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

AimTo assess the failures and complications of short (<10mm) implants supporting single crowns in the posterior region and its potential risk factors (RkF). Materials and MethodsProspective 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. ResultsSixteen studies with a medium methodological quality (mean score: 83; 2-14) had data collected. In summary, 762 short implants were followed up for up to 120months in 360 patients (mean follow-up: 44 +/- 33.72months; 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 0.83mm (95%CI: 0.54-1.12mm) respectively. Quantitative analysis showed that placement in the mandible (p=0.0002) and implants with length 8mm (p=0.01) increased FP, BFP and MBL, whereas qualitative assessment revealed that crown-to-implant ratio did not influence MBL. ConclusionsSingle 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.