BACKGROUND Cervical enamel projections (CEPs) have been listed among the tooth-associated risk factors that could lead to isolated furcation defects around molar teeth. This is more likely when Grade III CEPs are present. However, the histologic aspects of the CEP interface with regard to the presence or absence of cementum over the enamel projection within the furcation have not been well described. This study was initially undertaken to evaluate this relationship. METHODS Thirty-five mandibular molars with Grade III CEPs were selected from a collection of extracted teeth and evaluated for the presence of cementum covering these areas by stereomicroscopy, light microscopy, and scanning electron microscopy (SEM). RESULTS Sixteen of the 35 teeth (45.7%) with Grade III CEPs appeared completely covered by cementum. SEM evaluation showed the presence of a narrow pouch-like opening between cementum and enamel in 15 of 16 teeth (93.8%). Light microscopy evaluation confirmed the presence of the pouch along with some indication of residual degenerated mesenchymal tissue within the defects. SEM evaluation showed the presence of globular bodies in this pouch. CONCLUSIONS This study reports on the presence of a pouch-like opening between the enamel and cementum in mandibular molars with Grade III CEPs. The clinical significance of these cementum pouches has yet to be determined but bacterial contamination of these pouch-like structures in areas of furcation periodontal breakdown may serve as a nidus for recolonization and disease recurrence or for the development of furcation caries if exposed to the oral cavity after surgical procedures.