- 期刊
A retrospective study of crestal bone changes at fixture-abutment junctions for implants with horizontal offsets
摘要
Purpose: The esthetics and longevity of dental implant-supported prostheses depend on the successful integration of peri-implant soft and hard tissues , with the phenomenon of early bone resorption up to 1.5 mm being a key factor for success. The purpose of this study was to track the effect of horizontal platform switching (PS) that hides microgaps in the height of the alveolar bone around the implant . Materials and methods: Periapical radiographs of 54 implants in the control group and 41 implants in the PS group were collected. These radiographs were digitized to measure the amount of peri-implant crestal bone resorption. Such data was recorded every 3 months between the baseline (2^(nd) stage surgery) and 12-month follow-up and every 12 months after the 1^(st) year of loading. The amounts of bone loss in both groups were compared using the Student t-test. Results: There was no significant difference in crestal bone loss between the control group and the PS group except at the 36-month follow-up (P＜0.03). The mean crestal bone loss was 1.20±0.67 mm in the control group and 1.18±0.59 mm in the PS group at 12 months. The annual bone loss after the 1^(st) year in the control group and the PS group was 0.12±0.3 mm and 0.08±0.35 mm, respectively. Conclusion: The amount of early peri-implant bone resorption and annual bone loss after the first year of loading in this study was comparable with the amounts reported in the literature. The results indicating no significant difference in crestal bone loss between the two groups may have been due to when the PS was performed. The smaller diameter abutments were connected to implant fixtures when the prostheses were delivered, rather than at the time of the surgical exposure of the implants. As for the effect of horizontal offsets on late implant bone loss, studies with larger sample sizes should be conducted. The results of this study indicated no significant difference in the amounts of crestal bone loss between the control group and the PS group except at the 36-month follow-up. These results suggest that a further study with a larger sample size and PS performed before the 2^(nd) stage surgery should be conducted to clarify the effect of PS.