Root surface debridement and endotoxin removal

OBJECTIVE: This study assessed associations between the number of standardized scaling strokes and the reduction of endotoxin on the root surface. BACKGROUND: Therapy of periodontally involved teeth attempts removal of accretions by scaling and root planing. The amount of mechanical therapy required to free the root surface from etiologic factors remains unknown. METHODS: Twenty-four extracted human caries-free single rooted teeth with at least 5 mm attachment loss were used. A region of interest (ROI) which contained subgingival calculus was defined on the root surface of each tooth. Standardized force instrumentation was applied using a force-measuring curet. Fifty working strokes were applied to every ROI. Forces applied were recorded. The force recordings were converted from Millivolts into Newtons (N). After every unit of 5 strokes, presence of calculus was evaluated and scaling debris was collected. Endotoxin concentration was determined in the debris samples. RESULTS: The endotoxin values for strokes 1-5 were statistically significantly greater than the values from all other stroke intervals. Complete calculus removal occurred after a mean of 9.3 strokes. The endotoxin concentration reached a minimal level with concentrations of 0.03-0.306 EU/ml after calculus removal was complete. CONCLUSION: These findings suggest that completion of calculus removal coincides with endotoxin levels associated with clinically healthy teeth.