A comparative study of conventional and modified instrument design in periodontal therapy

Purpose: The present study was designed to evaluate and compare the efficacy of Slimline ultrasonic inserts with hand instruments in removing subgingival calculus. The topography of root surfaces was also studied using Scanning Electron Microscope following instrumentation. Methods: A sample of 36 posterior teeth, scheduled for extraction, were obtained following instrumentation, from patients with advanced periodontal disease. Twelve teeth in each group were instrumented up to the depth of the pocket and were categorized based on the instrument used: Group A - Gracey curette 11/12 and 13/14, Group B - Gracey curette 15/16 and 17/18, and Group C - Ultrasonic Slimline inserts. The extracted teeth were later subjected to stereomicroscopic examination and SEM analysis. Results: The percentage of surface area covered by residual calculus ranged from 21%- 32% and 22%-32% for Group A, 20%-29% and 22%-30% for Group B, and 18%-26% and 19%-26% for Group C, for mesial and distal surfaces respectively. A statistically significant difference was noted for percentage of surface area covered by residual calculus between the three groups (p ≤ 0.001). Conclusion: The amount of residual calculus present was least with the use of ultrasonic Slimline inserts compared to Gracey curettes 11/12 & 13/14 and Gracey curettes 15/16 &17/18. However, the difference between the two groups of Gracey curettes was not significant. The results suggest that the usage of ultrasonic scalers with Slimline inserts during subgingival scaling and root planing would prove more effective than using either of the hand instruments alone.