An Investigation of Accessory Canals in Furcation Areas of Human Primary Molars: Part 2. Latex Perfusion Studies of the Internal and External Furcation Areas to Demonstrate Accessory Canals

Four classes of accessory canals: "true," "blind," "looping" and "enclosed" canals have been suggested to exist in furcation areas of primary teeth. Although the existence of accessory canals in the furcation areas and roots of permanent teeth has been demonstrated, their presence in furcation areas of primary teeth is uncertain. This investigation was conducted to determine the presence or absence of accessory canals in the furcation areas of human primary molars using a variety of latex perfusion techniques. Twenty extracted, noncarious human primary molars were placed in fixative and then sectioned on a hard tissue cutting machine: ten teeth were cut transversely 2.0 mm coronal to the floor of the pulpal chamber and ten teeth were cut transversely 2.0 mm apical to the external furcation area. The internal and external furcation surfaces of these sectioned molars were debrided with sodium hypochlorite/hydrogen peroxide solutions, rinsed in water and dried to remove organic materials, which might obscure the existence of possible canals. Twenty of these extracted teeth were examined by SEM to detect the possible presence of accessory foramina in the internal and external furcation areas (Part 1). Twenty percent of the molars examined by SEM on the IFA and 50 percent of the molars examined by SEM on the EFA exhibited accessory foramina. Twenty molars were perfused with low viscosity latex using vacuum [negative] pressure (10 molars) and positive pressure (10 molars) to detect the possible existence of the patency and the extent of such accessory canals in the internal and external furcation areas (Part 2).(ABSTRACT TRUNCATED AT 250 WORDS)