title: Meta-analysis of single crowns supported by short (<10 mm) implants in the posterior region.
abstract: OBJECTIVE
  To assess the failures and complications of short (<10 mm) implants supporting single crowns in the posterior region and its potential risk factors (RkF).
  
  
  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.
authors.affiliation: Department of Prosthodontics, Post-Graduate Program in Dentistry, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Luis André
authors.initials: LA
authors.lastname: Mezzomo
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Miller
authors.forename: Diego
authors.initials: D
authors.lastname: Triches
authors.forename: Fernando
authors.initials: F
authors.lastname: Alonso
authors.forename: Rosemary Sadami A
authors.initials: RS
authors.lastname: Shinkai
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology; D003442:Crowns; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D012307:Risk Factors
keywords: meta-analysis; partially edentulous patients; posterior region; short implants; single crown; systematic review