The Use of Intraoral Imaging at Clinical Crown Lengthening Procedures
Phase: NA
Conditions: Dental Caries of Root Surface, Surgery
Sponsor: University of Maryland, Baltimore

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Cover Page 
 
Official Title of the Study: 
 
The Use of Intraoral Imaging at Clinical Crown Lengthening Procedures 
 
NCT number: 
 
NCT03064217 
 
Date of the Document: 
 
February 11, 2022 
 

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Project Summary 
 
Crown lengthening surgery is done when a tooth needs to be fixed with a crown. Sometimes, not enough of the 
tooth sticks out above the gum to support a crown. This can happen when a tooth breaks off at the gum line, or 
when a crown or filling falls out of a tooth and there is decay underneath. To place a crown, the dentist needs 
to expose more of the tooth. This is done by removing some gum tissue or bone. After surgery, the area will 
heal in about three months. Then, making a crown can begin. This healing period often delays the delivery a 
final crown. This study is investing a way to make the final impression at the surgery to expedite the delivery of 
a final crown. 
 
General information 
 
Title: The Use of Intraoral Imaging at Clinical Crown Lengthening Procedures 
 
Funding Information 
 
1. The department of Endodontics, Periodontics, and Prosthodontics (EPP) and the department of General 
Dentistry will partially support this study regarding supplies for procedures and participant compensation. The 
ADEA project pool fund will also partially support this study. 
 
2. The American Dental Education Association 
655 K Street NW, Suite 800 
Washington DC, 20001, USA 
 
The Principal Investigator 
 
Se-Lim Oh, DMD, MS 
Clinical Associate Professor 
Division of Periodontics 
University of Maryland School of Dentistry 
 
650 West Baltimore Street, Room 4211 
Baltimore, MD 21201 
 
Office phone) 410-706-8061 
Email: soh@umaryland.edu 
 
Resources 
 
The Principal Investigator is devoting 10% of her time to conducting and completing the research. There is 
sufficient time to conduct, oversee and complete research. Patients will have enough time to ask questions and 
to address their concerns before they participate in this research. Enough clinical times are allocated for each 
participant to conduct the procedures described in this protocol. A research coordinator and a certified dental 
assistant are working with the PI and research team members. All procedures in this protocol are performed 
with the separate room to secure the information. The University of Maryland School of Dentistry (UMSOD) is 
currently having many patients on its records. In addition, there are at least seven new patients to visit the 
clinics in each clinic session. All research team members completed CITI and HIPAA trainings. The research 
team members are responsible to recruit subjects. The PI and the research team members will perform all 
surgical procedures described in this protocol. 
 
Sites where research activities will be conducted 
 
This is a single site study. The study will be conducted at the UMSOD dental clinics. 
650 West Baltimore Street, Baltimore, MD, 21201, USA 

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Clinical Trial Registration: NCT03064217 
 
Rationale and background information 
 
Dental caries is the most common oral disease, which affects the crown and/or the root surfaces of teeth. The 
prevalence of dental caries in permanent teeth among adults 20-64 years of age was approximately 92% 
during 1999-2004.1 Overall root caries experience was 36% among the adult population.1 When dental caries 
affects most tooth surfaces, a crown is recommended to protect the tooth. In cases that caries extends below 
the gingival margin, a clinical crown lengthening procedure (CLP), “a surgical procedure designed to increase 
the extent of supragingival tooth structure for restorative or esthetic purposes by apically positioning the 
gingival margin, removing supporting bone, or both”2, is often required to fabricate a crown. 
 
The conventional treatment protocol involving a CLP is as follows; 1) caries control with core build-up, 2) initial 
tooth preparation, 3) performing a CLP, and 4) making the final impression with elastomers using double 
gingival cords, and 5) delivering a crown. A healing period of 6 to 12 weeks after CLPs is recommended.3, 4 
Since packing two gingival cords could injure the soft tissue still in healing and the tooth preparation was not 
definitive at a CLP, the restorative treatment is generally initiated 3 months after CLPs. However, this waiting 
period delays the final crown delivery, which is often patient’s chief complaint. 
 
The technical developments have brought digital workflows, such as computer aided design/computer aided 
manufacturing (CAD/CAM) and intraoral imaging, to restorative dentistry. This technique allows fabricating the 
fixed restoration without taking impression via impression materials. Studies reported that digital impressions 
were equally or more accurate and precise than plaster models made by impression materials.5-7 
 
Since intraoral imaging system allows us to take the impression without applying impression materials around 
teeth, the final impression could be made at the surgery without increasing any postoperative complications. If 
the final tooth preparation could be made at the surgery and making the final impression are performed at a 
CLP, a delivery of the final crown can be expedited. 
 
Several studies5-8 have reported the benefits of chairside intraoral imaging system and CAD/CAM from patient- 
centered outcomes and from technical and economic aspects. However, the use of intraoral imaging in 
conjunction with CLPs has not been examined. Furthermore, there is no systematic study investigating the 
influences of final prostheses on the soft tissue and the hard tissue around teeth when they are delivered 
before the 8 to 12 weeks healing period after CLPs. 
 
Study goals and objectives 
 
The purpose of this study is to evaluate clinical and radiographic outcomes of single unsplinted fixed 
restorations made with digital intraoral imaging in conjunction with CLPs, compared ones fabricated with digital 
intraoral imaging made at 8 to 12 weeks following CLPs. 
 
Specific Aim 1: To evaluate the clinical outcomes between the experimental group (the digital impression 
taking at CLPs) and the control group (the digital impression taking at 12 weeks following CLPs) 
Hypothesis: There will be no differences in clinical parameters around the teeth between the two groups. 
Approach: We will conduct a prospective clinical study and will compare the changes in gingival recession, the 
width of keratinized gingiva, and pocket depths around the teeth between the two groups. 
 
Specific Aim 2: To evaluate the radiographic outcome between the experimental group and the control group 
Hypothesis: There will be no difference in crestal bone level around teeth between the two groups. 
Approach: The study will investigate the difference in crestal bone level around the teeth at baseline and 12 
months between the two groups. 

