Spectrophotometric Evaluation of the Color Stability of Nanofilled Composites With and Without a Dentin Bonding Agent as a Surface Sealer Following Exposure to Common Beverages

Objective: The aim of this study is to evaluate the color stability of nanofilled composites with and without the application of a dentin bonding agent (Single Bond Universal Adhesive) as a surface sealer, following exposure to common beverages.

Methods: Eighty specimen disks of a nanofilled composite (Filtek 350XT) were prepared and divided into two groups: one treated without a composite sealer (Group A) and one with a composite sealer (Single Bond Universal Adhesive) (Group B). Each group was subdivided into four subgroups (subgroups A1, A2, A3, and A4 and subgroups B1, B2, B3, and B4), and each subgroup was immersed in a separate container containing coffee, tea, cola, or distilled water for 15 days. Color changes (ΔE) were measured using a spectrophotometer at baseline and after 15 days. Statistical analysis was performed using one-way analysis of variance (ANOVA) followed by Tukey's honestly significant difference (HSD) test.

Results: Statistically significant differences in color stability were observed between the sealed and unsealed groups. Specimens without sealant (subgroups A1, A2, and A3) showed greater color changes compared to sealed specimens (subgroups B1, B2, and B3). Coffee caused the greatest color change (ΔE = 30.31 for A1 vs. 12.00 for B1), followed by tea and then cola. Control groups immersed in distilled water showed minimal color change, which was not statistically significant (p > 0.05).

Conclusions: The results suggest that applying Single Bond Universal Adhesive as a composite sealer significantly reduces discoloration of nanofilled composites when immersed in coffee, tea, and cola over a 15-day in vitro period. Further research is needed to explore its long-term efficacy.