Abstract: Objective  To investigate the effects of air-abrasion parameters, including pressure, distance, and angle on the abrasive efficacy and extrinsic stain removal effect of chloride-containing bioactive glass abrasives (Cl-BG). Methods  With commonly used abrasive sodium bicarbonate (NaHCO3) as the control, the particle size and morphology of Cl-BG were characterized using a laser particle size analyzer and scanning electron microscope (SEM), and their cytotoxicity was evaluated with a CCK-8 assay. The enamel removal volume on bovine enamel by Cl-BG under different air-abrasion parameters (pressure: 20, 40, 60 psi; distance: 2, 5 mm; angle: 45°, 90°) was quantitatively analyzed using a white light interferometry. An extrinsic stain model on extracted human teeth was established, and the stain removal effects of the two abrasives under set parameters were visually observed using stereomicroscopy and SEM. Results  Cl-BG and NaHCO3 had similar particle sizes and both showed no cytotoxicity. The enamel removal volume by Cl-BG increased with increasing air-abrasion pressure, while the influences of the angle and distance were less significant. Under identical parameters, the stain removal effect of Cl-BG was superior to that of the NaHCO3. Within the Cl-BG group, the removal efficiency at a 90° angle was  found to be superior to than at 45°. SEM observations revealed the presence of residual glass particles on the enamel surface after treatment, providing a potential remineralization ability. Conclusion  Air-abrasion efficacy is primarily regulated by pressure. It demonstrated that Cl-BG was an effective agent for the removal of  dental extrinsic stains. The good biocompatibility and the potential to promote remineralization made it a highly promising novel abrasive for minimally invasive dentistry.

Key words: chlorine-containing bioactive glass, air abrasion, extrinsic dental stains, enamel abrasion, air-abrasion parameter, sodium bicarbonate