title: Impact of implant surface and grafting protocol on clinical outcomes of endosseous implants.
abstract: OBJECTIVE
  The objectives of this study were to (1) evaluate the survival of implants placed in maxillary sinuses augmented with a 70:30 mixture of autogenous bone and anorganic bovine hydroxyapatite (Bio-Oss) at 1 and 5 years, (2) observe the difference in survival rate between 1-stage and 2-stage procedures, and (3) compare the survival rate of rough-surfaced implants with that of machined implants.
  
  
  METHODS
  A total of 30 consecutively patients (48 sinuses) with Cawood and Howell Class V and VI atrophy were evaluated. Lateral osteotomy techniques were used in all cases. Implants were placed either simultaneous with grafting (1-stage procedure) or after a delay (2-stage procedure), depending on the amount of residual bone. A 70:30 mixture of autogenous bone and anorganic bovine hydroxyapatite was used as the graft material. All patients were followed up at 1 year after prosthetic loading, while a limited group of these patients was followed up to 5 years.
  
  
  RESULTS
  In 8 patients where the residual crestal bone under the sinus floor assessed by computed tomography was at least 4.5 mm (mean, 5.3 mm), the 1-stage procedure was used for 11 sinus elevations and 32 implants. In 22 patients where the residual crestal bone was less than 4.5 mm (mean, 2.5 mm), the 2-stage procedure was used for 37 sinus elevations and 108 implants. For the 140 implants placed, the overall survival rate was 95.7% at the healing abutment surgery, and the cumulative survival rate was 94.9% at 1 and 5 years. The type of surgical technique was significantly associated with implant failure (P < .05); implants placed using the 1-stage procedure showed a failure rate of 12.5%, while implants placed with the 2-stage procedure had a failure rate of 2.8%. No significant difference in survival rate was observed with respect to implant surface.
  
  
  CONCLUSIONS
  A high survival rate was achieved when sinus elevation was performed with a combination of autogenous bone and anorganic bovine hydroxyapatite, even where a minimal amount of residual crestal bone was present. The survival rate was improved when implants were placed after a healing period.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Bologna, Italy. claudio.marchetti@bo.nettuno.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Marchetti
authors.forename: Francesco
authors.initials: F
authors.lastname: Pieri
authors.forename: Stefano
authors.initials: S
authors.lastname: Trasarti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Corinaldesi
authors.forename: Marco
authors.initials: M
authors.lastname: Degidi
mesh_terms: D000328:Adult; D000368:Aged; D000540:Alveolar Ridge Augmentation / Q000379:methods; D000818:Animals; D002417:Cattle; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D019232:Dental Restoration Failure; D005260:Female; D006085:Graft Survival; D006801:Humans; D008297:Male; D008443:Maxillary Sinus / Q000601:surgery; D008875:Middle Aged; D018709:Statistics, Nonparametric; D013499:Surface Properties
chemical_list: D015921:Dental Implants