title: Comparison of implant and provisional placement protocols in sinus-augmented bone: a preliminary report.
abstract: OBJECTIVE
  To evaluate preliminary data on clinical outcomes associated with timing of placement of single implant-supported provisional crowns and implants in augmented bone.
  
  
  METHODS
  Twenty patients underwent sinus elevation bone grafting followed by a 6-month healing period before implant placement and immediate placement of a provisional crown (group [G] 1); 20 patients received sinus elevation bone grafting at the time of implant placement and immediate placement of a provisional crown (G2); 20 patients required no bone augmentation before implant placement and immediate placement of a provisional crown (G3); and 20 patients received sinus elevation bone grafting followed by a 6-month healing period before implant placement followed by a 6-month healing period before restoration (G4). The height of the crestal bone was measured and recorded to determine mean bone changes, and success rates were determined.
  
  
  RESULTS
  Mean bone level comparisons were made between G2 and G3, G2 and G4, and G3 and G4. No statistically significant differences were found between the groups (P < .05). G1 was discontinued based on the initial results: two implants did not meet the 35-Ncm insertion test, and one implant failed within 1 month after implant placement. The 1-year implant survival rates were 86% (n = 12/14), 95% (n = 19/20), and 100% (n = 16/16) for G2, G3, and G4, respectively. Differences in survival rates between the groups were not statistically significant (P < .05).
  
  
  CONCLUSIONS
  Implant survival is affected by the timing of sinus augmentation and implant placement in relation to the timing of crown placement. Implants that were restored immediately regardless of the timing of bone augmentation showed greater failure rates than implants in augmented bone with delayed restoration protocols or those that were restored immediately in sites without bone augmentation. Neither the timing of loading nor timing of implant placement in relation to bone augmentation surgery affected mean bone loss.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Lang
authors.forename: Wendell A
authors.initials: WA
authors.lastname: Edgin
authors.forename: Lily T
authors.initials: LT
authors.lastname: Garcia
authors.forename: Norma
authors.initials: N
authors.lastname: Olvera
authors.forename: Ronald
authors.initials: R
authors.lastname: Verrett
authors.forename: David
authors.initials: D
authors.lastname: Bohnenkamp
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Haney
mesh_terms: D016301:Alveolar Bone Loss / Q000601:surgery*; D016025:Bone Transplantation / Q000379:methods*; D003442:Crowns; D003758:Dental Implantation, Endosseous / Q000379:methods*; D019250:Dental Implants, Single-Tooth; D019094:Dental Prosthesis, Implant-Supported / Q000379:methods*; D019232:Dental Restoration Failure; D005500:Follow-Up Studies; D006801:Humans; D011184:Postoperative Period; D011446:Prospective Studies; D059546:Sinus Floor Augmentation / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome