Osteodentin formation in continuously erupting teeth of guinea pigs.

Osteodentin formation in guinea pig teeth was studied using in vivo microscopic and histologic techniques. The coronal half of both incisors and molars contained varying amounts of osteodentin. Within the osteodentin, narrow canals that contained pulp tissue were observed. Serial histologic sections demonstrated that these canals opened to the occlusal surface thereby exposing the pulp to the oral cavity.