title: Survival analysis of wide dental implant: systematic review and meta-analysis.
abstract: OBJECTIVE
  Wide-diameter implants are frequently placed in molar sites to obtain appropriate restoration profiles, to rescue implants that lack stability, and to engage bone in extraction sites. However, studies of wide-diameter implant placement have provided conflicting evidence regarding clinical outcomes. This systematic review aims to analyze survival rates of wide-diameter implants (platform diameter ≥5 mm) and assess clinical variables potentially affecting failure rates.
  
  
  METHODS
  Electronic search was conducted using MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE from January 1980 to October 2014. Publication screening, data extraction, and quality assessment were performed. Failure rate per implant-year was analyzed using mix-effects Poisson regression model to obtain summary estimates of the 5-year survival rate. Relative risk (RR) was calculated to evaluate the association of different clinical variables with estimated failure rates.
  
  
  RESULTS
  Eleven retrospective studies and eight prospective studies having at least 1-year follow-up period were included in the analysis. The estimated 5-year survival rate was 92.67% (95% confidence interval: [79.60, 97.50]) in the retrospective studies and 97.76% (Confidence interval: [93.25, 99.27]) in the prospective studies. Implant surface and implant diameter were significantly associated with the failure events in the retrospective studies.
  
  
  CONCLUSIONS
  Placement of wide-diameter implants demonstrated a promising survival rate during 5-year follow-up. Further controlled trials with the control group and longer follow-up period are needed to provide the direct evidence comparing survival rates of wide implants with survival rates of narrower implants.
authors.affiliation: Department of Periodontics and Dental Hygiene, University of Texas Health Science Center at Houston, Houston, TX, USA.
authors.forename: Chun-Teh
authors.identifier: http://orcid.org/0000-0001-7812-5637
authors.initials: CT
authors.lastname: Lee
authors.affiliation: Oral and Maxillofacial Surgery, Department of Stomatology, Taipei Veterans General Hospital and School of Dentistry, National Yang-Ming University, Taipei, Taiwan.|Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital and Harvard School of Dental Medicine, Boston, MA, USA.
authors.forename: Ya-Wei
authors.initials: YW
authors.lastname: Chen
authors.affiliation: Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, MA, USA.
authors.forename: Jacqueline R
authors.initials: JR
authors.lastname: Starr
authors.affiliation: Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital and Harvard School of Dental Medicine, Boston, MA, USA. sungkiangchuang@gmail.com.
authors.forename: Sung-Kiang
authors.initials: SK
authors.lastname: Chuang
mesh_terms: D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D016019:Survival Analysis
chemical_list: D015921:Dental Implants
keywords: dental implants; evidence-based dentistry; meta-analysis; survival analysis; treatment outcome