Effects of air-polishing powders on color stability of composite resins

objectives: the purpose of this study was to investigate the effect of different air-polishing powders on the color stability of different types of composite resin restorative materials. material and methods: thirty cylindrical specimens (15×2 mm) were prepared for each of 7 composite resin restorative materials. all specimens were polished with a series of aluminum oxide polishing discs (sof-lex). the prepared specimens of each composite resin were randomly divided into 3 groups of 10 specimens each, for control (group-c) and two air-powder applications (group-cp: cavitron prophy-jet; group-ps: sirona prosmile prophylaxis powder). a standard air-polishing unit (prosmile handly) was used. all specimens were air-powdered for 10 s at 4-bar pressure. the distance of the spray nosel from the specimens was approximately 10 mm and angulation of the nosel was 90°. specimens were stored in 100 ml of coffee (nescafe classic) for 24 h at 37°c. color measurement of all specimens was recorded before and after exposure to staining agent with a colorimeter (minolta cr-300). color differences (？e*) between the 2 color measurements (baseline and after 24 h storage) were calculated. the data were analyzed with a 2-way anova test, and mean values were compared by the tukey hsd test (p<0.05). results: according to the 2-way anova results, composite resin restorative materials, air-polishing powders, and their interaction were statistically significant (p<0.05) for aelite aesthetic enemal, filtek z250, grandio, ceramx mono, and quixfil composite resin restorative materials, no significant difference was observed between group-ps and group-cp (p>.05) and these groups demonstrated the highest ？e* values. for filtek silorane and intens, the highest ？e* values were observed in group-ps. the lowest ？e* values for all composite resin groups were observed in group-c. when comparing the 7 composite resin restorative materials, aelite aesthetic enemal demonstrated significantly less ？e* values