Marginal bone loss one year after implantation: a systematic review of different loading protocols

The aim of this study was to analyse the influence of different loading protocols on marginal bone loss (MBL). The outcomes of different implant loading protocols were assessed at 1year after implantation, with focus on MBL; protocols included immediate, immediate non-occlusal, early, and conventional loading. The search strategy resulted in 889 studies. Twenty-two of these studies fulfilled the inclusion criteria. Among the included studies, the lowest MBL was for immediately loaded implants (0.05+/-0.67mm) and the highest for immediate non-occlusally loaded implants (1.37+/-0.5mm). The results of the meta-analysis showed an estimated mean MBL of 0.457mm (95% confidence interval (CI) 0.133-0.781) for immediate loading, 0.390mm (95% CI 0.240-0.540) for immediate non-occlusal loading, 0.488mm (95% CI 0.289-0.687) for early loading (>2 days to <3 months), and 0.852mm (95% CI 0.429-1.275) for conventional loading (>3 months) implant protocols. The lowest decrease in 1-year implant survival per millimetre increase in MBL was observed for immediate loading and the highest for conventional loading. Conventional loading showed a significantly higher MBL than the other three loading protocols. This systematic review and meta-analysis indicates that the immediate loading protocol is a reasonable alternative to the conventional loading protocol.