Prediction of root surface caries in patients treated for advanced periodontal disease

The present investigation was undertaken (1) to analyze the prevalence of root surface caries prior to and after periodontal treatment and (2) to determine the feasibility of using simple clinical criteria for predicting a patient's risk of developing root surface caries following periodontal therapy. Thirty-one patients were given advanced periodontal treatment including periodontal surgery. At baseline they were examined for oral hygiene status, root surface caries experience and number of lactobacilli per ml saliva as evaluated by the Dentocult dip-slide method. Follow-up examinations 1, 2 and 4 years after baseline showed that a majority of the patients were treated successfully and maintained in periodontal health. Root surface caries developed in approximately two-thirds of the patients during the 4-year observation period. However, the total increment of root lesions during these years was mostly extremely low, i.e. less than 5% of exposed root surfaces. In higher risk patients developing new root surface caries, significant correlations were demonstrated with initial pretreatment scorings from (1) their previous root surface caries experience, (2) high lactobacillus counts and (3) advancing age. In addition, root surface caries incidence and low saliva secretion rats were found to correlate significantly during the course of the study.