partial maxillectomy using
stereolithographic surgical template and
CAD/CAM-milled titanium bar
Kwantae Noh, Janghyun Paek, Ahran Pae,
Hyeong-Seob Kim, Kung-Rock Kwon, Yi-Hyung Woo

P-43

Department of Prosthodontics, School of Dentistry,
Kyung Hee University

The reconstruction of the digital dental
model using grating projection

Extensive surgery for maxillary tumor resection cause severe functional, emotional, and social problems for patients. An obturator prosthesis is the most frequently used treatment option because of thecomplexity of maxillary surgical reconstruction and the uncertainty of
the functional outcome. Lack of support, retention and stability arecommon prosthodontic problems for patients with such defects. If theremaining dentition can’t provide sufficient retention and support, theimplant placement of zygomatic bone can have dramatic effect on thestabiliy and retention of the prosthesis in the maxillectomy patient.
However, implant placement in the zygomatic bone is difficult due toanatomical intricacies of the curved zygomatic bone. The surgery is
not without risk because the drill path is close to critical anatomical
structures in the maxillofacial region. A small angular error may resultin significant positional errors at the end of the tool trajectory. Furthermore, the limited intraoperative visibility, especially given the anatomical intricacies of the curved zygomatic bone, makes this kind of surgery a demanding procedure. Therefore, before zygoma implant
placement, 3D imaging and planning should be performed to ensure
the safety of surgery. Custom-made surgical drilling guides based on
3-dimensional (3D) computerized tomography (CT) scanning has
many advantages in such cases.
This poster presents the implantation using skeletally supported
stereolithographic surgical templates in atrophic zygomatic bone afterpartial maxillectomy and obturator prosthetic rehabilitation using CAD/
CAM-milled titanium bar.

Qin Zhou , Zhenzhen Wang
Stomomatology Hospital of Xi'an Jiaotong University
Objective To lay the foundation for the establishment of digital model database with normal occlusion, the acquisition of digital dental castwith grating projection and the measurement of model features withreverse engineering were used. Methods The grating projection system controlled by a computer was projected onto the surface of normal
dental model. Three-dimensional contour data was obtained bymulti-angle shooting. Three-dimensional model was constructed byusing the grating projection and the model features were analyzed byusing reverse engineering. The digital model compared with the plaster model to detect the consistency which can verify the accuracy ofthe measurement system. Results The structure of three-dimensional
reconstruction model was clear and the system was reliable. The measurement and analysis results with digital model are more accurate bycomparing with plaster model using manual measurement. Conclusion
Reconstruction of digital model by grating projection technique andreverse engineering can be used for dental model measurement inclinical and scientific research, and can provide a scientific method forthe establishment of digital model database with normal occlusion.

P-44

9. Digital Dentistry

Trial for digital fabrication of complete dentures

P-42

Soihiro Hara, Takuya Kobayashi, Yu Yonezawa,
Saori Aki, Hisatomo Kondo

3D imaging and quantitative comparison inhuman bite mark analysis

Department of Prosthodontics and Oral Implantology,
School of Dentistry, Iwate Medical University

Yi Lu, Jun Song
Stomatology Hospital of Xi'an Jiaotong University

Objectives: The development of information technology (IT) and application of CAD/CAM technology has altered the traditional methods
in the dental field. The advanced CAD/CAM technology realized digitallaboratory work with PCs and milling machines after maxillomandibular
registration. However, the impression and the maxillomandibular registration, which are important elements for success of removable denture
treatment, are the toughest step in digital workflow to fablicate the removable prothesis. We have been attempting to make digatal 3-dimensional (3D) model and designed the removable denture without impression materials and stone models. This clinical report introduces anovel technique to make removable dentures.
Materials and Methods:
A subject was an edentulous jaw patient. Digital 3D impression was
performed in which the patient sat in the normal upright position.
During the scanning, buccal muccosa was hold with oa wire retractor
and mucobuccal fold was kept in appropriate shape being dried bysuctioning. Jaw models were created by 3D primter via STL data obtained by the oral scanning. The record base with occlusion rim wasmade on the model. The registration of interocclusal relation was done

