title: Retrospective evaluation of crestal bone changes around implants with reduced abutment diameter placed non-submerged and at subcrestal positions: the effect of bone grafting at implant placement.
abstract: BACKGROUND
  There is limited information regarding the effect of grafting of the osteotomy after subcrestal implant placement. The primary aim of this study is to retrospectively evaluate the effect of bone grafting of the defect between the bone crest and the coronal aspect of implants with reduced abutment diameter placed non-submerged and at subcrestal positions.
  
  
  METHODS
  Records of 50 consecutive patients treated with subcrestally placed dental implants grafted with a xenograft (Group A) and 50 consecutive patients with subcrestally placed dental implants without any grafting material (Group B) were reviewed. For each implant, the radiographs after placement were compared to images from the last follow-up visit and evaluated regarding the following: 1) degree of subcrestal positioning of the implant, 2) changes of marginal hard-tissue height over time, and 3) whether marginal hard-tissue could be detected on the implant platform at the follow-up visit.
  
  
  RESULTS
  The mean marginal loss of hard tissues was 0.11 ± 0.30 mm for Group A and 0.08 ± 0.22 mm for Group B. Sixty-nine percent of the implants in Group A and 77% of the implants in Group B demonstrated hard tissue on the implant platform. There were no statistically significant differences between the groups regarding marginal peri-implant hard-tissue loss.
  
  
  CONCLUSIONS
  The present study fails to demonstrate that grafting of the remaining osseous wound defect between the bone crest and the coronal aspect of the implant has a positive effect on marginal peri-implant hard-tissue changes.
authors: Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL 32608, USA. tkoutouzis@dental.ufl.edu
authors: Theofilos
authors: T
authors: Koutouzis
authors: Michael
authors: M
authors: Fetner
authors: Alan
authors: A
authors: Fetner
authors: Tord
authors: T
authors: Lundgren
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology* / Q000517:prevention & control / Q000628:therapy; D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D001861:Bone Regeneration / Q000502:physiology; D016025:Bone Transplantation; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants / Q000009:adverse effects*; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation / Q000601:surgery; D008297:Male; D008875:Middle Aged; D013516:Oral Surgical Procedures, Preprosthetic / Q000379:methods; D016348:Osseointegration / Q000502:physiology*; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015921:Dental Implants