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BACKGROUND A novel device, Ultrasonic Gracey Tip, reportedly combines benefits of a piezoelectric device and manual curette. The primary objective of this study was to compare root surface roughness outcomes between traditional manual curettes and piezoelectric devices, as compared to this novel device. The secondary aim was to assess the level of adhesion of Streptococcus mutans on the root surface after instrumentation. MATERIALS AND METHODS The groups consisted of 1) Gracey curette; 2) Piezoelectric scaler; 3) Ultrasonic Gracey Tip; and 4) untreated control. Root specimens were obtained from extracted human teeth and randomly assigned to each group. Surface roughness measurements (Ra and Rz) were taken with a profilometer before and after instrumentation. After instrumentation, root specimens were inoculated with S. mutans and biofilm was dislodged. Various dilutions of resuspended biofilm were incubated on blood agar plates and colony forming units (CFU) values were measured. RESULTS The experimental device resulted in significantly lower Ra and Rz compared to other groups (p<0.01), and the Gracey curette was significantly lower than the piezoelectric tip and untreated control (p<0.05). The Gracey curette and experimental device tip had significantly lower CFU values compared to the control (p<0.05). There were no significant CFU value differences between the Gracey curette and both the piezoelectric and experimental device tips. There were no significant CFU differences between piezoelectric tip and both experimental device and control. There was no correlation between Ra and CFU values for Gracey curette, piezoelectric tip, or the control. However, correlation between Ra values and CFU approached significance for the experimental device (correlation = 0.66, p = 0.05). CONCLUSIONS Ultrasonic Gracey Tip is effective at resulting in a significantly smoother surface compared to traditional piezoelectric and hand instruments. CFU values with Ultrasonic Gracey Tip were significantly lower than non-instrumented surfaces, but there were no significant differences compared to conventional methods. This article is protected by copyright. All rights reserved.