In vitro analysis of the efficacy of ultrasonic scalers and a toothbrush for removing bacteria from resorbable blast material titanium disks

Background: A resorbable blast material (RBM) surface is reported to have a higher bone-to-implant contact percentage than machined surfaces, but modified surfaces with rougher textures have been shown to favor colonization by bacteria and development of peri-implantitis. Therefore, this in vitro study compares the effects of different instruments on surface roughness and removal of bacteria from RBM titanium implant disks. Methods: RBM titanium disks were treated with various ultrasonic scaler tips and a toothbrush, and change in surface roughness was measured by confocal microscopy. The disks were incubated with bacteria, and instruments made of carbon or plastic, two metal ultrasonic scaler tips, or a toothbrush were used to remove the attached bacteria. The amount of remaining bacteria was evaluated using a crystal violet assay. Results: The change in surface structure following different treatment modalities was analyzed by confocal microscopy. A statistically significant decrease in the arithmetic mean value of RBM surfaces (R_a) was observed after treatment with an ultrasonic scaler with a metal tip. The use of a metal tip (rather than a carbon or plastic tip) and brushing with dentifrice was more efficient in removing bacteria from the contaminated titanium surface according to the crystal violet assay. Conclusion: Within the limits of this study, the use of a metal tip may be effective in removing bacteria from contaminated surfaces.