SHARPENING OF ULTRASONIC SCALERS

Instruments suitable for removing calculus, plaque and necrotic cementum, which hinder normal periodontal reattachment, are extremely important for successful therapy. The test was carried out in order to see if a standard scaler used for ultrasonic tartar removal maintains its physical features when sharpened. 6 scalers, compatible with piezo-electric generators, were tested and 2 diameters, A and B, weights and resonance frequencies were measured. Scalers no. 2, 3, 4, 5, were sharpened with India stone, scaler no. 6 with rotatory instrument; scaler no. 1 was not sharpened and was used as control. All measurements were taken again at the end of the test. Statistical analysis reveals significant variations, after sharpening, of A diameter (t = 4.14 > 3.55, p < 0.01), B diameter (t = 5.34 > 3.355, p < 0.01) and resonance frequency (t = 2.82 > 2.306, p < 0.05); in contrast, there is no significant change of weights (t = 1.17 < 2.306, p > 0.05). These results suggest that sharpening slightly modifies the physical features of ultrasonic tips, so that sharpening ultrasonic scalers, from a physical point of view, can be carried out, paying attention not to damage the water cooling system.