The interrelationship of pulp and periodontal disease

Abstract

In order to ascertain whether or not a relationship exists between periodontal and pulpal lesions, eighty-five teeth with periodontal lesions were examined histologically. Prior to extraction, subjective symptoms and the results of clinical tests were recorded. In addition, a medical and dental history was elicited. In many teeth a profusion of lateral and accessory canals and foramina were found, especially in the bifurcation and trifurcation regions of molars. Where the roots were fused with cementum, accessory canals were frequently seen. The pulps of only five teeth (6 per cent) were found to be uninvolved. Atrophic pulps were found in twenty-three teeth (27 per cent). The pulps were inflamed in forty-two teeth (49 per cent) and totally necrotic in fifteen teeth (18 per cent). These observations appeared to indicate that periodontal lesions produced a degenerative effect on the pulps of the involved teeth. In order to separate the effects of caries or operative procedures in the pulps of those teeth with periodontal involvements, we examined thirty-two periodontally involved teeth in which there was no evidence of caries or restorations. Among this group, twelve teeth (37 per cent) had pulps exhibiting various degrees of atrophy and twelve teeth (37 per cent) had inflammatory pulp lesions. In three teeth the pulps were completely necrotic. Further analyses indicated that pulps subjected to a combination of pulp and periodontal irritants showed a greater incidence of inflammatory reactions than those subjected to operative procedures alone. Pulp lesions were found to have an effect on the severity of the periodontal lesion. Inflammation of the periodontal membranes from inflamed and necrotic pulps was readily spread through lateral canals and accessory foramina, especially in molars. Also, extensive apical granulomas caused resorption of the crest of the interradicular alveolar ridge. Thus, retention of these teeth could be accomplished only through combined endodontic and periodontal therapy. Pain in periodontally involved teeth was also investigated. Atrophy or inflammation of the pulp was responsible for the greatest incidence of pain. The pain incidence appeared to increase when caries or restorations were present. Thermal responses in teeth with periodontal lesions increased significantly when the pulps were found to be inflamed, but there was no correlation between the type of pulp inflammation and a specific thermal test. The patients' complaints relating to pain on thermal stimuli were not found to be reliable indicators of the state of the pulp in periodontally involved teeth.