Meta-analysis of single crowns supported by short (<10 mm) implants in the posterior region.

ABSTRACT

AIM: To assess the failures and complications of short (<10 mm) implants supporting single crowns in the posterior region and its potential risk factors (RkF). MATERIALS AND METHODS: Prospective studies were screened according to eligibility criteria, followed by contact with authors. Quality assessment was performed using a standardized protocol. Mean implant failure proportion (FP), biological and prosthetic failure proportions (BFP/PFP) and marginal bone loss (MBL) including 95% confidence intervals were estimated using random-effects models for meta-analysis. RESULTS: Sixteen studies with a medium methodological quality (mean score 8 ± 3; 2-14) had data collected. In summary, 762 short implants were followed up for up to 120 months in 360 patients (mean follow-up 44 ± 33.72 months; mean dropout rate 5.1%). The means FP, BFP, PFP and MBL were 5.9% (95%CI 3.7-9.2%), 3.8% (95%CI 1.9-7.4%), 2.8% (95%CI 1.4-5.7%) and 0.83 mm (95%CI 0.54-1.12 mm) respectively. Quantitative analysis showed that placement in the mandible (p = 0.0002) and implants with length ≤8 mm (p = 0.01) increased FP, BFP and MBL, whereas qualitative assessment revealed that crown-to-implant ratio did not influence MBL. CONCLUSIONS: Single crowns supported by short implants in the posterior region are a predictable treatment option with reduced failure rates, biological/prosthetic complications and minimal bone loss.