Scanning electron microscopic investigation of incidence, location, and size of accessory foramina in primary and permanent molars

Abstract

Objective: The purpose of this study was to determine and compare the incidence, location, and size of accessory foramina in the furcation region of permanent and primary molars.

Method and materials: A random sample of 100 extracted human permanent maxillary and mandibular first and second molars (25 teeth of each type) and a random sample of 100 extracted human primary maxillary and mandibular molars (50 teeth of each type) were used. The crowns and roots of each tooth were removed at a point 1.5 mm apical to the external furcation region, and a second cut was made at a point 1 mm apical to the cementoenamel junction. The specimens were examined using scanning electron microscopy at magnifications ranging from x 10 to x 1,250. The incidence, location, and size of accessory foramina were documented and statistically analyzed.

Results: Of the 100 permanent molars examined, 79% had accessory foramina with diameters ranging from 10 microm to 200 microm. Accessory foramina were present in 94% of the primary molars, with diameters varying from 10 microm to 360 microm. The incidence of accessory foramina was significantly higher in primary than in permanent molars.

Conclusion: The presence of accessory foramina with large diameters may imply that an inflammatory process can spread from pulpal to periodontal tissues and vice versa.