title: Reasons for marginal bone loss around oral implants.
abstract: BACKGROUND
  The reasons for long-term marginal bone loss around oral implants are not well understood.
  
  
  OBJECTIVE
  The aim of this paper is to analyze presented evidence behind anticipated reasons for long-term marginal bone loss around oral implants.
  
  
  METHODS
  A computerized research was conducted on PubMed in April 2011 with the following keywords: oral implants and marginal bone resorption/crestal bone loss/bone loss/bone resorption. This search resulted in a total of one thousand one hundred ninety-four papers of which seven hundred fifty-three were clinical contributions. Further search and filtering finally resulted in 21 experimental studies and one hundred sixteen clinical studies, which were reviewed.
  
  
  RESULTS
  No evidence was found that primary infection caused marginal bone resorption. Clinical papers that have reported high levels of peri-implantitis were not supported by data given. Clinical evidence was presented that the so-called combined factors (implant hardware, clinical handling, and patient characteristics) may lead to marginal bone resorption. However, once tissue damage has been caused by combined factors, inflammation and/or infection may develop secondarily and then result in peri-implantitis that may need particular clinical treatment.
  
  
  CONCLUSIONS
  As marginal bone loss primarily depends on numerous background factors, it seems logical that, for example, the use of poorly constructed implants placed and handled by untrained clinicians may result in high numbers of patients with secondary problems in form of peri-implantitis; having said this, control of combined factors may likewise lead to very good clinical results where peri-implantitis would represent a very rare disease indeed even at follow-up times of 10 years or more.
authors.affiliation: Department of Prosthodontics, College of Stomatology, Kunming Medical University, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Qian
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
authors.forename: Tomas
authors.initials: T
authors.lastname: Albrektsson
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology*; D000818:Animals; D001862:Bone Resorption; D003758:Dental Implantation, Endosseous / Q000009:adverse effects*; D015921:Dental Implants / Q000009:adverse effects*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D057873:Peri-Implantitis / Q000209:etiology; D012307:Risk Factors
chemical_list: D015921:Dental Implants