Influence of Laser-Microtextured Surface Collar on Marginal Bone Loss and Peri-Implant Soft Tissue Response: A Systematic Review and Meta-Analysis

Background: A laser-microtextured surface (LMS) dental implant collar appears to promote a more tooth-like gingival collagen fiber attachment, which may help to stabilize peri-implant tissues. The purpose of this systematic review is to assess the clinical effect of an LMS versus non-LMS collar on crestal bone level and peri-implant soft tissue response. Methods: Electronic and manual literature searches were performed by two independent reviewers for articles written in English up to December 2016. Studies were included if they were human clinical trials with the purpose of evaluating the impact of an LMS collar on peri-implant hard and soft tissues. Cumulative marginal bone loss (MBL), probing depth (PD), and survival rate (SR) with 95% confidence intervals (CIs) were calculated to show the performance of LMS implant collars. MBL, PD, and SR data were analyzed with a random effects model to compare the influence of LMS collars with non-LMS collars (e.g., roughened surface and machined surface). Results: Fifteen human clinical studies (three randomized controlled trials, six cohort studies, and six case series) with 772 implants met the inclusion criteria. For the overall data, the weighted mean MBL was 0.72 mm (95% CI: 0.59 to 0.85 mm), PD was 1.81 mm (95% CI: 1.13 to 2.49 mm), and SR was 0.97 (95% CI: 0.95 to 0.98). MBL around an LMS collar was significantly less than around machinedsurface collars (weighted mean difference [WMD]: -0.77; 95% CI: -1.01 to -0.52; I-2 = 95.2%; P < 0.001). PD in the LMS group was significantly shallower than in the machined-surface group (WMD: -1.34; 95% CI: -1.62 to -1.05; I-2 = 81.4%; P < 0.001). However, no statistically significant difference was detected for MBL between the LMS and roughened-surface groups (WMD: -0.04; 95% CI: -0.16 to 0.08; I-2 = 0.0%; P = 0.75). No statistically significant difference was found for SR between the LMS and non-LMS groups (risk ratio: 1.01; 95% CI: 0.97 to 1.04; I-2 = 0.0%; P = 0.91). Conclusions: Meta-analysis showed that an LMS collar can reduce the amount of MBL and PD compared with a machined-surface collar. Due to high heterogeneity between the included studies, results should be interpreted cautiously.