Objective: The infliction of a bite is a four dimensional space time
event that is ideally analyzed with three dimensional technology. Comparison of 2D images of a bitemark with a 3D replica of the dentitionof the suspect is challenging. This study presents a technique thatdeveloped for 3D imaging and quantitative comparison in human dentitions and simulated indented bite marks.
Methods: A sample of 63 study models and the corresponding bites
which is made by the universal testing machine in dental wax,they all
digitized by 3D raster scanning. Generate the digital dentition modeland bitemark model using geomagic software. Sign 32 landmarks todescribe the dentitions and bitemarks ,and create a deviation matrix tocompare all possible combinations of matches and non matches. And
then develop a Logistic Regression Model to estimate the probability ofa dentition matching its corresponding bite mark. Results: The effectiveness of the method was analyzed by determining the area underreceiver operating characteristic curve and sensitivity,specificity foreach cut off point. The area under the ROC curve is 0.9763, the sensi-

32

Poster Presentations

according to the conventional method. A result of the registration of
maxillomandibular relation was scanned, reprodeced on CAD software(Dental System, 3Shape), and a removable denture was designed witharrangement of artificial teeth on the PC.
Results: Complete dentures were fabricated without impression materials and sutone models, using oral scanner and CAD softwares.
However, it was difficult to scan the mandiblar muccosa due to its flatten shape, compared to maxilla in which convexity was considerablly
clear. Moreover, it was impossible to determine the border between
alveolar ridge and buccal nuccosa in this impression sytem.
Conclusion: Digital impression system succesfully reproduced both
upper and lower jaws as 3D images although further trials must be required for clinical use.

P-45
3D reproducibility comparison
by restoration type and preparation
location among 5 intraoral scanners:
in-vitro sectional analysis
Rae-Kyeong Nam, Jong-Hun Shin,
Eun-Jin Park, Ji-Man Park
Dept. of Prosthodontics, School of Medicine,
Ewha Womans University
PurposeThe purpose of the study was to evaluate the scanning accuracy
and precision of 5 intraoral scanners by in-vitro sectional analysis
Material and methods
A phantom model having abutments for 3-unit fixed dental prosthesis, MO inlay and single crown was digitized using a reference scanner(Dental Wings 3D scanner) as well as five intraoral scanners (E4D dentist, IOS Fastscan, iTero, Trios, and Zfx intrascan). Datasets obtained
from 4 times scanning of each scanners were loaded into reverse engineering software (Rapidform), superimposed, cross-sectioned andcompared at 4 specific points on 8 sections. One-way analysis of variance (ANOVA) was implemented to compute differences within groups(precision) as well as comparisons with the reference scan (trueness).
A level of statistical significance of p<0.05 was set.
Results
Trueness values ranged from 45.17um (IOS Fastscan) to 114.20um(E4D dentist) and precision ranged from 12.98um (Trios) to 132.33um(Zfx Intrascan). And data anaylsis yield statistically significant differences between IOS Fastscan, iTero, Trios and E4D dentist, Zfx Intrascan.
All intraoral scanners showed similar
trueness values according to preparation location but inferior values atbridge, mesiodistal direction and inlay box. According to the characteristic of intraoral scanners, active triangulation and coating group
showed better performance but there were no significant difference
between still image group and video group.
Conclusion
Significant differences were found among 5 intraoral scanners. And
trueness values could affected by restoration type, scanning technology and necessity of coating. Therefore, dental clinician should consider of this fact when choosing and using an intraoral scanner.

