A systematic review on marginal bone loss around short dental implants (<10 mm) for implant-supported fixed prostheses.

PURPOSE This systematic review aimed to evaluate the effect of implant length on peri-implant marginal bone loss (MBL) and its associated influencing factors. MATERIAL AND METHODS An electronic search of the PubMed and MEDLINE databases for relevant studies published in English from November 2006 to July 2012 was performed by one examiner (AM). Selected studies were randomized clinical trials, human experimental clinical trials or prospective studies (e.g., cohort as well as case series) with a clear aim of investigating marginal bone loss of short dental implants (<10 mm) supporting fixed prostheses. A random-effect meta-regression model was used to determine the relationship between the effect size mean MBL and the covariate "implant length." Additionally, a subgroup analysis, by means of a random-effect one-way ANOVA model, comparing mean MBL values at different levels of each factor ("type of connection" and "type of prostheses") was also performed. RESULTS The meta-regression of mean MBL on the moderator "implant length" was found to be insignificant (P = 0.633). Therefore, it could not be concluded that implant length had an effect on peri-implant MBL. In addition, standardized differences in mean MBL on the subgroups short (<10 mm) and standard (≥ 10 mm) implants, as determined by the meta-analysis (random-effect model), were found to be statistically insignificant (P = 0.222). CONCLUSIONS Within limitations of the present systematic review, it could be concluded that short dental implants (<10 mm) had similar peri-implant MBL as standard implants (≥ 10 mm) for implant-supported fixed prostheses.