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The results from this study would give a better prediction of the healing after CLPs and scientific supports for 
making the final impression at the surgery to expedite the delivery of final prostheses. Thus, this study will 
achieve a sustainable impact on the interdisciplinary field, both periodontics and restorative dentistry. 
 
Literature review 
 
The biologic width around teeth includes both connective tissue and junctional epithelium attachment. Its 
average dimension is 2 mm, and it presents in all healthy dentitions.9 Invasion of the biologic width with a 
restoration could result in crestal bone loss and persistent gingival inflammation.10 Thus, a clinical crown 
lengthening procedure (CLP) is often required to treat a caries extended below the gingival margin. The 
apically positioned flap with osseous surgery is the most common procedure for CLPs. A few studies 
investigated healing after CLPs. Crown length gained from CLPs was significantly decreased at 6 months.11 
The coronal displacement of the gingival margin was observed during 12 months period of healing following 
CLPs.12, 13 
 
The waiting period before initiating restorative procedures is still controversial.14 Wagenberg et al.15 
recommended 12 weeks. Two to four mm of gingival recess was reported between 6 weeks and 6 months 
postoperatively.3 The original biologic width was reestablished by 3 months.4, 16 Therefore, a wide range from 6 
weeks up to 6 months was recommended by literature based on the soft tissue healing. 
 
However, beginning restorative procedures should not be predominantly based on the timing of restoring the 
biologic width only, since a long-term use of a temporary crown is not recommended. In fact, the dimension of 
biologic width is different from surface to surface even in the same tooth.10 Therefore, another controversial 
issue regarding CLPs is the amount of bone reduction. Based on the concept of the biologic width, there is a 
necessary amount of root surface to be exposed for restoring this dimension. However, a limitation of bone 
reduction also exists due to the local anatomical factor, such as the furcation, and a crown to root ratio. Dibart 
et al.17 reported that 40% of the mandibular molars developed a furcation involvement at 5 years after CLPs 
and the final crown delivery. Meanwhile, Diniz et al. reported no significant changes in the crestal bone level 
during 12 months period after removal of crestal bone at CLPs.18 In summary, there is a little consensus among 
studies regarding the post-surgical changes following CLPs. The optimal timing of restorative treatments has 
not been systemically investigated. 
 
References 
 
1. Dye BA, Tan S, Smith V, et al. Trends in oral health status: United States, 1988-1994 and 1999-2004. Vital 
Health Stat 11. 2007;(248):1-92. 
2. Glossary of Periodontal Terms. American Academy of Periodontology 2001. 
3. Bragger U, Lauchenauer D, Lang NP. Surgical lengthening of the clinical crown. J Clin Periodontol. 
1992;19:58-63. 
4. Lanning SK, Waldrop TC, Gunsolley JC, Maynard JG. Surgical crown lengthening: evaluation of the 
biological width. J Periodontol. 2003;74:468-474. 
5. Henkel GL. A comparison of fixed prostheses generated from conventional vs digitally scanned dental 
impressions. Compen Contin Educ Dent. 2007;28:422-4, 426-8, 430-1 
6. Syrek A, Reich G, Ranftl D, Klein C, Cherry B, Brodesser J. Clinical evaluation of all-ceramic crowns 
fabricated from intraoral digital impressions based on the principle of active wave front sampling. J Dent. 
2010;38:553-559. 
7. EnderA, Mehl A. Full arth scans: conventional versus digital impression—an in-vitro study. Int J Comput 
Dent. 2011;14:11-21 
8. Christensen GJ. The state of fixed prosthodontic impressions: room for improvement. J Am Dent Assoc. 
2005;136:343-346. 
9. Vacek JS, Gher ME, Assad DA, Richardson AC, Giambarresi LI. The dimensions of the human 
dentogingival junction. Int J Periodontics Restorative Dent. 1994;14:154-165. 
10. de Waal H, Castellucci G. The importance of restorative margin placement to the biologic width and 
periodontal health. Part I. Int J Periodontics Restorative Dent. 1993;13:461-471. 

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11. Arora R, Narula SC, Sharma RK, Tewari S. Evaluation of supracrestal gingival tissue after surgical crown 
lengthening: a 6-month clinical study. J Periodontol. 2013;84:934-940. 
12. Pontoriero R, Carnevale G. Surgical crown lengthening: a 12-month clinical wound healing study. J 
Periodontol. 2001;72:841-848. 
13. Deas DE, Moritz AJ, McDonnell HT, Powell CA, Mealey BL. Osseous surgery for crown lengthening: a 6- 
month clinical study. J Periodontol. 2004;75:1288-1294. 
14. Pilalas I, Tsalikis L, Tatakis DN. Pre-restorative crown lengthening surgery outcomes: a  systematic 
review. J Clin Periodontol. 2016;43:1094-1108. 
15. Wagenberg BD, Eskow RN, Langer B. Exposing adequate tooth structure for restorative dentistry. Int J 
Periodontics Restorative Dent. 1989;9:322-331. 
16. Ganji KK, Patil VA, John J. A Comparative Evaluation for Biologic Width following Surgical Crown 
Lengthening Using Gingivectomy and Ostectomy Procedure. Int J Dent. 2012;2012:479241. 
17. Dibart S, Capri D, Kachouh I, Van Dyke T, Nunn ME. Crown lengthening in mandibular molars: a 5-year 
retrospective radiographic analysis. J Periodontol. 2003;74:815-821. 
18. Diniz DE, Okuda KM, Fonseca CR, et al. Surgical crown lengthening: a 12-month study - radiographic 
results. J Appl Oral Sci. 2007;15:280-284. 
 
