Comparative Evaluation of Tea, Coffee, and Cold Drink Staining on Nanofilled Composite Restorations and Their Color Recovery after Tooth Whitening

Abstract

Background: Resin-based composites used in restorative dental procedures are susceptible to discoloration when in contact with common beverages. The esthetic effect of this discoloration is still of concern. Recent studies have shown that the nanofilled composites discolor when in contact with tea, coffee and cold carbonated beverages. The degree of discoloration is difficult to reverse with tooth whitening. Thus, this study aims to evaluate the staining potential of tea, coffee and cold carbonated beverages on nanofilled composites as well as the degree to which tooth whitening is able to restore the color of these stains.

Objective: To investigate the potential of tea, coffee, and cold carbonated drinks to stain nanofilled composites and the ability of a standard tooth-whitening procedure to restore color to the stained composites.

Methods: This in-vitro study consisted of 60 standardized nanofilled composite resin specimens, divided into three groups: beverage exposure groups for tea (n=20), coffee (n=20), and carbonated cold drink (n=20). Standardized molds were used to prepare all specimens which were polymerized as per the manufacturer’s instructions. Simple random sampling/allocation used to place specimens into the different groups. As the study if based in a laboratory and involves the use of composite specimens instead of human subjects, the age of participants was not relevant. Baseline and values obtained post exposure to the three beverages, measured using a digital spectrophotometer and the CIELAB color system. The calculation of overall color difference (ΔE) were done post exposure. All specimens were subjected to a standardized tooth whitening procedure using a commercially available whitening agent. Post whitening, color measurements were done to assess percentage color recovery.The values were recorded in a data collection proforma as group type, specimen ID, baseline and post exposure (staining and whitening) L*, a*, b* values, and calculation of ΔE and percentage color recovery. Statistical analysis was performed to analyze ΔE and percentage color recovery for all three groups in relation to color changes and recovery.

Results: Nanofilled composite restorations were discolored after being exposed to tea, coffee, and carbonated cold drinks. Coffee, and to an even greater extent, tea to discolor more as they both contain a greater amount of chromogenic compounds. Whitening procedure recovered color but partial and varied. ΔE values determined the effectiveness of the whitening procedure in removing discoloration caused by beverages.

Conclusion: The study added modern comparative data on the susceptibility of nanofilled composite restorations to staining by tea, coffee, and carbonated cold drinks, as well as the ability of tooth whitening to revert these restorations to their original color. The results should help dentists in explaining to their patients the interaction between beverage consumption and the post-whitening appearance of nanofilled composite restorations.