title: Clinical and histologic assessment of lateral alveolar ridge augmentation using a synthetic long-term bioabsorbable membrane and an allograft.
abstract: BACKGROUND
  Guided bone regeneration (GBR) is a widely used procedure for augmenting alveolar ridge width prior to placement of endosseous implants. Various graft materials and barrier membranes (non-resorbable and bioabsorbable) have been used in GBR. The aim of this study was to assess the performance of a new bioabsorbable, synthetic polyglycolic acid/trimethylene carbonate (PGA/TMC) barrier membrane with an increased absorption time in conjunction with a combination of assayed demineralized bone matrix and cortical cancellous chips uniformly dispersed in a thermoplastic biologic carrier.
  
  
  METHODS
  At 72 potential implant sites in 38 subjects, ridge width at the crest and 4 mm apical to the crest was measured before and 6 months after a GBR procedure using the long-term (LT) PGA/TMC membrane and an allograft in a thermoplastic carrier. Before placement of endosseous implants, 48 biopsy specimens were obtained from the augmentation sites and analyzed histomorphometrically.
  
  
  RESULTS
  The GBR procedure increased the mean ridge width at the crest from 2.4 to 5.2 mm. This 216% change from baseline was significant (P <0.001). The mean width 4 mm apical to the crest increased from 4.4 to 7.5 mm, a significant (P <0.001) 174% change. The histomorphometric analysis showed that the biopsy specimens consisted, on average, of 57% bone (36% graft material and 21% new bone) and 43% soft tissue and space.
  
  
  CONCLUSIONS
  Our findings suggest that the LT PGA/TMC barrier membrane, used in conjunction with an allograft, provides lateral alveolar ridge augmentation comparable to that achieved with other materials without the necessity for bone-graft harvesting or a second procedure to remove the barrier membrane.
authors.affiliation: Department of Periodontology, University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35294-0007, USA. ngeurs@uab.edu
authors.forename: Nicolaas C
authors.initials: NC
authors.lastname: Geurs
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Korostoff
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Vassilopoulos
authors.forename: Tae-Heon
authors.initials: TH
authors.lastname: Kang
authors.forename: Marjorie
authors.initials: M
authors.lastname: Jeffcoat
authors.forename: Robert
authors.initials: R
authors.lastname: Kellar
authors.forename: Michael S
authors.initials: MS
authors.lastname: Reddy
mesh_terms: D020341:Absorbable Implants; D000042:Absorption; D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000473:pathology*; D000540:Alveolar Ridge Augmentation / Q000295:instrumentation / Q000379:methods*; D001706:Biopsy; D001857:Bone Matrix / Q000637:transplantation; D016025:Bone Transplantation / Q000473:pathology; D015921:Dental Implants; D004146:Dioxanes / Q000737:chemistry; D005260:Female; D005500:Follow-Up Studies; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D010012:Osteogenesis / Q000502:physiology; D011100:Polyglycolic Acid / Q000737:chemistry; D013529:Surgical Wound Dehiscence / Q000209:etiology; D013530:Surgical Wound Infection / Q000209:etiology; D014184:Transplantation, Homologous
chemical_list: D015921:Dental Implants; D004146:Dioxanes; D008567:Membranes, Artificial; D011100:Polyglycolic Acid; C443643:trimethylene carbonate