 
Preliminary findings 
We have performed several cases, in which final impressions were made during crown lengthening procedures 
(CLPs) and final crowns were delivered at suture removal appointments and have observed favorable 
outcomes including shortening overall treatment time, reducing visits, no postoperative pain, and no crestal 
bone loss from the previous cases. 
Figure 1 depicts one of our 
previous cases. A delivery of a 
final gold crown for #19 was 
planned. However, the crown 
margin was still on a core 
material evident on a bitewing 
radiograph (Fig. 1a). Therefore, 
a CLP was recommended to re- 
prepare the tooth and to place 
the crown margin on the sound 
tooth structure. At the CLP, 
buccal and lingual full thickness 
flaps were retracted and the 
surrounding    soft    tissue   was 
removed   (Fig.   1b)   so   that a 
restorative dentist was able to 
complete the tooth preparation. 
The final impression was made 
with 
Omnicam® 
(Fig. 
1c). 
Osseous 
surgery 
was 
completed and sutures were 
placed (Fig. 1d). A temporary 
Figure 1. #19 gold crown fabricated with digital impression made during a CLP. (a) 
Delivery of a final crown was attempted but was not successful because the crown 
margin was still on a core. (b) Full thickness flaps were retracted during the CLP. Final 
preparation was performed. (c) Final impression was made with Omnicam®. (d) Sutures 
were placed to complete the surgery. (e) The final crown was delivered at 2 weeks after 
the surgery. (f) A bite-wing confirmed the fitting of crown margin. 
crown was cemented and Coe-pakTM was placed. No antibiotics were prescribed and over-the-counter 
ibuprofen was recommended for pain management. A final gold crown was delivered at 2 weeks following the 
surgery at the suture removal appointment (Fig. 1e). A postoperative radiograph confirmed the fitting of crown 
and the crown margin was placed on the sound tooth structure (Fig. 1f). This patient only took one 200 mg 
ibuprofen right after the CLP and did not experience any pain or any discomfort either after the CLP or after the 
delivery of the final crown. 
The University of Maryland School of Dentistry (UMSOD) is now fully equipped with intraoral imaging and 
CAD/CAM (computer aided design/computer aided manufacturing) systems. A lithium disilicate crown can be 

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fabricated in house laboratory. Therefore, we are fabricating and delivering lithium disilicate crowns as final 
restorations in our study. 
 
Study design 
 
This 
is 
a 
prospective 
randomized 
controlled trial (RCT) to investigate the 
clinical and radiographic outcomes of 
lithium disilicate crowns made by digital 
technology 
following 
clinical 
crown 
lengthening procedures (CLPs). Figure 
2 shows a flowchart of the study. The 
final 
preparation 
and 
the 
final  
impression are made at the CLP in the 
experimental group; the final preparation 
and the final impression are made after 
8 weeks following the CLP in the control 
group. After the delivery of lithium 
disilicate crowns, all subjects will be 
followed at 12 months to perform 
periodic evaluation and oral prophylaxis. 
 
Methodology 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 2. A flowchart of study. 
1) The Study population: the groups to be recruited are patients registered in dental clinics at the UMSOD. 
Twenty subjects will be enrolled; the subjects will be randomly assigned to the experimental group (10 subjects) 
or to the control group (10 subjects) using a random number table. Subjects with the following conditions will  
be included: a) age >18 years, b) a single-unsplinted crown needed, c) a tooth must be in the area from the 
canine to the second molars, d) a CLP is required to fabricate a lithium disilicate crown. Exclusion criteria are  
as follows: a) uncontrolled hypertension, b) diabetes mellitus patients whose HbA1c level is 6.5% and above, c) 
subjects with a history of a long-term use of corticosteroid (> 6 months), d) subjects with a history of taking 
oral/IV bisphosphonates within the past 2 years, e) subjects taking anticoagulants, and f) smokers. 
At the enrollment, if potential subjects are diabetic, the potential subjects are required to provide their A1c level 
verified by their primary care providers. The A1c level accepted needs to be within 3 months. 
2) Clinical measurements: A Williams probe (Hu-Friedy) will be used to obtain the level of gingival margin 
(GM), the width of keratinized gingiva (KG), and pocket depths (PDs). 
The following measurements will be obtained at delivery of the crown. 
a) Gingival Margin (GM) will be measured from the cervical margin of the crown to the free gingival margin at 
the facial and lingual/palatal sites. 
b) The width of keratinized gingiva (KG) will be measured from the free gingival margin to the mucogingival 
junction (MGJ) at the midfacial and the midlingual surfaces. The MGJ will be identified by the color contrast 
between gingiva (pink) and mucosa (red). 
The following measurements will be obtained at 12-month follow-up. 
a) Gingival Margin, b) The width of KG, c) Probing depths 
3) Clinical photographs will be taken at each appointment. Obtaining intraoral photographs is the standard 
way to compare before and after the treatments. 
 
4) Radiographic measurements: the radiographs will be exposed at baseline (the delivery of final prostheses; 
T0) and 12-months follow-up (T12). A blind evaluator will measure crestal bone loss from the crown margin to 
the most coronal aspect of the alveolar crest at the mesial and distal sides of the teeth on the bitewing 
radiographs. MiPACS® distal radiography system will be used to measure crestal bone level. 

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5) All procedures being performed for research purposes only 
All procedures being performed in this research (except obtaining signatures on the consent form) would need 
to be done for those patients regardless of their participation in this study. 
 
The clinical photographs will be taken at the evaluation appointments and scanning with intraoral imaging will 
be obtained for the final impression. Obtaining the intraoral images is the standard way to compare before and 
after the treatments. All procedures described in the protocol are in accordance with the standard protocol for 
each treatment. 
 
The final impression will be made with intraoral imaging (intraoral camera) in both groups (the experimental 
group and the control group). 
 
Two diagnostic radiographs need to be made in both groups (the experimental and the control group) at 
delivery of crown and 12 months follow-up. No additional x-ray in the control group will be exposed. The fees 
for radiographs are included in the crown delivery and in periodic oral evaluation. Therefore, no additional fees 
will be charged. 
 
The following procedures are research procedures. 
1) If potential subjects are diabetic from medical history taking, the potential subjects are required to verify their 
HbA1c levels confirmed by their primary care providers. The A1c level accepted needs to be within 3 months. 
2) Obtaining signatures on the consent form at screening visit in the experimental and the control group. 
The PI and/or research team members will follow the protocol in the approved IRB application while we are 
obtaining signatures from the potential subject. The information will be given to the potential subject in the 
separate room. The potential subject will be encouraged to ask the PI and/or research team members any 
questions regarding this protocol. 
3) The final impression made with intraoral imaging system at the surgery in the experimental group 
This is a research procedure. Since intraoral imaging system allows us to take the impression without applying 
impression materials around teeth (in the mouth), the final impression could be made at the surgery without 
increasing any postoperative complications. No materials will be contacting the flap and the tooth. The PI and 
research team members are experienced dental providers and will carefully monitor subjects. 
 
