title: A randomized clinical trial to evaluate and compare implants placed in augmented versus non-augmented extraction sockets: 3-year results.
abstract: BACKGROUND
  The alveolar ridge undergoes reabsorption and atrophy subsequent to tooth removal and thus exhibits a wide range of dimensional changes. Preservation of the alveolar crest after tooth extraction is essential to enhance the surgical site before implant fixture placement. The aim of this randomized clinical study is to investigate and compare the need for additional augmentation procedures at implant insertion, as well as the success rate and marginal bone loss for implants placed in the grafted sites versus those placed in naturally healed sites.
  
  
  METHODS
  Forty patients with ≥1 hopeless tooth were randomly allocated to: 1) a test group, receiving extraction and grafting corticocancellous porcine bone; and 2) a control group, receiving extraction without any graft. After 7 months of healing, implants were inserted in each of the sites. The implants were submerged and loaded after 4 months with metal-ceramic rehabilitation. The follow-up included evaluation of implant diameter and length, the need for additional augmentation procedures at implant placement, implant failure, and marginal bone level changes. All patients were followed over a 3-year period.
  
  
  RESULTS
  One implant failed in the control group at the second stage of surgery (6 months after placement); one implant failed in the test group after 2 years of loading. The cumulative implant success rate at the 3-year follow-up visit reached 95% for both groups. No statistically significant differences were detected for marginal bone changes between the two groups.
  
  
  CONCLUSIONS
  It was concluded that implants placed into grafted extraction sockets exhibited a clinical performance similar to implants placed into non-grafted sites in terms of implant survival and marginal bone loss. However, grafted sites allowed placement of larger implants and required less augmentation procedures at implant placement when compared to naturally healed sites.
authors.affiliation: Department of Surgery, University of Pisa, Pisa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Barone
authors.forename: Bruno
authors.initials: B
authors.lastname: Orlando
authors.forename: Luciano
authors.initials: L
authors.lastname: Cingano
authors.forename: Simone
authors.initials: S
authors.lastname: Marconcini
authors.forename: Giacomo
authors.initials: G
authors.lastname: Derchi
authors.forename: Ugo
authors.initials: U
authors.lastname: Covani
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000601:surgery; D000539:Alveolar Process / Q000473:pathology; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D016723:Bone Remodeling / Q000502:physiology; D018786:Bone Substitutes / Q000627:therapeutic use; D016025:Bone Transplantation / Q000379:methods; D003442:Crowns; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D011446:Prospective Studies; D013524:Surgical Flaps; D014081:Tooth Extraction; D020390:Tooth Socket / Q000601:surgery*; D014183:Transplantation, Heterologous; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; D015921:Dental Implants; D008567:Membranes, Artificial