Significant influence of scaler tip design on root substance loss resulting from ultrasonic scaling: a laserprofilometric in vitro study

Objectives: Ultrasonic scalers have become increasingly popular for subgingival debridement. The aim of the present study was to investigate the influence of different working tip designs (narrow versus wide) on root substance loss caused by either magnetostrictive or piezoelectric ultrasonic devices. Methods: In this in vitro study, a magnetostrictive ultrasonic system with either Slimline or TFI-10 inserts and a piezoelectric ultrasonic system with either Perioprobe or Type-A inserts were compared at different application forces. Loss of root dentin was determined by defect width, defect depth and defect volume resulting from standardized instrumentation using laser profilometry. Results: There were consistent and statistically significant differences between all groups. The mean observed dentin alterations for the magnetostrictive ultrasonic device operating a Slimline insert at a lateral force of 0.3 N were 254.4 mum, 6.3 mum and 22.5 mum(3) and for the TFI-10 tip 759.0 mum, 23.5 mum and 160.2 mum(3) for the parameters defect width, depth and volume, respectively. For the piezoelectric ultrasonic system operating a Perioprobe insert, the corresponding mean values were 352.0 mum/12.1 mum/56.4 mum(3) and for the universal Type-A insert they were 402.4 mum/14.0 mum/133.4 mum(3). With application forces of 0.7 N, root substance removal increased up to twofold. Conclusion: The present investigation could demonstrate that the aggressiveness of magnetostrictive and piezoelectric ultrasonic devices to root substance was significantly influenced by the scaler tip designs, increasing for wider scaler tips as compared with narrow, probe-shaped inserts.