6) The duration of an individual participant’s participation in the study 
An individual participant is expected to present from 7 to 10 appointments to complete his/her participation. 
The anticipated duration for an individual participant is approximately 18 months. 
 
7) The research procedures at each appointment for the experimental group are as follows: 
a) Appointment 1 (30-40 iminutes): A screening visit. Clinical examination and taking clinical photographs 
will be done. 
b) Appointment 2 (60-90 iminutes): Cavity removal, filling and initial tooth preparation will be performed 
under local anesthesia. 
c) Appointment 3 (120 iminutes): A clinical crown lengthening under local anesthesia will be performed. 
The final impression will be made with introral imaging (intraoral camera) at surgery. 
d) Appointment 4(60-120 iminutes): Suture removal and a final crown delivery 2 weeks after the surgery 
will be performed. X-rays will be taken to veryify the fitting of a crown. 
e) Appointment 5 (30 iminutes): Examination of bite and gum tissue 4 weeks after the delivery of a crown. 
f) Appointment 6 (40-60 iminutes): 6 months after the crown delivery. Examination and cleaning will be 
performed. 
g) Appointment 7 (40-60 iminutes): 12 months after the crown delivery. Examination, taking x-rays, and 
cleaning will be performed. 
 
8) The research procedures at each appointment for the control group are as follows: 
a) Appointment 1 (30-40 iminutes): A screening visit. Clinical examination and taking clinical photographs 
will be done. 
b) Appointment 2 (60-90 iminutes): Cavity removal, filling and initial tooth preparation will be performed 
under local anesthesia. 

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c) Appointment 3 (120 iminutes): A clinical crown lengthening under local anesthesia will be performed. 
d) Applintment 4 (30 minutes): Suture removal and postoperative follow-up 
e) Apppointment 5 (30 minutes): Evaluation of gume tissue 4 weeks after the surgery 
f) Appointment 6 (60-120 minutes): The final impression will be made with intraoral imaging (intraoral 
camera) at surgery 8 to 12 weeks after the surgery. 
g) d) Appointment 7(60-120 iminutes): A final crown delivery. X-rays will be taken to veryify the fitting of a 
crown. 
h) e) Appointment 8 (30 iminutes): Examination of bite and gum tissue 4 weeks after the delivery of a 
crown. 
i) 
Appointment 9 (40-60 iminutes): 6 months after the crown delivery. Examination and cleaning will be 
performed. 
j) 
Appointment 10 (40-60 iminutes): 12 months after the crown delivery. Examination, taking x-rays, and 
cleaning will be performed. 
* All procedures described above are in accordance with the standard protocol for each procedure. 
 
9) Audio or Video Recording/Photographs 
 
1. What is the purpose of the recording 
1) To make digital dental impression for fabricating the final crowns 
2) To compare clinical parameters (such as gingival recession or keratinized gingiva) before, during, and 
after treatments 
 
2. How will individuals' identities be protected? 
The facial photography will not be made. Only intraoral dental images will be made. The digital impression can 
be stored only in the specific software that is password-protected. Intraoral photographs made by the 
investigators will be stored in the computer at the room 4211. The computer in the room 4211 is password- 
protected. The room 4211 will be locked at the end of the day. The photographs might be on the publication. 
However, no individual identification will be attached. 
 
Safety considerations 
 
1. Potential risks related to the study 
 
Taking part in this study will expose participants to some potential risks from what they would have from 
routine crown lengthening surgery and crown placement. 
 
Risks from gum surgery and crown placement in both groups: 
• There might be bleeding after the surgery. Pressure dressing will be used to prevent bleeding. 
• There might be some pain after the surgery. Pain medicine will be prescribed. 
• Infection rarely occurs after the gum surgery. However, if infection develops, an antibiotic will be prescribed. 
• You may feel some discomfort after the procedures. This discomfort will subside within two weeks. 
• The crown may or may not need adjustments in both groups. 
• The gum receding may or may not occur after the crown delivery in both groups. 
 
Risks for the subjects assigned to the experimental group. 
• There is a chance it might not be as successful as standard of care. 
 
There is a potential for breach of confidentiality in both groups. Research data will be kept in a file cabinet in 
room 4211 at the UMSOD. The room 4211 will be locked at the end of each day. Only research team members 
listed on the protocol will have access to research data. 
 
2. Potential benefits related to the study 

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The subjects may or may not get any benefits from participating in this study. They will receive the dental 
treatments that are indicated. The subjects assigned to the experimental group will get a crown earlier. 
The results from this study would give a better prediction of the healing after CLPs and scientific supports for 
making the final impression at the surgery to expedite the delivery of final prostheses. Thus, this study will 
achieve a sustainable impact on the interdisciplinary field, both periodontics and restorative dentistry. 
The surgical procedures and the dental restorative procedures in this study are in accordance with standard 
periodontal surgical procedures and standard restorative procedures. No more additional risk is encountered 
than at routine dental visits for periodontal surgery and restorative procedures. The PI and research team 
members will closely monitor all subjects in this study. 
Participation is voluntary and the alternative is not to participate. 
Follow-up 
 
The study aims to follow participants up to 12 months after the delivery of the final crowns. Periodic oral 
evaluation, obtaining x-rays, and oral prophylaxis will be performed. 
 
Data management and Statistical Analyses 
 
1) Sample Size Determination 
This study is the first clinical trial to determine the feasibility and safety of the proposed approach. Therefore, 
10 subjects in each group are selected as a pilot study to clarify whether making the final impression at the 
surgery is acceptable or not. 
 
2) Calibration for the Evaluator 
SO will calibrate one investigator in terms of obtaining clinical parameters and radiographic crestal bone levels. 
SO and one investigator will measure GR, KG, PDs, BOP, and crestal bone levels and record Plaque Index 
separately for 10 patients. Pearson correlation coefficient (r) will be used to test the reliability. 
 
