Abstract
Ultrasonic or sonic scalers may be the instruments of choice for effective debridement and reduction of operating time. A sonic scaler is as effective for debridement as an ultrasonic scaler. The aim of this study was to compare calculus removal time and dentin surface alterations (damage to the dentin surface) between a new sonic scaler and an ordinary sonic scaler. The new sonic scaler (HS) was operated at high frequencies ranging between 16,000 and 17,000 Hz and the ordinary sonic scaler (AS) at low frequencies ranging between 6,000 and 7,000 Hz.
The calculus removal time was recorded as the time required for complete removal of artificial calculus (n=14). Dentin surface alterations were compared between a control site and test sites that were treated for 20 seconds with the HS or the AS. The surface alterations were examined by SEM and the roughness of dentin surfaces (arithmetical mean deviation of the profile : Ra, and ten point high of irregularities : Rz) was measured (n=6). The calculus removal time was 514±103s for the HS and 546±191s for the AS, the difference being non-significant. Comparison with the control site showed that both the HS and the AS effectively reduced the smear layer without damage to the dentin surface. Ra was 0.82±0.08, 0.77±0.08, and 0.81±0.65 μm for the control, HS, and AS, respectively, and Rz was 3.69±2.53, 3.52±2.34, and 3.53±9.30 μm, respectively, the differences being non-significant. The HS was operated at the high end of the frequency range, which may have decreased the tip movement to 1/3 that of an ordinary sonic scaler. As a result, the operator was exposed to a clearly lower level of uncomfortable sound and vibration during debridement, and the new sonic scaler appeared to give results similar to those of an ordinary sonic scaler.
