Crestal bone changes around implants with implant-abutment connections at epicrestal level or above Systematic review and meta-analysis

Purpose: The aim of this systematic review and meta-analysis was to evaluate crestal bone changes around implants when placing the implant-abutment connection at the crestal bone level or above. Materials and Methods: Medline (Pubmed), EMBASE, and Cochrane Library up to January 2014 were electronically and hand searched for any publications that evaluated radiographic crestal bone changes around nonsubmerged, rough-surfaced implants placed in healed sites in humans and loaded for a minimum of 1 year. Results: The search yielded 1,122 publications; 1,106 could not be included. After 16 full-text articles were read and subjected to inclusion and exclusion criteria, four were included. The mean difference was -0.29 mm (95% CI, -0.58 mm to -0.01 mm). Heterogeneity between studies was observed (I2 = 95%). Significantly more crestal bone change was seen in the epicrestal implant-abutment (bone level) connection group when compared to implants with the prosthetic connection above the crestal bone level (tissue level) (P < .00001). Conclusion: Dental implants at bone level show significantly less crestal bone change after 1 year of loading than tissue-level implants.