3) Data Analysis: Descriptive statistics will be prepared for all outcome variables (mean ± standard deviation). 
To test the null hypothesis of no difference in level of GM, PDs and CBLs at each time point between the 
experimental and control groups, independent t-tests will be conducted. The confidence interval (CI) of the 
treatment difference in crestal bone loss between the two groups will be evaluated against the non-inferiority 
margin (0.5 mm). A p ≤ 0.05 will be considered significant. 
 
Recruitment 
 
The research team members will recruit potential subjects through patients’ screening, regular dental visits, 
and recall examinations. After the approval from IRB, the PI will present the brief summary of the study to the 
dental providers at the UMSOD. Dental providers who find a potential participant will introduce the study to a 
potential participant and will give the contact information to one of research team members upon patient’s 
agreement. The PI and the research team members will ensure that all potential participants have a chance to 
talk and ask questions any time. The PI and the research team members will be sensitive to any signs of 
distress on the part of the participants. Individuals who refuse to participate will not be penalized in any way. 
 
Eligibility Checklist 
 
Inclusion/Exclusion Criteria (once the protocol is approved, this page must be copied, used as a checklist for 
screening subjects, signed by investigator, and inserted in research record for every subject screened): 
Inclusion Criteria 
 
Yes No Criteria 
. 

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□ 
□ 
age >18 years 
□ 
□ 
a single-unsplinted crown needed 
□ 
□ 
the tooth must be in the area from the canine to the second molar 
□ 
□ 
a CLP (crown lengthening procedure) is required to fabricate a crown 
 
 
Exclusion Criteria 
 
Yes 
No 
Criteria 
. 
□ 
□ 
uncontrolled hypertension 
□ 
□ 
diabetes mellitus patients with whose HbA1c level is 6.5% and above 
□ 
□ 
subjects with a history of a long-term use of corticosteroid (> 6 months) 
□ 
□ 
subjects with a history of taking oral/IV bisphosphonates within the past 2 years 
□ 
□ 
smokers 
 
 
Quality assurance 
 
Se-Lim Oh and Radi Masri perform quality monitoring. Se-Lim Oh is the principle investigator of the study. 
Radi Masri is not a research team member. He has conducted several clinical trials at the UMSOD. 
 
The final DSMB report is attached (Appendix 1). 
 
Expected outcomes of the study 
 
Making the final tooth preparation and the final impression at CLP will significantly reduce the time between the 
CLP and the delivery of the final crown and show comparable clinical outcomes. 
 
Dissemination of results and publication policy 
 
Research data will be kept storing in a file cabinet in a locked office (4211). Only research team members in 
this study will have access to the research data. The data from the study may be published. However, the 
subjects will not be identified by their names. The personal information will not be given out unless required by 
law. 
 
Duration of the project 
 
This study will last about 3 years 
 
Table 1. Study Period-Timetable for Completion of the Project 
 
Research 
procedures 
2 months 
18 months 
30 months 
36 months 
Calibration 
 

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Recruitments 
The 
clinical 
procedures 
 
Data analysis 
 
Problems anticipated 
 
All potential risks related to the study were addressed. If we cannot deliver a CAD/CAM crown as described in 
this study, we will deliver a PFM as an alternative solution. 
 
Project management 
 
1) Se-Lim Oh: obtaining CR from the IRB, recruiting participants, performing surgeries, data obtaining, data 
analysis with Dr. Yang 
2) Luz Abrera-Crum: recruiting participants, performing restorative procedures, data obtaining 
3) Seung Kee Choi: blind evaluator 
4) Ji Seung Yang; analyzing data 
 
Ethics 
 
The study protocol was approved by the IRB at the University of Maryland, Baltimore (HP-00073913). The 
protocol is currently CR5. The approval letter is attached (Appendix 2). 
 
The process of obtaining informed consent from the research participants is described as follows. 
1) Before meeting with potential participants 
The PI will verify that the consent form is approved by the IRB and is the most current version. 
 
2) At the meeting with potential participants 
A potential subject will be referred to the PI or research team members from dental providers at the UMSOD. 
The referral procedures are independent of the study. 
 
The PI or research team members will explain that the nature of the study, its purpose, procedures, expected 
duration and the benefits and risks of participation in accordance with Federal regulations in a separate private 
clinic room at the UMSOD. 
 
The potential participant will be informed of his/her rights to privacy. The potential participant is encouraged to 
ask questions. PI will ask the potential participant if questions have been answered to their satisfaction. The 
participant will be given the opportunity to review the consent alone or to review it with study personnel. The 
potential participants are encouraged to take the informed consent at home and discuss it with family and 
significant others. 
 
3) Filing out the consent form 
If the potential participant decides to enroll, he/she will sign and enter the date on the current approved 
consent form. The PI or a co-investigator who obtains the consent will sign and date the informed consent form. 
The PI will keep the original informed consent form with the participant’s study file in a locked cabinet at the 
room 4211. The participant will keep a hard copy of the original informed consent form. 
 
4) HIPAA 
During the informed consent process the participant will also sign the research HIPAA form. The PI or a co- 
investigator who conducts the informed consent process will explain to the participant that by signing the 
HIPAA form he/she authorizes his/her medical information to be shared with those parties listed on the form for 
the purposes of the research study. If the participant does not agree to sign the HIPAA form, he/she cannot 

12 
 
participate in the study. The original HIPAA form will be kept with the original consent form in the participant's 
study file. 
 
Potential participants will receive research information in a separate private room at the UMSOD clinics to secure priva 
Participants will be given ample time to read and assess the consent form. They will also be given as much 
time as needed to ask questions. The questions will be answered to their satisfaction. 
 
If a participant presents for each appointment, a participant is implicitly willing to be in the study. Therefore, we 
will not consider for ongoing consent. 
However, re-consenting may be required for various reasons including but not limited to cases where: 
1) The original consent form was not properly executed (missing date, time, checkboxes, etc) 
2) The study has been amended (i.e. changes in the study procedures affecting current participants) 
 
Informed consent forms 
The research informed consent form is attached (Appendix 3). 

