Microscopic studies of accessory canals in primary molar furcations.

The purpose of this study was to evaluate the incidence of accessory canals in the furcation region of human primary second molars. Forty freshly extracted teeth were radectomized and furcations were separated. The severed pulp chamber floors were decalcified and dehydrated. Paraffin embedding followed and cross-cut serial sections were taken from the specimens. Microscopic examination of each section followed. Sixteen out of twenty (80 percent) of the maxillary and fifteen out of twenty (75 percent) of the mandibular primary second molars demonstrated accessory foramina in the furcation area. 17.3 percent of the accessory foramina were found in the pulp chamber floor and 82. 7 percent were observed interradicular, close to the periodontal ligament. Thirty percent of the primary second molars demonstrated accessory canals, running from the pulp chamber to the periodontal ligament. Within the limitations of a microscopic investigation it is assumed that accessory furcation canals might be responsible for interradicular bone pathology in case of pulpal inflammation or necrosis.