Toothbrush bristle type and toothpaste effect on surface gloss and microstructure of resin composites and zirconia

Surface gloss plays a critical role in the esthetics and longevity of restorative dental materials, yet it is often compromised by toothbrushing variables. This in vitro study evaluated the effect of toothbrush bristle type and toothpaste formulation on the gloss and microstructure of resin composites and zirconia fabricated through additive and subtractive techniques. Results revealed that additively manufactured zirconia exhibited the highest initial gloss and the greatest resistance to gloss loss and microstructural defects, while subtractively manufactured resin composites showed the most significant deterioration. Round-end bristles combined with whitening toothpaste produced the greatest reduction in gloss and the largest defect volumes across all materials. These findings emphasize that material selection and oral hygiene regimen are critical to maintaining the esthetic and structural integrity of restorations.