Appendix 1 
 
Data and Safety Monitoring Report 
 
Protocol Title: The Use of Intraoral Imaging at Clinical Crown Lengthening Procedures 
Principal Investigator: Se-Lim Oh 
Co-monitoring person: Radi Masri 
 
IRB#: HP-00073913 
Date of the last IRB approval: 4/15/2020 
 
The previous CR for the approved IRB protocol was obtained in April 2020. As of March 
14, 2021, twenty-six subjects were enrolled and randomly assigned either to the 
experimental group or to the control group in this study. 
 
Seven subjects were excluded from the study. 
Five subjects were dropped out of the study. Three participants have withdrawn from the 
study without any specific reasons. No crowns have been delivered to these three 
subjects. Two participants received a porcelain-fused metal crown instead of a CAD/CAM 
crown because there was too much loss in tooth structure. Therefore, the two participants 
were excluded from the study. 
Two subjects received crown lengthening surgeries and CAD/CAM crowns, but they did 
not present for any follow-ups. 
 
The final e-max crowns were delivered for 19 subjects. No complications were observed 
in these subjects during the study period. No analysis was performed pending the 
completion of data collection. 
 
The included information above were shared with the monitor (Dr. Masri), and no 
concerns or additional actions were recommended. 
 
Se-Lim Oh 
Clinical Associate Professor 
University of Maryland School of Dentistry 
 
 
 
Radi Masri 
Professor 
University of Maryland School of Dentistry 

1 of 2 
 
Appendix 2 
 
 
 
 
 
 
APPROVAL OF RESEARCH NOTIFICATION 
University of Maryland, Baltimore 
Institutional Review Board (IRB) 
Phone: (410) 706-5037 
Fax: 
(410) 706-4189 
Email: hrpo@umaryland.edu 
 
OF NOTE: The Principal Investigator should review the University of Maryland Baltimore criteria for 
performing research during the current COVID-19 pandemic emergency. Understand that IRB approval of 
this research does not suggest that performance of this research under current guidelines is allowed. Failure 
to comply with the UMB President's directives would be considered non-compliance. The UMB Research 
directives can be found at https://www.umaryland.edu/coronavirus/ . If you need clarification or guidance 
please call the Human Research Protections Office at 410-706-5037. 
 
 
Date: February 11, 2022 
To: Se-Lim Oh 
RE: HCR-HP-00073913-5 
Type of Submission: Continuing Review 
Type of IRB Review: Expedited 
 
Approval for this project is valid from 2/11/2022 to 2/10/2023 
 
 
This is to certify that the University of Maryland, Baltimore (UMB) Institutional Review Board (IRB) approved the 
continuing review report for the above referenced protocol entitled, “The Use of Intraoral Imaging at Clinical 
Crown Lengthening Procedures”. 
 
The IRB has determined that this protocol qualifies for expedited review pursuant to Federal regulations 45 CFR 
46.110, 21 CFR 56.110, & 38 CRF 16.110 category(ies): 
(8)(c) - Continuing review of research previously approved by the convened IRB where the remaining research 
activities are limited to data analysis. (For a multi-center protocol, an expedited review procedure may be used by 
the IRB at a particular site whenever these conditions are satisfied for that site.) 
 
 
The IRB made the following determinations regarding this submission: 
- Written informed consent is required. Only the valid IRB-approved informed consent form(s) in CICERO can be 
used. 
- A waiver of HIPAA authorization for release of the PHI identified in the CICERO application has been reviewed 
and approved for recruitment purposes only. 
 
 
This study is approved to enroll 34 local participants. 
 
This study is approved to enroll 34 worldwide participants. 
 
Below is a list of the documents attached to your application that have been approved: 
informed consent_hp00073913_hshsl (2).docx 

2 of 2 
 
informed consent_hp00073913_hshsl (3).docx 
Eligibility Checklist for HP-00073913_2 v2-11-2018-1518365546057 
The research protocol_3.pdf 
HIPAA_CLP.docx 
 
 
In conducting this research you are required to follow the requirements listed in the INVESTIGATOR MANUAL. 
Investigators are reminded that the IRB must be notified of any changes in the study. In addition, the PI is 
responsible for ensuring prompt reporting to the IRB of proposed changes in a research activity, and for ensuring 
that such changes in approved research, during the period for which IRB approval has already been given, may not 
be initiated without IRB review and approval except when necessary to eliminate apparent immediate hazards to the 
subject (45 CFR 46.103(4)(iii)). The PI must also inform the IRB of any new and significant information that may 
impact a research participant’s safety or willingness to continue in the study and any unanticipated problems 
involving risks to participants or others. 
 
DHHS regulations at 45 CFR 46.109 (e) require that continuing review of research be conducted by the IRB at 
intervals appropriate to the degree of risk and not less than once per year. The regulations make no provision for 
any grace period extending the conduct of the research beyond 2/10/2023. You will receive continuing review 
email reminder notices prior to this date; however, it is your responsibility to submit your continuing review report 
in a timely manner to allow adequate time for substantive and meaningful IRB review and assure that this study is 
not conducted beyond 2/10/2023. Investigators should submit continuing review reports in the electronic system at 
least six weeks prior to this date. 
 
Research activity in which the VA Maryland Healthcare System (VAMHCS) is a recruitment site or in which VA 
resources (i.e., space, equipment, personnel, funding, data) are otherwise involved, must also be approved by the 
VAMHCS Research and Development Committee prior to initiation at the VAMHCS. Contact the VA Research 
Office at 410-605-7000 ext. 6568 for assistance. 
 
The UMB IRB is organized and operated according to guidelines of the International Council on Harmonization, the 
United States Office for Human Research Protections and the United States Code of Federal Regulations and 
operates under Federal Wide Assurance No. FWA00007145. 
 
If you have any questions about this review or questions, concerns, and/or suggestions regarding the Human 
Research Protection Program (HRPP), please do not hesitate to contact the Human Research Protections Office 
(HRPO) at (410) 706-5037 or HRPO@umaryland.edu. 

