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Long-term observation of periodontal condition following placement of removable partial dentures with rigid retainers and major connector in patients with/without diabetes: A retrospective study

Research output: Contribution to journalArticlepeer-review

Chie Watanabe, Junichiro Wada, Tomiharu Nagayama, Hirofumi Uchida, Koji Mizutani, Richard M. Foxton, Yo Shibata, Noriyuki Wakabayashi

Original languageEnglish
Pages (from-to)117-123
Number of pages7
JournalJournal of Prosthodontic Research
Issue number1

Bibliographical note

Funding Information: All the authors of this study appreciate all the participants in this study. This study was funded by grants (No. 19K19085) offered by the Ministry of Education, Culture, Sports, Science, and Technology of Japan. Publisher Copyright: © 2021 Japan Prosthodontic Society. All rights reserved.

King's Authors


Purpose: This retrospective study evaluated the periodontal tissues of the abutment teeth of removable partial dentures (RPDs) with rigid retainers and major connectors in patients with and without type 2 diabetes mellitus (T2D). Methods: A total of 313 patients who had been treated with RPDs, including rigid retainers and major connectors, were divided into two groups: T2D and non-T2D. The periodontal parameters and radiographic bone heights of the abutment teeth were evaluated at baseline and at a 5-year examination during supportive periodontal therapy (SPT). For patients with accessible standardized radiographs, bone density was analyzed based on the gray level (GL) using digital subtraction radiography (n = 83). Results: Overall, 739 abutment teeth (86 in the T2D group) of 235 patients (25 in the T2D group) were analyzed, and 95.0% (94.2% in the T2D group, and 95.2% in the non-T2D group) were maintained. The mean probing pocket depth significantly increased in both groups (p < 0.001). There were significant changes in the radiographic bone height (p = 0.038) and GL on the side of the denture base area (p = 0.048) in the T2D group compared to those in the non-T2D group. Conclusion: Regardless of T2D, RPDs with rigid retainers and major connectors could prevent the progression of periodontal disease and successfully maintain most of the abutment teeth during 5-years of SPT. However, T2D may be significantly associated with loss of bone height reduction and density on the side of the denture base area.

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