P-46

Withdrawn

33

Author Index
Lin He 
Seong-Joo Heo 
Noriyuki Hoshi 
Ryuji Hosokawa 
Cui Huang 
Dong Neong Huh 
Jung-Bo Huh 
Kim Jee Hwan AYiliyaer Aimaijiang Hitoshi Ajioka 
Saori Aki 
Ryuto Asakawa 
Takashi Asano 
Yasunori Ayukawa 

31
19
32
22
21
13

B
K. Baba 
Min-Hee Ban 

I
27
22

Takashi Iida Tomoaki Iizuka 
K. Ikeya 
Teruo Ino 
Sayumi Inoue 
Y. Inoue 
K. Ishihara 
Tomonori Isogai 
F. Iwasa 
Masatoshi Iwasaki 
Naoki Iwase 
Yoshihiro Iwata C
Lei Chen 
Inho Cho 
H Choi 
Jae-Won Choi 
Sunyoung Choi 21, 29
26
27
16
23

D
Xuehua Deng 

Kyoung-Bae Jeon Young-Chan Jeon 
Chang-Mo Jeong Ping JI 
Xinquan Jiang 
Han-Sung Joo 
Jung Hyun Jung 

E
7
17
22

F
Jiangyuan Fan 
Jocelyne Feine 
Masanori Fujisawa 
Shota Fukazawa 
Takahiro Fukumoto 
M. Fukunishi 

Masaki Kakudo 
Hye-Won Kang 
Soo-Hyun Kang Yasuhiko Kawai Misao Kawara 
Ah-Rang Kim 
Eunkyung Kim 
Hyeong-Seob Kim 
Hyunyoung Kim 
Jee-Hwan Kim 
J-H Kim 
Myung Joo Kim 
Seong-Kyun Kim 
Su-Min Kim 
Sung-Hun Kim 
Tae-Kyun Kim 
TH Kim 
Katsuhiko Kimoto 
Jae-Young Koak 
Takuya Kobayashi 
Naoki Kodama 

G
21
24
30
26

H
Jung-Suk Han 
Soihiro Hara 
Yoshiya Hashimoto 

24
16, 18, 20
16, 18, 20
28
14
22
25

K
19
19
22, 2819
27
27

Shanshan Gao 
Tomoya Gonda 
JiaWen Guo Song Young Gyun 

21, 2228
27
22
21, 2227
27
22, 28
27
21
28
21

J

29

Hiroshi Egusa Elham Emami 
Satoshi Endo 

30
15, 23, 30
18
28
25
16
16, 18, 20
25

23, 30
32
26

34

27
20
30
19, 2821, 2216
26
12, 3226
23
27
23, 3023, 3016
23, 3024
27
18
23, 3032
17Mari Koike 
Satoshi Komasa 
Osamu Komiyama 
Yoshihiro Komoda 
Hisatomo Kondo 
Yusuke Kondo 
Toshikazu Kuroki Tetsuji Kusumoto 
Azusa Kuwashima 
H. Kuwata 
Ho-Beom Kwon 
Kung-Rock Kwon 

Noriko Nakao 
Rae-Kyeong Nam 
Se-Jin Nam 
Yasuhiro Nishi Masahiro Nishimura 
Hiroshi Nishizaki 
Toshifumi Nogawa 
Kwantae Noh 
Hiromasa Noro 29
26
10, 21, 22
21
19, 32
28
22
26
28
27
23, 3032

O
Chikayuki Odaira 
Sang-min Oh 
Joji Okazaki 
Masakazu Ookubo Takafumi Otomaru 
Hidetoshi Otsuka LDu-Hyeong Lee 
Jae-Hoon Lee 
Jai-Bong Lee 
Jung-Wha Lee 
Kyu-Bok Lee 
So-Hyoun Lee 
Ding Li 
Xing Liang 
Jian Liao 
Yunmao Liao 
Hyun-Pil Lim 
Young-Jun Lim 
Tingting Lin 
Xuefen LIN 
Siying Liu 
Yang Liu 
Yi Lu 

