Abrasiveness of Air-Abrasion Powders on a Luting Composite Resin
Objectives: The aim of this study was to test the effectiveness of Orthoprophy SA-85 Soft Alumina (Danville Materials, CA, USA), which is gentle on hard tooth substance, in the removal of luting composite resin in comparison to the conventional air-abrasion with 50 µm alumina powder.
Methods: Seventy-two composite discs made out of a luting composite resin (Panavia V5 brown; Kuraray, Japan) were produced and wrapped with thin foil in which a hole (2 mm diameter) was punched. At three different air-abrasion times (20 s, 40 s, 60 s) the volume removal by alumina and Orthoprophy was evaluated (n=12). The air-abrasion was performed at a pressure of 0.25 MPa with a distance of 2 mm to the surface. After air-abrasion the discs were scanned with a laboratory scanner (3Shape A/S D900, Denmark) and the removed volume was determined with the software GeomagicWrap (3D Systems, Germany). One-way ANOVA with a post-hoc Games-Howell test was used for the statistical analysis.
Results: For alumina air-abrasion the median of the removed volume ranged from 2.25 mm3(20s)to 6.18 mm3 (60s), while Orthoprophy showed a range from 0.45 mm3(20s)to 1.40 mm3 (60s). Orthoprophy produced a statistically significantly lower volume loss than alumina for all three air-abrasion times.
Conclusions: Orthoprophy is less effective in the removal of composite resin than conventional alumina particles. However, it still removes a considerable amount of composite resin. Because of the tooth substance preserving properties of this material it might be suitable clinically when removing remnants of luting resin from enamel.