The topography of the furcation entrance in Chinese molars

Abstract The purpose of the present study was to document the furcation entrance dimensions (FEDs) of the maxillary and mandibular 1st and 2nd molars and relate them to the choice of periodontal therapy. Study samples consisted of 89 maxillary molars (49 1st and 40 2nd molars) and 93 mandibular molars (50 1st and 43 2nd molars). All the FEDs of the molars were examined and measured under a stereomicroscope at 2.5 × equipped with a Bioscan OPTIMAS Image Analyzer (BOIA). The results may be summarized as follows. (1) The mean FEDs in the buccal, distal and mesial furcations of maxillary 1 st and 2nd molars were 0.74 mm, 0.99 mm and 1.04 mm in the 1st molars, and 0.63 mm, 0.67 mm, 0.90 mm in the 2nd molars, respectively. In the buccal and lingual furcations of mandibular 1st and 2nd molars, they measured 0.88 mm and 0.81 mm, and 0.73 mm and 0.71 mm, respectively. (2) The %s of FEDs of 0.56 mm or less (the tip width of a Cavitron tip being 0.56 mm) in the buccal, distal and mesial furcations of maxillary 1st and 2nd molars, accounted for 32%, 8% and 6% of 1st molars, and 40%, 40% and 18% of 2nd molars. In the buccal and lingual areas of mandibular 1st and 2nd molars, they accounted for 16% and 26%, and 35% and 33% of the furcations, respectively. (3) The %s of FEDs of 0.75 mm or less (the width of curettes being 0.75–1.0 mm) in the buccal, mesial and distal furcations of maxillary 1st and 2nd molars accounted for 57%, 18% and 43% of 1st molar furcations, and 83%, 43% and 65% of 2nd molar furcations, respectively. In the buccal and lingual areas of mandibular 1st and 2nd molars, they accounted for 36% and 52%, and 63% and 61% of the furcations, respectively. (4) The majority of mean FEDs in 2nd molars were less than the blade width of new Gracey curettes, whereas in 1st molars they were similar to the blade width of unused Gracey curettes. (5) Most mean FEDs in 1st and 2nd molars were greater than the width of unused Cavitron tips. (6) To achieve complete debridement of root surfaces within furcations, an appropriate selection and combination of Cavitron tips and periodontal curettes should be considered.