Kütan Esma, Bolukbasi Nilufer, Yildirim-Ondur Esra, Ozdemir Tayfun
Department of Oral Implantology, Faculty of Dentistry, Yeditepe University, Istanbul Turkey.
Department of Oral Implantology, Faculty of Dentistry, Istanbul University, Istanbul, Turkey.
Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e364-75. doi: 10.1111/cid.12248. Epub 2014 Jul 17.
It has been reported in many articles that marginal bone resorptions are prevented by platform-switching design. However, what occurs when these implants are placed in the apical position is not completely known.
This report describes a randomized controlled clinical trial study that aims to test the hypothesis that less resorption will occur when platform-switching implants are placed 1 mm below bone level.
A total of 56 randomly selected implants were inserted bilaterally, either 1 mm below bone level (test group, 28 implants) or at bone level (control group, 28 implants) of the patients' posterior regions. Marginal bone resorptions were examined through periapical radiographies taken with the parallel technique at the time of crown cementation and the third, sixth, 12th, and 36th months after prosthetic loading. The modified plaque index, gingival index, bleeding on probing, and probing depths were used for follow-up periodontal care of the implants.
After 3 years, the mean radiographic vertical bone loss in the control group was significantly lower than in the test group (0.56 ± 0.35 mm and 1.21 ± 1.05 mm, respectively) (p < .01). In terms of periodontal indexes, there were no statistically significant differences between the two groups (p > .05). No peri-implantitis or peri-implant mucositis was observed around the test or control implants.
More marginal bone resorptions occurred after the third year of loading in implants placed 1 mm below bone level. However, the resorptions did not reach the implants thread. In the control group, the first bone implant contact was placed under the level of the first threads. Therefore, the present randomized clinical trial confirmed the hypothesis that placing platform-switching implants 1 mm below bone level reduced marginal bone loss. It can be noted that to reduce resorption, platform-switching implants should be placed below bone level.
许多文章报道平台转换设计可预防边缘骨吸收。然而，当这些种植体置于根尖位置时会发生什么尚不完全清楚。
本报告描述了一项随机对照临床试验研究，旨在检验以下假设：当平台转换种植体置于骨水平以下1毫米时，骨吸收会更少。
总共随机选择56颗种植体双侧植入患者后牙区，分别为骨水平以下1毫米（试验组，28颗种植体）或骨水平（对照组，28颗种植体）。在冠修复粘结时以及修复体加载后第3、6、12和36个月，采用平行投照技术拍摄根尖片检查边缘骨吸收情况。使用改良菌斑指数、牙龈指数、探诊出血和探诊深度对种植体进行随访牙周护理。
3年后，对照组的平均影像学垂直骨吸收明显低于试验组（分别为0.56±0.35毫米和1.21±1.05毫米）（p<0.01）。在牙周指数方面，两组之间无统计学显著差异（p>0.05）。试验组或对照组种植体周围均未观察到种植体周炎或种植体周围黏膜炎。
在骨水平以下1毫米植入的种植体在加载3年后发生了更多的边缘骨吸收。然而，骨吸收未到达种植体螺纹。在对照组中，首次骨与种植体接触位于第一螺纹水平以下。因此，本随机临床试验证实了以下假设：将平台转换种植体置于骨水平以下1毫米可减少边缘骨丢失。可以注意到，为减少骨吸收，平台转换种植体应置于骨水平以下。
