title: The Effect of Vertical Implant Position in Relation to Adjacent Teeth on Marginal Bone Loss in Posterior Arches: A Retrospective Study.
abstract: OBJECTIVE
  The aim of this retrospective study was to investigate the possible association between peri-implant marginal bone loss and the apicocoronal (vertical) positioning of dental implants placed adjacent to a tooth.
  
  
  METHODS
  Dental records at the University of Michigan, School of Dentistry, were screened. To be included in the study, the patient had to have at least one implant in the premolar or molar region, unilaterally or bilaterally, in either arch, with an immediately mesial adjacent tooth. The implant had to have been functionally loaded for at least 3 years after crown insertion, and clear, nondistorted periapical films had to be available. Several landmarks were identified: the cementoenamel junction (CEJ) and crestal bone (CB) of the tooth adjacent to the implant, the implant platform (PL), and the first radiographic implant-bone contact (BL). The following parameters were measured: CEJ-PL, CEJ-CB, CB-PL, horizontal distance between the adjacent tooth and PL (HD), and vertical distance between BL and the first implant thread at the mesial (BL-m) and distal (BL-d) implant surfaces.
  
  
  RESULTS
  A total of 139 patients with a mean age of 62.1 ± 9.3 years were included. The mean follow-up period was 4.42 ± 2.5 years. When the implant was placed more than 3 mm apical to the CEJ of the adjacent tooth, significantly greater peri-implant bone loss occurred at the mesial (difference of means = 0.57 mm) and distal (difference of means = 0.83 mm) implant surfaces.
  
  
  CONCLUSIONS
  In this study population, implants placed in the posterior area with a vertical distance greater than 3 mm from the CEJ of the adjacent tooth displayed more peri-implant bone loss. Further investigation is required to determine whether this increased peri-implant bone loss predisposes a site to peri-implantitis.
authors.forename: James
authors.initials: J
authors.lastname: Mailoa
authors.forename: Jia-Hui
authors.initials: JH
authors.lastname: Fu
authors.forename: Hsun-Liang
authors.initials: HL
authors.lastname: Chan
authors.forename: Vahid
authors.initials: V
authors.lastname: Khoshkam
authors.forename: Jeff
authors.initials: J
authors.lastname: Li
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D016301:Alveolar Bone Loss / Q000145:classification* / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000000981:diagnostic imaging; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D000069343:Bone-Implant Interface / Q000000981:diagnostic imaging; D003442:Crowns; D003724:Dental Arch / Q000000981:diagnostic imaging / Q000601:surgery*; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D008875:Middle Aged; D016300:Radiography, Bitewing; D012189:Retrospective Studies; D014070:Tooth / Q000000981:diagnostic imaging*; D019237:Tooth Cervix / Q000000981:diagnostic imaging
chemical_list: D015921:Dental Implants