title: [Influence of the placing depth of implants with platform switching on the marginal bone level in the posterior mandible: a clinical study].
abstract: OBJECTIVE
  The purpose of this study was to evaluate the influence of the placing depth of the implants with platform switching (Ankylos) on the marginal bone remodeling, by means of radiological observation.
  
  
  METHODS
  111 Ankylos implants in the posterior mandible from 46 patients (20 male and 27 female) were enrolled in this study. Followed up by 58.1 months on average (from 36 to 85), 222 mesial and distal sites of these implants were evaluated by means of measuring the level of the marginal bone (LMB) on the panoramic radiograph.
  
  
  RESULTS
  Among these 111 successfully functional loaded implants, there were no significant differences with the marginal bone absorption values, no matter the implants were placed below, at, or above the bone level (P>0.05). Concerning the stabilization of the marginal bone, when placed below the bone level, 67.7% of the implant sites had their LMBs stabilized at or above the implant platform, and 23.3% absorbed vertically, respectively 19.7% and 80.3% when placed at the bone level, with significant difference (P<0.001).
  
  
  CONCLUSIONS
  Based on a long-term (over 3 years) observation, the implants placed below, as compared to at or above, the alveolar crest level, might have more chance to keep the marginal bone stabilized at or above the implant platform.
authors.affiliation: Department of Oral Implantology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Luo
authors.forename: Xiu-lian
authors.initials: XL
authors.lastname: Hu
authors.forename: Ye
authors.initials: Y
authors.lastname: Lin
authors.forename: Li-xin
authors.initials: LX
authors.lastname: Qiu
authors.forename: Ping
authors.initials: P
authors.lastname: Di
authors.forename: Jian-hui
authors.initials: JH
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss; D016723:Bone Remodeling; D001862:Bone Resorption; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult