In vitro evaluation of novel low abrasive air polishing powders

Aim of the study: Though efficient in stain and plaque removal, air polishing is highly abrasive on root cementum or dentin even if working parameters are adjusted to minimize damage. As abrasiveness is also influenced by the physical properties of the powders used, the aim of the study was to evaluate the safety of novel low abrasive air polishing powders in vitro. Material and methods: Using four novel air polishing powders (A, B, C and D) and a standard sodium bicarbonate (NaHCO3) powder, roots of 126 extracted teeth were air polished under standardized conditions at various working parameter combinations (distance: 2mm, 4mm and 6mm; powder and water setting: low, medium and high) at an angulation of 90degrees for 20s. Instrumentation was performed in triplicate; resulting root defects were quantified laser-optically. Results: Mean defect depths after application of powders A, B, C and D were significantly lower than with standard powder (A: 17.9 +/- 10.9 mum, B: 48.2 +/- 32.7 mum, C: 92.5 +/- 57.9 mum, D: 33.9 +/- 19.6 mum, NaHCO3: 163.1 +/- 71.1 mum) (Kruskal-Wallis test). Among the experimental powders, D was transported most reliably in the air polishing unit and allowed complete removal of disclosed plaque as assessed on freshly extracted teeth. Conclusion: The novel air polishing powder D is of low abrasiveness to root cementum and dentin while being effective in removing dental plaque. Thus, it may be useful for safe and efficient plaque removal on exposed root surfaces.