title: Risk Factors in Early Implant Failure: A Meta-Analysis.
abstract: BACKGROUND
  Clinicians should be able to weigh the role of the main risk factors associated with early implant failure.
  
  
  OBJECTIVE
  The aim of this meta-analysis was to assess the influence of different patient-related and implant-related risk factors on the occurrence of early implant failure.
  
  
  METHODS
  In July, 2014 the main electronic databases were searched for studies reporting on early failures. Relevant papers were selected by 2 independent authors using predefined selection criteria. Three authors independently scored the included studies for quality assessment. The estimated odds ratios of the main risk factors from the selected papers were subjected to meta-analysis.
  
  
  RESULTS
  Nine studies were included. A total of 18,171 implants were meta-analyzed, of which 10,921 were analyzed for smoking, 15,260 for implant diameter, 16,075 for implant length, and 16,711 for implant location (maxilla vs mandible). The main significant risk factors for early implant failures were the smoking habit (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.3, 2.3), implants shorter than 10 mm (OR, 1.6; 95% CI, 1.2, 2.2) and implants placed in the maxilla (OR, 1.3; 95% CI, 1.0, 1.6).
  
  
  CONCLUSIONS
  Clinicians should be aware of the increased risk of early failure in the presence of smokers, implants with reduced length, and implant-supported maxillary rehabilitation.
authors.affiliation: *Postgraduate Student, Master in Dental Sciences, University of Salamanca (USAL), Salamanca, Spain. †Tenured Lecturer in Prosthodontics, Department of Surgery, Faculty of Medicine, University of Salamanca (USAL), Salamanca, Spain. ‡Tenured Lecturer in Statistics, Department of Statistics, School of Nursing, University of Salamanca (USAL), Salamanca, Spain. §Associate Professor, Head of Section of Oral Physiology, Department of Biomedical, Surgical and Dental Sciences, IRCCS Galeazzi Institute, University of Milan, Milan, Italy. ¶Professor of Preventive and Community Dentistry, Faculty of Odontology, University of Granada, Granada, Spain. ‖Visiting Professor, Head of the Section of Implant Dentistry and Oral Rehabilitation, Department of Biomedical, Surgical, and Dental Sciences, Dental Clinic (Chairman: Prof. R.L. Weinstein), IRCCS Galeazzi Institute, University of Milan, Milan, Italy.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Manzano
authors.forename: Javier
authors.initials: J
authors.lastname: Montero
authors.forename: Javier
authors.initials: J
authors.lastname: Martín-Vallejo
authors.forename: Massimo
authors.initials: M
authors.lastname: Del Fabbro
authors.forename: Manuel
authors.initials: M
authors.lastname: Bravo
authors.forename: Tiziano
authors.initials: T
authors.lastname: Testori
mesh_terms: D003757:Dental Implantation / Q000009:adverse effects; D015921:Dental Implants / Q000009:adverse effects*; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D006801:Humans; D012307:Risk Factors; D013997:Time Factors
chemical_list: D015921:Dental Implants