CosmORAL Oral and Dental Health Polyclinics, Section of Prosthodontics, Ankara, Turkey.
Clin Oral Implants Res. 2010 Dec;21(12):1327-33. doi: 10.1111/j.1600-0501.2010.01952.x.
The aim of this retrospective study was to compare the frequency of spontaneous early exposure of cover screws and marginal bone resorption in conventionally and early-placed submerged implants before second-stage surgery.
A total of 103 Nobel Biocare Branemark implants were conventionally (Group 1), or early-placed (Group 2) in 46 consecutive patients following the two-stage surgical protocol. Patients in both groups received oral hygiene training in self-performed plaque control measures, including exposure of cover screws during healing. Spontaneous cover screw exposure (CSE) of each implant was recorded for both groups and scored from Class 0 (no perforation) to Class 4 (complete exposure). Plaque index scores were recorded and marginal bone-level (MBL) changes were measured in radiographs before second-stage surgery in a blind manner.
MBL in Group 2 was higher than Group 1 in patients with or without interim prosthesis (P<0.05). The use of interim prosthesis did not increase MBL in Group 1, but led to higher MBL in Group 2. The percentage of non-exposed implants in Group 1 was higher than Group 2 (P=0.007, odds ratio=7). Group 1 implants had 11.5 times greater plaque index score 0 than those in Group 2 (P=0.031, odds ratio=11.5). The differences between MBL with regard to CSE scores 0 and 1-4 was significant for both sides in Group 2 and the mesial side in Group 1 (P<0.05). The difference between MBL with regard to plaque index scores 1-3 was similar in both groups (P>0.05).
There is a direct relation between spontaneous early cover screw perforations with early crestal bone loss. Early-placed implants experienced more spontaneous perforations and associated bone loss in comparison with conventionally placed submerged implants. The use of interim dentures may lead to more CSE and consequent MBL in the early-placement protocol.
本回顾性研究旨在比较二期手术前常规和早期埋入式种植体的覆盖螺丝自发性早期暴露和边缘骨吸收的频率。
46 例连续患者按两期手术方案，采用常规方法（1 组）或早期埋入（2 组）植入 103 枚诺贝尔 Biocare Branemark 种植体。两组患者均接受口腔卫生培训，自行进行菌斑控制措施，包括愈合期暴露覆盖螺丝。记录两组每个种植体的自发性覆盖螺丝暴露（CSE）情况，并按 0 级（无穿孔）至 4 级（完全暴露）进行评分。盲法记录二期手术前菌斑指数评分，并测量边缘骨水平（MBL）变化。
有或无临时修复体的患者中，2 组 MBL 均高于 1 组（P<0.05）。使用临时修复体并未增加 1 组的 MBL，但导致 2 组 MBL 升高。1 组非暴露种植体的比例高于 2 组（P=0.007，优势比=7）。1 组种植体的菌斑指数评分 0 显著高于 2 组（P=0.031，优势比=11.5）。2 组双侧和 1 组近中侧 CSE 评分 0 与 1-4 之间的 MBL 差异有统计学意义（P<0.05）。两组菌斑指数评分 1-3 之间的 MBL 差异无统计学意义（P>0.05）。
自发性早期覆盖螺丝穿孔与早期牙槽骨丧失之间存在直接关系。与常规埋入式种植体相比，早期埋入式种植体更容易出现自发性穿孔和相关骨丢失。使用临时义齿可能会导致早期植入方案中更多的 CSE 和随之而来的 MBL。
