Influence of the abutment height on marginal bone level changes around two-piece dental implants: meta-analysis and trial sequential analysis of randomized clinical trials.

It might be cautiously concluded that two-piece implants with long abutments (≥2 mm) may display a protective role against marginal bone loss when compared to short ones (<2 mm) at < 1 year and ≥ 1 year. A more subcrestal implant position seemed to minimize the effect of the abutment height in terms of MBL.