Long-term evaluation of root surface caries in periodontally treated patients.

Caries development on exposed root surfaces was evaluated in 31 patients who had been subjected to surgical and/or nonsurgical periodontal treatment 8 years earlier due to advanced chronic periodontitis. Besides assessments for evaluation of the periodontal treatment, a number of examinations and tests were carried out in order to assess variables presumed to influence the root surface caries development. Both statistical and graphical analyses were carried out to test differences between groups of subjects and to evaluate the variables studied as possible risk factors for root surface caries. The variables studied were: salivary lactobacillus count, salivary Streptococcus mutans count, plaque score, salivary secretion rate, salivary buffer effect, oral sugar clearance time, dietary habits and the age of the subject. The final results support previous findings from an initial 4-year period that root surface caries occurs, though to a minor extent, in this patient category demonstrating good or excellent periodontal conditions after periodontal treatment. A positive correlation was found between the baseline and final root surface caries scores. After the second 4-year period, the salivary counts of S. mutans and lactobacilli, the plaque score and the dietary habits differed significantly between groups of subjects who had developed 0 or greater than 5 new DFS %. Root surface caries was far more prevalent when risk values of the variables studied were present than when they were absent. The important variables in this respect differed considerably between the subjects. No single variable was found to be discriminative in all subjects.