[Friction sound as an objective sign of completion of root planing].

Root planing is one of the most important procedures in periodontal treatment. However, there are no objective clinical signs to indicate completion of this procedure. The purpose of this study was to examine the friction sound produced by curettes and root surfaces during root planing and to test the possibility of utilizing the sound changes as an objective parameter for evaluating completion of the procedure. The study consisted of a clinical and laboratory experiment. Seven periodontally diseased teeth were utilized in the clinical trial. During scaling and root planing with the Gracey curette, the friction sound was clinically analyzed with a sound spectrograph. The root surface, in situ, was observed by scanning electron microscopy (SEM) with the replica technique. Twenty-one periodontally diseased teeth were used in the laboratory study. Root planed surfaces were classified as pre-root planed and post-root planed according to their friction sounds during root planing. Each surface was examined by the following methods: 1) measuring root surface roughness 2) SEM observations 3) determination of number of adherent cells by the cultured fibroblast technique. As a result, post-root planed surfaces were well root planed as evaluated by SEM observations and the profilometer. Similarly, adherent cell counts were increased on post-root planed surfaces. These results indicated the possible usefulness of friction sound analysis to judge the completion of root planing.