title: Comparative study of two collagen membranes for guided tissue regeneration therapy in periodontal intrabony defects: a randomized clinical trial.
abstract: OBJECTIVE
  THE PURPOSE OF THIS STUDY WAS TO ASSESS AND COMPARE THE CLINICAL AND RADIOGRAPHIC OUTCOMES OF GUIDED TISSUE REGENERATION THERAPY FOR HUMAN PERIODONTAL INTRABONY DEFECTS USING TWO DIFFERENT COLLAGEN MEMBRANES: a porous nonchemical cross-linking collagen membrane (NC) and a bilayer collagen membrane (BC).
  
  
  METHODS
  Thirty subjects were randomly assigned and divided into the following 3 groups: a test group (NC+BM), in which a NC was used with xenograft bone mineral (BM), a positive control group (BC+BM), in which a BC was used with xenograft BM, and a negative control group (BM), in which only xenograft BM was used. The following clinical measurements were taken at baseline and 3 months after surgery: plaque index, gingival index, probing pocket depth, gingival recession, and clinical attachment level. Radiographic analysis was performed at baseline, 1 week and 3 months after surgery.
  
  
  RESULTS
  Membrane exposure was not observed in any cases. Significant probing depth reduction, attachment-level gain and bone fill were observed for both test and control groups compared to baseline at 3 months after surgery (P<0.05). However, there were no statistically significant differences in clinical improvement and radiographic bone fill between treatment protocols (P>0.05).
  
  
  CONCLUSIONS
  Within the limitations of this study, the results suggest that both NC and BC were comparable in terms of clinical and radiographic outcomes for the treatment of periodontal intrabony defects in human subjects.
authors.affiliation: Department of Periodontology, Wonkwang University Daejeon Dental Hospital, Wonkwang University School of Dentistry, Daejeon, Korea.
authors.forename: Young-Mi
authors.identifier: 0000-0001-8365-8825
authors.initials: YM
authors.lastname: Chung
authors.affiliation: Research Institute, NIBEC, Seoul, Korea.
authors.forename: Jue-Yeon
authors.identifier: 0000-0002-4914-1862
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Wonkwang University Daejeon Dental Hospital, Wonkwang University School of Dentistry, Daejeon, Korea.
authors.forename: Seong-Nyum
authors.identifier: 0000-0003-4890-989X
authors.initials: SN
authors.lastname: Jeong
keywords: Chronic periodontitis; Collagen; Guided tissue regeneration