Appendix 3 
 
 
 
RESEARCH CONSENT FORM 
 
Protocol Title: The Use of Intraoral Imaging at Clinical Crown Lengthening Procedures 
Study No.: HP-00073913 
Principal Investigator: Se-Lim Oh, DMD, MS / 410-706-3708 
 
Sponsor: The American Dental Education Association and the department of Advanced Oral Sciences 
and Therapeutics 
 
You are invited to take part in a research study. Taking part in this study is voluntary. You do not have to take 
part. This consent form contains information about the study that will help you decide if you want to take part or 
not. Please read this form carefully. If you have questions, you may ask them any time. 
 
PURPOSE OF STUDY 
The purpose of this study is to test a new procedure that could shorten the time to fix a tooth with a crown for 
certain patients. The process of fixing a tooth with a crown can take longer if not enough of the tooth sticks out 
above the gum line. In such cases, the dentist needs to expose more of the tooth by removing some gum tissue or 
bone. The process of exposing the tooth in this way is called “crown lengthening surgery.” 
 
When a crown lengthening surgery is needed, the dentist typically performs this surgery first. The patient is then 
given about 3 months to heal before the dentist begins making a crown. This healing period often delays the 
delivery of a final crown. 
 
In this study, we will test a method where we make the final impression for the crown during the surgery. We will 
compare the results of this method with the standard method where the impression is made 3 months after 
surgery. If the new method is effective, it could help patients receive a permanent crown sooner. 
 
You qualify for this study because a crown lengthening surgery is required to make a crown. 
 
PROCEDURES 
If you are diabetic, your HbA1c must be below 6.5% in order to participate in this study. You are required to 
provide your HbA1c level verified by your primary care provider. The A1c level accepted needs to be within 3 
months. 
 
This study will last about 3 years. Your role in the study will last around 18 months. If you take part in this study, 
you will be placed in one of two treatment groups: 
1. 
Group 1 (the experimental group) will have crown lengthening surgery with a final impression made at the 
time of surgery 
2. 
Group 2 (the control group) will have crown lengthening surgery with a final impression made about 3 
months after surgery. This is considered as the standard protocol. 
 
The treatment you get will be chosen by chance, like flipping a coin. Neither you nor the study doctor will choose 
what treatment you get. You will have an equal chance of being given each treatment. If you are placed in the 
control group, you will have three more visits compared to those in the experimental group. However, these are 
not research procedures. There will be no additional costs because of the three more visits. The final 

impression will be made by intraoral imaging (intraoral camera) in both groups. 
 
We will take x-rays of your tooth when you get your crown(s), and at a follow-up visit after 12 months. These x- 
rays are standard care at UMB. You will not receive any additional radiation by participating in this study. 
Clinical photographs will be taken at baseline, surgery, delivery of crown(s), and each follow-up visit. These are 
also considered standard care at UMB. 
 
The following procedures will be performed in the experimental group. 
1) Appointment 1(30-40 minutes): A screening visit. Clinical examination and taking clinical photographs will 
be done. 
2) Appointment 2 (60-90 minutes): Cavity removal, filling and initial tooth preparation will be performed under 
local anesthesia. 
3) Appointment 3 (120 minutes): A clinical crown lengthening under local anesthesia will be performed. The 
final impression will be made with intraoral imaging (intraoral camera) at surgery. 
4) Appointment 4 (60 to 120 minutes): Suture removal and a final crown delivery 2 weeks after the surgery will 
be performed. X-rays will be taken to verify the fitting of a crown. 
5) Appointment 5 (30 minutes): Examination of bite and gum tissue 4 weeks after the delivery of a crown. 
6) Appointment 6 (40-60 minutes): 6 months after the crown delivery. Examination and cleaning will be 
performed. 
7) Appointment 7 (40-60 minutes): 12 months after the crown delivery. Examination, taking x-rays, and 
cleaning will be performed. 
 
The following procedures will be performed in the control group. 
1) Appointment 1(30-40 minutes): A screening visit. Clinical examination and taking clinical photographs will 
be done. 
2) Appointment 2 (60-90 minutes): Cavity removal, core build-up and initial tooth preparation will be performed 
under local anesthesia. 
3) Appointment 3 (90 minutes): A clinical crown lengthening under local anesthesia will be performed. 
4) Appointment 4 (30 minutes): Suture removal and postoperative follow-up 
5) Appointment 5 (30 minutes): Evaluation of gum tissue 4 weeks after the surgery 
6) Appointment 6 (60-120 minutes): The final impression will be made with intraoral imaging (intraoral 
camera) 12 weeks after the surgery. 
7) Appointment 7 (60-120 minutes): A final crown delivery. X-rays will be taken to verify the fitting of a 
crown. 
8) Appointment 8 (30 minutes): Examination of bite and gum tissue 4 weeks after the delivery of crown. 
9) Appointment 9 (40-60 minutes): 6 months after the crown delivery. Examination and cleaning will be 
performed. 
10) Appointment 10 (40- 60 minutes): 12 months after the crown delivery. Examination, taking x-rays, and 
cleaning will be performed. 
 
WHAT ARE MY RESPONSIBILITIES IF I TAKE PART IN THIS RESEARCH? 
If you take part in this research, you will be responsible to be present for each procedure and to follow the 
instructions of the research team. 
 
POTENTIAL RISKS/DISCOMFORTS: 
Taking part in this study will expose you to some potential risks from what you would have from routine crown 
lengthening surgery and crown placement. 
 
Risks from gum surgery and crown placement in both groups: 
• 
There might be bleeding after the surgery. Pressure dressing will be used to prevent bleeding. 
• 
There might be some pain after the surgery. Pain medicine will be prescribed. 
• 
Infection rarely occurs after the gum surgery. However, if infection develops, an antibiotic will be prescribed. 
• 
You may feel some discomfort after the procedures. This discomfort will subside within two weeks. 

• 
The crown may or may not need adjustments in both groups. 
• 
The gum receding may or may not occur after the crown delivery in both groups. 
 
Risks when you are placed in the experimental group. 
• 
There is a chance it might not be as successful as standard of care. 
Risk for loss of confidentiality in both groups: As with any study, there is a risk that your study data might not be 
kept confidential. We will be minimize this risk by storing data in a secure location, such as a locked office and 
locked cabinet. Electronic data will be password-protected. 
 
