title: Early implant placement with simultaneous guided bone regeneration following single-tooth extraction in the esthetic zone: a cross-sectional, retrospective study in 45 subjects with a 2- to 4-year follow-up.
abstract: BACKGROUND
  The concept of early implant placement is a treatment option in postextraction sites of single teeth in the anterior maxilla. Implant placement is performed after a soft tissue healing period of 4 to 8 weeks. Implant placement in a correct three-dimensional position is combined with a simultaneous guided bone regeneration procedure to rebuild esthetic facial hard and soft tissue contours.
  
  
  METHODS
  In this retrospective, cross-sectional study, 45 patients with an implant-borne single crown in function for 2 to 4 years were recalled for examination. Clinical and radiologic parameters, routinely used in implant studies, were assessed.
  
  
  RESULTS
  All 45 implants were clinically successful according to strict success criteria. The implants demonstrated ankylotic stability without signs of a peri-implant infection. The peri-implant soft tissues were clinically healthy as indicated by low mean plaque (0.42) and sulcus bleeding index (0.51) values. None of the implants revealed a mucosal recession on the facial aspect as confirmed by a clearly submucosal position of all implant shoulders. The mean distance from the mucosal margin to the implant shoulder was -1.93 mm on the facial aspect. The periapical radiographs showed stable peri-implant bone levels, with a mean distance between the implant shoulder and the first bone-implant contact of 2.18 mm.
  
  
  CONCLUSIONS
  This retrospective study demonstrated successful treatment outcomes for all 45 implants examined. The mid-term follow-up of 2 to 4 years also showed that the risk for mucosal recession was low with this treatment concept. Prospective clinical studies are required to confirm these encouraging results.
authors.affiliation: Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, Bern, Switzerland. daniel.buser@zmk.unibe.ch
authors.forename: Daniel
authors.initials: D
authors.lastname: Buser
authors.forename: Michael M
authors.initials: MM
authors.lastname: Bornstein
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Weber
authors.forename: Linda
authors.initials: L
authors.lastname: Grütter
authors.forename: Bruno
authors.initials: B
authors.lastname: Schmid
authors.forename: Urs C
authors.initials: UC
authors.lastname: Belser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000539:Alveolar Process / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D003442:Crowns; D003758:Dental Implantation, Endosseous / Q000379:methods*; D019250:Dental Implants, Single-Tooth; D003774:Dental Plaque Index; D019094:Dental Prosthesis, Implant-Supported; D004955:Esthetics, Dental; D005260:Female; D005500:Follow-Up Studies; D005889:Gingival Recession / Q000145:classification; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D010486:Periapical Tissue / Q000000981:diagnostic imaging; D017622:Periodontal Attachment Loss / Q000145:classification; D010514:Periodontal Pocket / Q000145:classification; D011859:Radiography; D012189:Retrospective Studies; D014081:Tooth Extraction; D016896:Treatment Outcome