title: A systematic review of the incidence of biological and technical complications in implant dentistry reported in prospective longitudinal studies of at least 5 years.
abstract: OBJECTIVE
  To systematically review the incidence of biological and technical complications in implant therapy reported in prospective longitudinal studies of at least 5 years.
  
  
  METHODS
  A MEDLINE search was conducted for prospective longitudinal studies with follow-up periods of at least 5 years. Screening and data abstraction were performed independently by multiple reviewers. The types of complications assessed were as follows: implant loss, sensory disturbance, soft tissue complications, peri-implantitis, bone loss >or=2.5 mm, implant fracture and technical complications related to implant components and suprastructures.
  
  
  RESULTS
  The search provided 1310 titles and abstracts, out of which 159 were selected for full-text analysis. Finally, 51 studies were included. Meta analysis of these studies indicated that implant loss prior to functional loading is to be expected to occur in about 2.5% of all implants placed in implant therapy including more than one implant and when routine procedures are used. Implant loss during function occurs in about 2-3% of implants supporting fixed reconstructions, while in overdenture therapy >5% of the implants can be expected to be lost during a 5-year period. Few studies (41% of those included) reported data on the incidence of persisting sensory disturbance >1 year following implant surgery. Most of the studies that provided such data reported on the absence or a low incidence (1-2%) of this complication beyond this interval. A higher incidence of soft tissue complications was reported for patients treated with implants supporting overdentures. There is limited information regarding the occurrence of peri-implantitis and implants exhibiting bone loss >or=2.5 mm. Implant fracture is a rare complication and occurs in <1% of all implants during a 5-year period. The incidence of technical complications related to implant components and suprastructures was higher in overdentures than in fixed reconstructions.
  
  
  CONCLUSIONS
  Implant loss was most frequently described (reported in about 100% of studies), while biological complications were considered in only 40-60% and technical complications in only 60-80% of the studies. This observation indicates that data on the incidence of biological and technical complications may be underestimated and should be interpreted with caution.
authors.affiliation: Department of Periodontology, Faculty of Odontology, The Sahlgrenska Academy at Göteborg University, Sweden.
authors.forename: Tord
authors.initials: T
authors.lastname: Berglundh
authors.forename: Leif
authors.initials: L
authors.lastname: Persson
authors.forename: Björn
authors.initials: B
authors.lastname: Klinge
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology; D003758:Dental Implantation, Endosseous / Q000009:adverse effects*; D015921:Dental Implants / Q000009:adverse effects*; D019094:Dental Prosthesis, Implant-Supported / Q000009:adverse effects; D019232:Dental Restoration Failure; D003828:Denture, Overlay / Q000009:adverse effects; D006801:Humans; D010518:Periodontitis / Q000209:etiology; D011446:Prospective Studies; D020886:Somatosensory Disorders / Q000209:etiology
chemical_list: D015921:Dental Implants