The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

Patient-reported outcomes of implant-assisted removable partial denture withmagnetic attachments: A 3-year progress report
Chun Wei Chang1, Manabu Kanazawa2, Maiko Iwaki2, Daisuke Sato4, Anna Miyayasu3, Yuriko
Komagamine1, Yuriko Kusumoto4, Yuka Abe4, Kazuyoshi Baba4, Shunsuke Minakuchi1
1

Gerodontology and Oral Rehabilitation, Tokyo Medical and Dental University (TMDU)
Digital Dentistry, Tokyo Medical and Dental University (TMDU)
3
Advanced Biomaterials, Tokyo Medical and Dental University (TMDU)
4
Department of Prosthodontics, Showa University School of Dentistry
2I. Introduction
In traditional free-end edentulous partial dentures, sinking of the denture base or insufficient
retention of the denture often leads to pain and discomfort, making it difficult to achieve patientsatisfaction. In recent years, the effectiveness of implant-assisted removable partial dentures (IARPD)
which implants are placed at the free-end edentulous area to support and stabilize the denture, has beensuggested. By placing implants behind the free-end edentulous area, the free-end is transformed into
an intermediate edentulous, which can prevent denture sinking and improve stability.
Previous studies have utilized different implant systems and attachments, and various patterns ofedentulous. In those studies, patient satisfaction has been suggested to improve. However, there havebeen few studies utilizing magnets attachments.

II. Objective
Aim of this study is to evaluate patient-reported outcomes in IARPD using short implants andmagnetic attachments through a prospective intervention study.

III. Materials and Methods
1 Recruitment of participants
Patients were recruited from who visited Tokyo medical and dental university hospital or Showa
university hospital between 2016 and 2019. Several inclusion and exclusion criteria were applied(Table1.), and a total of 30 patients which mandibular Kennedy Class I or II and distal extension
defects of three or more teeth were included in the study.
Table1. Inclusion and exclusion criteria
Inclusion・Age from 45 to 85.
・Kennedy Class I or II and distal extension defects of three or more teeth.
・At least one remaining tooth with crown and mobility one or less.
・Sufficient bone volume for the insertion of short implants.
・No considering the condition in maxilla.
Exclusion・Uncontrolled systemic diseases.
・Infectious diseases (HIV, HBV, HCV) or mental disorders.
・Temporomandibular joint disorders.
・Xerostomia (dry mouth).
・Oral motor disorders.
・Dementia.

[Web Presentation] PS4-2-1

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

2 Clinical proceduresFirst, a proper removable partial denture for participants was fabricated by prosthodontist. After thesurgery, a 6-week unload period has been required before the attachment of healing cap. 10 weeks
after surgery, stage 1 assessment has been carried out. Subsequently, 14 weeks after surgery, stage 2
assessment has been conducted. (Figure 1.)

Figure 1. Clinical procedures
3 Outcomes
1) Assessment periods
The assessment periods were as follows: Before implant placement as Stage 0, after healing cap
attached as Stage 1, after magnetic attachment attached as Stage 2. Following with the assessment at1-year, 2-year and 3-year after implant placement surgery. (Figure 2.)

Figure 2. Assessment periods2) Assessment methods
Based on patient-reported outcomes (PRO), patient satisfaction been assessed using a 100mm visualanalogue scale and oral health related quality of life (OHRQoL) using Oral Health Impact ProfileJapanese version (OHIP-J) score. Additionally, the OHIP was divided into four subdomains
established by JOHN et al. in 2014, and analyses were conducted for each of these subdomains. (Figure3.)[Web Presentation] PS4-2-2

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

Figure 3. Assessment methods3) Statistical analysis
To compare the PRO before implant placement (Stage 0) with each assessment period’s outcome
after implant placement, Steel's test was used. The statistical analysis was conducted using JMP Pro
17, with a significance level at 0.05.

IV. Results
Compared to Stage 0, patient satisfaction showed a significant improvement since IARPD withmagnetic attachments at Stage 2, as well as at 1 year, 2 years, and 3 years after implant placement.
(Figure 4.)
Summary score of OHIP-J54 showed a significant improvement at 2 years and 3 years after implant
placement. (Figure 5.)
Following up with each of the four subdomains of OHIP:
a. Oral function and orofacial appearance showed a significant difference at 2 years and 3 years
after implant placement. (Figure 6. 7.)
b. Orofacial pain exhibited a significant at 2 years after implant placement. (Figure 8.)c. However, there was no significant difference observed in psychosocial impact. (Figure 9.)

Figure 4. Patient satisfaction[Web Presentation] PS4-2-3

The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

Figure 5. Summary score of OHIP-J54

Figure 6. Oral Function

Figure 7. Orofacial Appearance

Figure 8. Orofacial Pain

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The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/

Figure 9. Psychosocial Impact

V. Discussions
1) Improvement of Patient Satisfaction
Studies by Gates et al. in 2014 and Jensen et al. in 2016, suggested that IARPD resulted in higher
patient satisfaction compared to traditional removable partial dentures, when the support force
increased.
However, the results in this study showed no significant improvement in patient satisfaction while
IARPD using a healing cap. In other hand, after magnetic attachments been attached, there was asignificant increase in patient satisfaction.
This suggests that the improvement of patient satisfaction is not only attributed to support force but
also to the increased retention force provided by magnetic attachments.
2) Improvement of OHRQoL
Summary score of OHIP-J54 and three subdomains: Oral function, Orofacial appearance, andOrofacial pain. IARPD showed a significant decrease compared to traditional removable partialdentures.
The use of magnetic attachments in IARPD suggested the potential for long-term maintenance of(OHRQoL).

VI. Conclusions
Despite the limitations of this study, the use of short implants and magnetic attachments in IARPD:
1) There were significant improvements in patient satisfaction, from immediately after magnetic
attachments was attached to 3 years after implant placement.
2) Oral health-related quality of life (OHRQoL) showed significant improvements at 2 and 3 years
after implant placement.

References
1) John MT, Feuerstahler L, Waller N, et al. Confirmatory factor analysis of the Oral Health Impact
Profile. J Oral Rehabil. 2014;41(9):644-652.
2) Gates WD 3rd, Cooper LF, Sanders AE, Reside GJ, De Kok IJ. The effect of implant-supported
removable partial dentures on oral health quality of life. Clin Oral Implants Res. 2014;25(2):207213.
3) Jensen C, Meijer HJA, Raghoebar GM, Kerdijk W, Cune MS. Implant-supported removablepartial dentures in the mandible: A 3-16 year retrospective study. J Prosthodont Res.
2017;61(2):98-105.

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The 23rd International Conference on Magnetic Applications in Dentistry (Feb. 26 to Mar 15, 2024)
http://jsmad.jp/international/23/4) Negoro M, Kanazawa M, Sato D, et al. Patient-reported outcomes of implant-assisted removablepartial dentures with magnetic attachments using short implants: A prospective study. JProsthodont Res. 2021;65(4):554-558.

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