A case is presented of extreme loss of tooth substance, most probably as a result of dentifrice abrasion. The lesions resulted in many instances of pulpal death and periapical pathosis. In most instances, an opening into the pulp chamber could not be demonstrated using an explorer. In two instances, an opening into the pulp chamber was present and probable. This communication with the oral cavity resulted in pulpal pathosis and an accompanying periapical lesion. In most cases of dental abrasion and erosion, or both, pulpal pathosis and periapical pathosis do not occur because of the ability of the pulp to lay down dentin as the pulp recedes. The findings in this case are not typical.