30
33
20
31
31
26
24
32
22

20, 24
9, 27
23, 30
26
24
20
30
25
25
25
22
30
19
28
25
21
32

19
25
26
28
31
28

P
Ahran Pae 
Janghyun Paek 
Do-Hyeon Park 
Eun-Jin Park 
Ji-Man Park Jung-Wan Park 
Sang-Won Park 
Seong Jae Park 

32
32
16
33
33
24
22
16

Q
Hong-xuan Quan M
Jianfeng Ma 
Yoshinobu Maeda 
Yixin Mao 
Chihiro Masaki Manabu Masuda Takashi Matsuura 
Xiangfeng Meng 
Jie Min 
Shogo Minagi 
Saori Misumi Akiko Miyake 
Emiri Mizumachi 
Yoko Mizuno 
H. Morisaki 
Taro Mukaibo Motohiro Munakata Hiroshi Murakami Mamoru Murakami 

19
24
19
28
22
24
29
21
17
28
26
24
24
27
28
31
19
31

S
Mohamed Said 
Makiko Saita 
Satoshi Sakoda Michiko Sasaki 
Hironobu Sato 
Masaki Sato 
Masayuki Sato 
Lee Joon Seok 
Cetin Sevük 
Hiroshi Shiga 
Jong-Hun Shin Young-Gun Shin 
Yosuke Shinozaki 
Fangfang Song 
Jun Song Masahiro Sugimoto 
Yuka Sumita 
Hiroshi Suzuki NTetsuji Nakamoto 

30

28

35

31
18
30
24
24
27
28
26
6
29
33
18
24
25
32
18
31
22

Ruibin Zheng 
Qin Zhou 
Yi Zhou 
Yongsheng Zhou TYoichiro Taguchi 
Yu Takaesu 
Hidetaka Takahashi Kazuya Takahashi 
N. Takahashi 
Toshihito Takahashi 
Yoshiaki Takanashi 
Yoshiyuki Takayama 
Yoshihisa Takenouchi Junko Tanaka Masahiro Tanaka Hisashi Taniguchi Yuichiro Tashiro 
Daisuke Teshigawara 
BeiMin Tian 
Akiko Tomita 

26
24
28
26
27
24
19
17, 24
31
27
27
31
26
22
30
24

V
Mong-Sook Vang 

22W
Jiawei Wang 
Siqian Wang 
Xiaoqi Wang 
Yining Wang Yong Wang Zhenzhen Wang Akira Watanabe 
Ikuya Watanabe 
Yi-Hyung Woo 

17
19
18
17
25
32
28
30
32

Y
Hong-So Yang 
Hongye Yang 
Jian Yang In-sung Yeo 
Soo-Hyun Yim 
Atsuro Yokoyama Masaoki Yokoyama 
Yu Yonezawa 
Masazumi Yoshitani 
Dandan Yu 
Haiyang Yu 
Jiaxi Yue 
Kwi-Dug Yun 
Mi-Jeong Yun 

22
25
16
23, 3023
17, 2429
32
17
21
11, 2125
22
16, 18, 20

Z
ShaoFeng Zhang 
Weidan Zhang 30
21, 2936

19
32
17, 188, 16

“Biologic conyribution in theprosthodontic research”

CORPORATE SPONSORSThe Organizing Committee wishes to thank the following companies for their generous support for the2015 Biennial Joint Congress of Japan Prosthodontic Society, Chinese Prosthodontic Society, andKorean Academy of Prosthodontics.

⃝Sponsors
・3M ESPE・Sun Medical Co., LTD.

⃝Advertisers
・Sun Medical Co., Ltd.
・GC CORPORATION
・Wada Precision Dental Laboratories Co., Ltd.
・J. MORITA CORPORATION
・SHOFU Inc.
・Tokuyama Dental Corporation Inc.
・3M Health Care Ltd.
・KaVo Dental Systems Japan Co., Ltd.
・OSADA ELECTRIC C0., Ltd.

⃝Exhibitor
・Sun Medical Co., Ltd.

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