Comparative Effects of Different Abrasives on Surface Roughness of Dental Materials: An In Vitro Study

Surface roughness is a critical factor in restorative dentistry, as it influences both the esthetic and functional outcomes of dental materials. The choice of abrasive powders used during the air polishing of dental restorations can significantly impact the surface roughness, potentially affecting the longevity and performance of the restoration. This study aimed to compare the effects of three different air-polishing powders-sodium bicarbonate, erythritol, and glycine-on the surface roughness of a 3M Filtek (TM) Supreme XTE (3M St. Paul, Minnesota 55144-1000) United States composite resin and a Fuji (TM) IX glass ionomer cement. This study also examined how different application times (5 and 10 s) influenced these outcomes. Materials and Methods: An in vitro study was conducted using standardized blocks of 3M Filtek (TM) Supreme XTE composite resin and Fuji (TM) IX glass ionomer cement. Each material was treated with sodium bicarbonate, erythritol, and glycine at two different exposure times (5 s and 10 s) using a professional air-polishing device. Surface roughness (Ra) was measured before and after the treatments using a contact profilometer. The data were statistically analyzed using ANOVA and Tukey's post hoc test to compare the mean roughness values among the different groups, with a significance level set at p < 0.05. Results: The results showed significant differences in surface roughness between the materials, powders, and application times. The composite resin exhibited lower roughness and variability compared with the Fuji (TM) IX, indicating a more uniform and predictable surface. Sodium bicarbonate produced the highest roughness values, particularly after 10 s of application, while glycine resulted in the lowest roughness with greater variability. Erythritol produced intermediate roughness with moderate variability. For the Fuji (TM) IX, sodium bicarbonate caused the greatest variability in roughness, while glycine produced the smoothest surfaces. The ANOVA results confirmed significant differences in mean roughness among the abrasive groups, with Tukey's post hoc test showing that glycine had significantly lower roughness than sodium bicarbonate, and erythritol had higher roughness than glycine but was lower than sodium bicarbonate. Conclusions: This study demonstrated that the choice of air-polishing powder and application time significantly affected the surface roughness of both 3M Filtek (TM) Supreme XTE composite resin and Fuji (TM) IX glass ionomer cement. Glycine consistently produced the smoothest surfaces, making it a preferable option for clinical scenarios where minimal surface roughness is desired. Sodium bicarbonate, while effective in cleaning, resulted in rougher surfaces, particularly after longer exposure times. These findings suggest that careful selection of polishing powders can enhance the esthetic and functional outcomes of dental restorations, contributing to their longevity.