Time-dependent effect of intense capsule-coffee and bleaching on the color of resin-infiltrated enamel white spot lesions: an in vitro study

BACKGROUND AND OBJECTIVES: White spot lesions (WSLs) are a common problem that can be conservatively managed by resin infiltration. Consumption of dark beverages such as coffee causes staining of dental hard tissues, which can deteriorate the esthetic qualities of treated WSLs. The aims of this study were to investigate the effect of dark coffee heavy consumption on ICON(®) resin infiltrated WSLs and the influence of bleaching on them after staining. METHODS: Twenty surfaces from sound human extracted third molars were used in the study. Two square-shaped buccal and lingual window areas had artificially created WSLs (received buccal resin infiltration afterward). Using VITA Easyshade, the baseline ΔE was recorded. Espresso coffee was used to immerse all surfaces for 8 days. The color coordinates according to CIE LAB were recorded for all surfaces at 2, 4, 6, and 8 days of immersion, and ΔE was calculated at each timepoint. After 8 days, in-office bleaching was applied to all surfaces according to the manufacturer’s instructions and the color. Coordinates and ΔE were recorded. For statistical analysis, an independent sample t-test was used to compare each group. A general linear mixed model (GLMM) repeated measure ANOVA was applied for statistical analysis of L(*)and changes due to staining over time. RESULTS: Analysis of time as a main effect on the L values of surfaces was statistically highly significant (p < 0.01). The interaction of time with surfaces under investigation and type of surface (test vs. control) as a main effect were non-significant (p = 0.47 and p = 0.35, respectively). Bleaching showed a significant difference in color lightness in both test and control surfaces compared to the mean L value at 8 days of staining (p < 0.01). CONCLUSION: Capsule-coffee consumption gradually influences the esthetic of resin infiltration on treated teeth. However, bleaching materials might restore an esthetic shade.