Aims:The present study was undertaken to evaluate the effectiveness of the combination of hydroxyapatite and β-tricalcium phosphate bone alloplast with bioresorbable guided tissue regeneration membrane for the treatment of mandibular grade II furcation defects.Settings and Design:A total of eight patients, four females and four males, in the age group of 18 to 65 years, with bilateral buccal grade II furcation defects in the mandibular molars, participated in the study.Materials and Methods:The following clinical measurements were recorded at baseline as well as three and six months post surgery: The Turesky-Gilmore-Glickman modification of the Quigley Hein plaque index, the Loe and Silness gingival index, Relative Clinical Attachment Level Vertical Probing Depth in the mid-furcation area, and Horizontal Probing Depth in the mid-furcation area.Statistical analysis:Pairwise comparisons within the groups were done by applying the independent student t test. Comparisons were also drawn between the test and the control groups by applying the independent student t test.Results:The mean gain in the relative clinical attachment levels in the test and control groups, at the end of six months, were 2.50 and 1.63 mm, respectively. The mean change in the horizontal probing depth values at the end of six months in the test and control groups were 2.88 and 1.63 mm, respectively. The mean reduction in the vertical probing depth values in the test and control groups were 1.50 and 1.38 mm, respectively.Conclusions:The resorbable GTR membrane with bone material was more effective than open debridement alone, in the treatment of furcation defects.