This paper evaluates the use of guided tissue regeneration for treating 19 pairs of molar grade II furcation defects. Presurgical measurements were taken for the determination of aveolar crestal resorption, vertical open probing attachment, and horizontal open probing attachment. The surgical procedure consisted of sulcular incision, full-thickness facial and lingual flaps, soft tissue debridement, and root planing. One defect from each pair of furcas was treated with an expanded polytetrafluoroethylene membrane, which was left in place for 4 to 6 weeks. Postsurgery soft tissue measurements showed a reduction in probing depth and a gain in vertical and horizontal open probing attachment.