Calculus removal from multirooted teeth with and without surgical access. II. Comparison between external and furcation surfaces and effect of furcation entrance width.

The purpose of this study was to evaluate the effect of furcation entrance width on the efficacy of calculus removal from furcation areas as well as to compare this efficacy between external and furcation surfaces after closed root planing, open root planing and use of a rotary diamond for the furcation area. 30 first and second lower molars scheduled for extraction with a calculus index > or = 2 and a degree II or III furcation involvement were divided into 3 groups: 10 molars were scaled and root planed using a closed approach: 10 molars were scaled and root planed using an open approach; 10 molars were scaled and root planed with an open approach and rotary diamond was used for removal of deposits in the furcation area. After extraction, the width of the furcation entrance was measured buccally and lingually 2 mm apical from the bifurcation and furcations were categorized as wide (width > 2.4 mm) or narrow (width < 2.4 mm). The teeth were assessed in a stereomicroscope and the % of residual calculus on external and furcation surfaces was calculated. The width of the furcation entrance influenced the efficacy in root planning in the open group (p = 0.0015). The use of rotary diamond was the most effective method for removing calculus both for narrow and wide furcations. The effectiveness of open root planning in the mesial root was related to the width of the furcation entrance where the % of residual calculus was significantly higher for narrow furcations (p = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)