Statement of problem

How the performance of dental implants is related to their occlusogingival placement, crestal or subcrestal, is unclear.

Purpose

The purpose of this systematic review and meta-analysis was to evaluate marginal bone loss, implant survival rate, and peri-implant soft tissue parameters between implants placed at the crestal and subcrestal bone level.

Material and methods

Two independent reviewers searched the PubMed/MEDLINE, Embase, and Cochrane Library databases for randomized clinical trials published up to September 2020. The meta-analysis was based on the Mantel-Haenszel and the inverse variance methods (α=.05).

Results

The search identified 928 references, and 10 studies met the eligibility criteria. A total of 393 participants received 709 implants, 351 at crestal bone levels and 358 at subcrestal bone levels. Meta-analysis indicated that crestal bone level implants showed similar marginal bone loss to that seen with subcrestal bone level implants (mm) (P=.79), independent of the subcrestal level (P=.05) and healing protocol (P=.24). The bone level implant placement did not affect the implant survival rate (P=.76), keratinized tissue (mm) (P=.91), probing depth (mm) (P=.70), or plaque index (%) (P=.92).

Conclusions

The evidence suggests that both approaches of implant placement are clinically acceptable in terms of peri-implant tissue parameters and implant-supported restoration survival.

中文翻译：

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牙冠和牙冠下种植体的临床比较：系统评价和荟萃分析

问题陈述

牙种植体的性能如何与其咬合牙龈位置（牙冠或牙冠下）相关，尚不清楚。

目的

本系统回顾和荟萃分析的目的是评估种植体在牙槽嵴和牙槽骨水平下的边缘骨丢失、种植体存活率和种植体周围软组织参数。

材料与方法

两位独立评审员在 PubMed/MEDLINE、Embase 和 Cochrane 图书馆数据库中搜索了截至 2020 年 9 月发表的随机临床试验。荟萃分析基于 Mantel-Haenszel 和逆方差方法 (α=.05)。

结果

搜索确定了 928 篇参考文献，10 项研究符合资格标准。共有 393 名参与者接受了 709 颗种植体，其中 351 颗在牙槽骨水平，358 颗在牙槽骨水平。Meta 分析表明，嵴骨水平种植体的边缘骨丢失与嵴下骨水平种植体相似（mm）（P = .79），与嵴下水平（P = .05）和愈合方案（P = . 24)。骨水平种植体植入不影响种植体存活率 ( P =.76)、角化组织 (mm) ( P =.91)、探测深度 (mm) ( P =.70) 或斑块指数 (%) ( P =.92)。

结论

证据表明，两种种植体植入方法在种植体周围组织参数和种植体支持的修复体存活率方面都是临床可接受的。