title: A systematic review of guided tissue regeneration for periodontal infrabony defects.
abstract: OBJECTIVE
  To systematically review the evidence for efficacy of guided tissue regeneration (GTR) for infrabony defects.
  
  
  BACKGROUND
  The evidence for the efficacy of GTR has not yet been systematically appraised.
  
  
  METHODS
  We searched for randomised controlled trials of at least 12 months' follow-up comparing GTR with open flap debridement (OFD). Data sources included electronic databases, hand-searched journals and contact with experts. Screening, data abstraction and quality assessment were conducted independently by multiple reviewers. The primary outcome measure was gain in clinical attachment.
  
  
  RESULTS
  For attachment level change, the weighted mean difference between GTR alone and open flap debridement was 1.11 mm (95% CI: 0.63-1.59), chi-square for heterogeneity 31.4 (9 df ), P < 0.001) and for GTR + bone substitutes was 1.25 mm (95% CI: 0.89-1.61, chi-square for heterogeneity 0.01 (1 df), P = 0.91). The number of sites needed to treat (NNT) for GTR to achieve one extra site gaining 2 mm or more attachment over open flap debridement was 8 (95% CI: 4-33). Heterogeneity between studies was highly statistically significant for all principal comparisons and could not be explained satisfactorily by sensitivity analyses.
  
  
  CONCLUSIONS
  Overall, GTR was more effective than OFD in improving attachment levels. However, there was marked variability between studies and general conclusions about the clinical benefit of GTR are limited by this heterogeneity. Future studies should aim to identify factors associated with achieving consistent benefits over open flap debridement. Open flap surgery should remain the control comparison in these studies.
mesh_terms: D016301:Alveolar Bone Loss / Q000601:surgery; D015982:Bias; D018786:Bone Substitutes / Q000627:therapeutic use; D016009:Chi-Square Distribution; D016001:Confidence Intervals; D003646:Debridement; D005500:Follow-Up Studies; D005889:Gingival Recession / Q000601:surgery; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D017622:Periodontal Attachment Loss / Q000601:surgery; D010510:Periodontal Diseases / Q000601:surgery*; D010514:Periodontal Pocket / Q000601:surgery; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013524:Surgical Flaps; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes