An investigation of accessory foramina in furcation areas of human primary molars: Part 1. SEM observations of frequency, size and location of accessory foramina in the internal and external furcation areas.

Although the existence of accessory foramina in the furcation area and roots of permanent teeth has been demonstrated, the presence of accessory foramina in furcation areas of primary molars is less certain. This investigation was conducted to determine the presence or absence of accessory foramina in the furcation areas of human primary molars using the scanning electron microscope (SEM). Twenty extracted, carious and noncarious human primary molars were placed in fixative and then mounted in a hard tissue cutting machine: ten teeth were cut transversely 2.0mm coronal to the floor of the pulpal chamber and ten teeth were cut transversely 2.0mm apical to the external furcation. Both the internal and external furcation surfaces of these sectioned molars were debrided with sodium hypochlorite/hydrogen peroxide solutions to remove organic materials, which might obscure visibility of possible foramina and then rinsed in water and dried. The tissues were then prepared for and examined by SEM. Twenty percent of the molars examined by SEM on the internal furcation surface and 50% of the molars examined by SEM on the external furcation surface demonstrated accessory foramina.