Validity of a regenerative procedure for a minor bone defect with immediate implant placement: a systematic review and meta-analysis

<b>Objective:</b> This systematic review evaluates implant survival and the change in the width of the horizontal ridge following immediate implant placement with or without a regenerative procedure. <b>Materials and methods:</b> An electronic search of MEDLINE, EMBASE, and the LILACS database of the Cochrane Central Register of controlled trials was performed, along with a manual search, up to April 2018. Randomized controlled trials (RCTs) and quasi-randomized controlled clinical trials (CCTs) with &gt;10 subjects were eligible for this systematic review. A meta-analysis of the risk difference in implant failure between the regenerative and non-regenerative procedure groups was performed using a fixed-effect model. In addition, a meta-analysis of the change in alveolar bone width was conducted using a fixed-effect model. <b>Results:</b> Seven studies (six RCTs and one CCT) were included. A meta-analysis of three studies found no statistically significant risk difference in implant failure between the regenerative procedure and non-regenerative procedure groups. A meta-analysis of four studies showed that horizontal shrinkage of the alveolar ridge in the site of immediate implant placement was statistically significantly lower with the regenerative procedure than without it (&lt;1 year follow up studies: weighted mean difference (WMD) 0.75 mm, 95% confidence interval 0.41–1.09, <i>p</i> p = .00006; total: WMD 0.84 mm, 95% confidence interval 0.53–1.14, <i>p</i> <b>Conclusion:</b> Within the study limitations, immediate implant placement with a regenerative procedure showed similar implant survival and less shrinkage of the ridge width than immediate implant placement without a regenerative procedure. Due to the high risk of bias and small sample sizes of the included studies, further clinical studies are warranted to draw definitive conclusions.