title: Guided bone regeneration with and without a bone substitute at single post-extractive implants: 1-year post-loading results from a pragmatic multicentre randomised controlled trial.
abstract: OBJECTIVE
  To evaluate whether the adjunctive use of a bone substitute at immediate single implants placed in fresh extraction sockets with a residual buccal bone-to-implant gap of at least 1 mm could improve the aesthetic outcome of guided bone regeneration (GBR).
  
  
  METHODS
  Eighty patients requiring bone augmentation at a single immediate postextractive implant to improve the aesthetic outcome were randomly allocated to an augmentation procedure using a resorbable barrier alone (GBR group; 40 patients) or a bone substitute plus a resorbable barrier (GBR + BS group; 40 patients) according to a parallel group design at four different centres. Three to 4 months after implant placement/augmentation, implants were loaded with provisional or definitive single crowns. Outcome measures were implant failures, complications, aesthetics assessed using the pink esthetic score (PES), patient satisfaction and peri-implant marginal bone levels, recorded by blinded assessors. All patients were followed up to 1 year after loading.
  
  
  RESULTS
  One patient dropped out from the GBR group. Seven (9%) implants failed: 2 (5%) in the GBR + BS group and 5 (12.5%) in the GBR group. Six minor complications occurred in the GBR + BS group versus 2 in the GBR group. These differences were not statistically significant. Just after implant placement/augmentation, mean bone levels were -0.21 mm at GBR + BS implants and -1.92 mm at GBR implants whereas at 1 year after loading they were -1.04 and -1.76, respectively. When comparing the two groups, GBR + BS implants had 0.70 mm more peri-implant marginal bone than GBR implants. Aesthetics was scored by a blinded assessor as statistically significantly better for the GBR + BS group. Patients were equally satisfied. There were no differences between centres regarding the clinical outcomes.
  
  
  CONCLUSIONS
  The use of additional an organic bovine bone substitute (Endobon) with resorbable collagen barriers (OsseoGuard) in defects around post-extractive implant improves the aesthetic outcome, though single post-extractive implants might be at a higher risk for implant failures.
authors.affiliation: Department of Periodontology, University of Genoa, Genoa, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: De Angelis
authors.forename: Pietro
authors.initials: P
authors.lastname: Felice
authors.forename: Gerardo
authors.initials: G
authors.lastname: Pellegrino
authors.forename: Andrea
authors.initials: A
authors.lastname: Camurati
authors.forename: Paolo
authors.initials: P
authors.lastname: Gambino
authors.forename: Marco
authors.initials: M
authors.lastname: Esposito
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000000981:diagnostic imaging; D000540:Alveolar Ridge Augmentation / Q000379:methods; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000627:therapeutic use*; D003094:Collagen; D003442:Crowns; D019250:Dental Implants, Single-Tooth; D019232:Dental Restoration Failure; D004955:Esthetics, Dental; D005260:Female; D005500:Follow-Up Studies; D048091:Guided Tissue Regeneration / Q000379:methods*; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D016348:Osseointegration / Q000502:physiology; D017060:Patient Satisfaction; D011183:Postoperative Complications; D011859:Radiography; D013280:Stomatitis / Q000209:etiology; D020390:Tooth Socket / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018786:Bone Substitutes; D008567:Membranes, Artificial; C104266:endobon; D003094:Collagen