Occlusal change in posterior implant-supported single crowns and its association with peri-implant bone level: a 5-year prospective study

Objectives This study aims to analyze the 5-year occlusal change in posterior implant- supported single crowns and the association between the relative occlusal force ( ROF) and peri-implant bone level. Materials and methods Partially edentulous patients who had received implant-supported single crowns in the posterior region were included. Occlusal examinations with a computerized occlusion analysis system were conducted at 0.5, 3, 6, 12, 24, 36, 48, and 60 months after delivery of the implant-supported single crown. The ROFs of implant- supported single crowns, mesial adjacent teeth, and control natural teeth were recorded. Intraoral periapical radiographs were taken at each follow-up time to evaluate marginal bone level (MBL). Ordinary least square regression was used to analyze the association between ROF and MBL. Results Thirty- seven posterior implant-supported single crowns in 33 participants (23.9 to 70.0 years) were followed up for 0.5 to 60 months [(42.4 +/- 26.0) months]. The ROF of implant-supported single crowns increased from 2 weeks to 3 months (P < 0.01) and increased continuously between all two sequential time points from 6 to 36 months, with significant differences (P < 0.05). Then ROFs of implant-supported single crowns were significantly higher than those of control teeth at 48 and 60 months (P < 0.05). Regression analysis showed that ROF was significantly associated with MBL with a coefficient of 0.008 (P < 0.05). Conclusion The ROFs of posterior implant-supported single crown have significant change during 5 years' follow-up. The association between ROF and MBL has limited clinical significance.