Investigation of the Color Change on Nano-Hybrid Composite Resin Caused by Non-Hydrogen Peroxide Whitening Mouthwashes

Objectives: This study aimed to examine the color change on nano-hybrid composite resin caused by non-peroxide whitening mouthrinses.

Materials and Methods: A nano-hybrid composite resin (shade A3) was used to prepare fifty disc-shaped specimens (8 mm in diameter and 2 mm in thickness) using a custom-made PTFE mold. Polymerization was performed with an LED light-curing unit according to the manufacturer’s instructions, applying light for 20 seconds on each side. The specimens were then stored in distilled water at 37 °C for 24 hours. Subsequently, they were randomly assigned into five subgroups (n = 10): four experimental groups treated with whitening mouthrinses (Listerine Advanced White [LAW], Colgate Optic White [COW], Colgate Plax White Charcoal [CPWC], Splat White Plus [SWP]) and one control group (distilled water). Color measurements were performed at baseline (T0) and after a 4-week mouthrinse regimen (T1) using a spectrophotometer (VITA Easyshade Compact, VITA Zahnfabrik, Bad Säckingen, Germany) based on the CIELAB system. Color difference (ΔE00) and whiteness index difference (ΔWID) values were calculated.

Results: Significant differences were found among groups (p<0.05). All experimental groups exhibited perceptible color changes (Δ E 00>0.8), while LAW, COW, CPWC, and SWP exceeded the acceptability threshold (Δ E 00>1.8). SWP demonstrated the highest color and whiteness change, showing statistically significant differences from other groups (p<0.05).

Conclusion: Non-peroxide whitening mouthrinses caused clinically acceptable color changes on nano-hybrid composite resin. SWP, which contains bromelain, exhibited the highest whitening effect.