title: Long-term results of guided tissue regeneration therapy in the treatment of class II furcation defects: a randomized clinical trial.
abstract: BACKGROUND
  The purpose of this study was to evaluate the results after guided tissue regeneration (GTR) using a bioabsorbable membrane in Class II furcation defects in mandibular molars over a 24-month period.
  
  
  METHODS
  Nine patients with 2 comparable Class II furcation defects were included. The defects in each patient were randomly assigned to either test (GTR) or control (open flap debridement) group. Clinical measurements and standardized radiographs were taken at baseline, and at 6, 12, 18, and 24 months. The radiographs were analyzed by subtraction radiography.
  
  
  RESULTS
  There were significant probing depth reductions for both test and control groups (P < 0.007, P < 0.0005, respectively); however the differences between groups were not significant at any examination. The intra-group and inter-group differences in the vertical clinical attachment level gain were not significant (P > 0.05). Over 24 months, a significant horizontal clinical attachment level gain was observed in the test group compared to control (P<0.03). In the test group, 2 sites showed complete closure, one was converted to Class I, and one tooth was lost due to root resorption. In the control group, 2 defects progressed to Class III over 24 months. At 6 months, the test group showed 0.14 mm of bone loss while the control group showed 0.86 mm of bone gain (P = 0.035). The inter-group differences were not significant at 12, 18, and 24 months. A significant bone height gain was observed in the test group at 24 months when compared to the values obtained after 6 months (P = 0.015).
  
  
  CONCLUSIONS
  GTR may provide a greater horizontal clinical attachment level gain with the possibility of complete closure of some defects and stability over time.
authors.affiliation: Department of Prosthodontics and Periodontics, Division of Periodontics, School of Dentistry at Piracicaba, University of Campinas, Piracicaba, Brazil.
authors.forename: P R
authors.initials: PR
authors.lastname: Cury
authors.forename: E A
authors.initials: EA
authors.lastname: Sallum
authors.forename: F H
authors.initials: FH
authors.lastname: Nociti
authors.forename: A W
authors.initials: AW
authors.lastname: Sallum
authors.forename: M K
authors.initials: MK
authors.lastname: Jeffcoatt
mesh_terms: D020341:Absorbable Implants; D000539:Alveolar Process / Q000000981:diagnostic imaging; D003646:Debridement; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D017823:Furcation Defects / Q000145:classification / Q000000981:diagnostic imaging / Q000601:surgery*; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery; D008567:Membranes, Artificial; D008875:Middle Aged; D008963:Molar; D017622:Periodontal Attachment Loss / Q000145:classification / Q000601:surgery; D010514:Periodontal Pocket / Q000145:classification / Q000601:surgery; D011859:Radiography; D012391:Root Resorption / Q000209:etiology; D013223:Statistics as Topic; D013382:Subtraction Technique; D013524:Surgical Flaps; D016388:Tooth Loss / Q000209:etiology; D014945:Wound Healing
chemical_list: D008567:Membranes, Artificial