POTENTIAL BENEFITS 
You may or may not benefit by taking part in this study. There is no guarantee that you will receive direct benefit 
from your participation in this study. Knowledge gained from this study could help others in the future. If you are 
placed in the experimental group, you will get a crown earlier. 
 
ALTERNATIVES TO PARTICIPATION 
Standard of care/conventional treatment is available outside the study. You may also choose to receive temporary 
filling instead of a crown or receive no treatment. If you choose not to take part, your healthcare at UMB will not 
be affected. 
 
COSTS TO PARTICIPANTS 
1) You are responsible for the fees of a crown lengthening procedure ($451) and a final crown ($543). 
2) Root canal therapy (RCT) may be indicated. RCT is not the procedure related to this study. You are responsible 
for the fee ($300 to $800) for RCT. 
3) You are responsible for co-pays and deductible in cases that your dental insurance covers the above procedures 
4) You are responsible for parking fees. 
 
PAYMENT TO PARTICIPANTS 
The cost of cavity removal and filling ($100 to $150) will be waived. The fee for periodic oral exam ($37) and 
cleaning ($67) at 6-months and 12-months follow-ups will be waived. 
 
CONFIDENTIALITY AND ACCESS TO RECORDS 
To protect your privacy, study data will be stored in a file cabinet in a locked office. All electronic data will be 
password protected. Only research team members in this study and the Institutional Review Board (IRB) will 
have access to study data. 
The data from the study may be published. However, you will not be named. Certain people from the institutions 
where the study is being done will be able to view sections of your medical and research records related to the 
study. Everyone using study information will work to keep your personal information confidential. Your personal 
information will not be given out unless required by law. 
 
RIGHT TO WITHDRAW 
Your participation in this study is voluntary. You do not have to take part in this research. You are free to 
withdraw your consent at any time. If you refuse to take part, or if you stop taking part in the study, you will face 
no penalty or loss of benefits to which you are entitled. 
 
Please contact the investigator Dr. Se Lim Oh at 410-706-3708 if any of the following occur: 
• 
You decide to stop taking part in the research. 
• 
You have questions, concerns, or complaints about the research. 
• 
You need to report a medical injury related to the research. 
 
If you choose to withdraw from the research, there will be no adverse consequences. If you withdraw, you will 
continue to receive treatment as a regular patient. 
If you decide to withdraw from the research, a written withdrawal is required to Dr. Se-Lim Oh. 

If you withdraw from this study, already collected data may not be removed from the study database. You will be 
asked whether the investigator can collect data from your routine dental care. If you agree, this data will be 
handled the same as research data. 
You will be told if any significant findings develop during the study that could affect your choice to remain in the 
study. 
If you are an employee or student, your employment status or academic standing at UMB will not be affected by 
your choice to take part or not take part in this study. 
 
CAN I BE REMOVED FROM THE RESEARCH? 
The person in charge of the research study can remove you from the research study without your approval. 
Possible reasons for removal include failure to follow instructions from the research staff and if the person in 
charge decides that the research study is no longer in your best interest. The study doctor will tell you about this 
and you will have the chance to ask questions if this were to happen. 
 
DENTAL SCHOOL RESEARCH POLICY STATEMENT 
It is the Dental School’s policy that all research participants being seen at the Dental School must be registered in 
the School’s patient records system. It is also the Dental School’s policy that the care received by research 
participants can be reviewed by appropriate Dental School personnel under the Dental School’s quality assurance 
program. These policies help the Dental School to verify that your dental care is appropriate, and to provide 
continued care when research participation has concluded. If you consent to participate in research, please 
understand that you are agreeing that your personal information will be entered in the Dental School’s patient 
records, and that members of the quality assurance staff will have access to your dental information. The records 
concerning your dental care are confidential as required by law of Maryland and the U.S. 
 
UNIVERSITY STATEMENT CONCERNING RESEARCH RISKS 
The University of Maryland, Baltimore (UMB) is committed to providing participants in its research the rights 
due them under State and federal law. You give up none of your legal rights by signing this consent form or by 
participating in the research project. This research has been reviewed and approved by the Institutional Review 
Board (IRB). Please call the Institutional Review Board (IRB) if you have questions about your rights as a 
research subject. 
 
Participating in research may result in an injury, as explained above. If you suffer an injury directly related to  
your participation in this project, UMB and/or one of its affiliated institutions or health care groups will help you 
obtain medical treatment for the specific injury and provide referrals to other health care facilities, as appropriate. 
UMB and/or its affiliated institutions or health care groups will not provide you with financial compensation or 
reimbursement for the cost of care provided to treat a research-related injury or for other expenses arising from a 
research-related injury. The institution or group providing medical treatment will charge your insurance carrier, 
you, or any other party responsible for your treatment costs. If you incur uninsured medical costs, they are your 
responsibility. The study staff can give you more information about this if you have a study injury. 
 
By signing this Consent Form, you are not giving up any legal rights. If this research project is conducted in a 
negligent manner and you are injured as a direct result, you may be able to recover the costs of care and other 
damages from the individuals or organizations responsible for your injury. 
 
If you have questions, concerns, complaints, or believe you have been harmed through participation in this 
research study as a result of researcher negligence, you can contact members of the IRB or the Human Research 
Protections Office (HRPO) to ask questions, discuss problems or concerns, obtain information, or offer input 
about your rights as a research participant. The contact information for the IRB and the HRPO is: 
 
University of Maryland School of Medicine 
Human Research Protections Office 
620 W. Lexington Street, Second Floor 
Page 4 of 5 

Baltimore, MD 21201 
410-706-5037 
 
 
Signing this consent form indicates that you have read this consent form (or have had it read to you), that your 
questions have been answered to your satisfaction, and that you voluntarily agree to participate in this research 
study. You will receive a copy of this signed consent form. 
 
If you agree to participate in this study, please sign your name below. 
 
 
 
 
 
 
 
Participant’s Signature 
 
 
Date:  
 
Investigator or Designee Obtaining 
Consent Signature 
 
 
Date: