Color improvement and surface integrity: Charcoal-based oral care products on stained resin composite.

Purpose: To determine the effect of charcoal-based toothpaste used alone or in combination with charcoal-based mouthwash on color change (ΔE₀ ₀) and surface roughness (Ra) of a stained resin composite.

Methods: Disc-shaped (8 x 2 mm) resin composite samples (Filtek Z250) were prepared. Then, the samples were immersed in coffee for 12 days. The samples were randomly assigned into four groups (n= 12). Distilled water (DW), Colgate Total 12 (CT), Colgate Optic White (COW), and Colgate Optic White + Colgate Plax White Charcoal (COW + CPWC) were used over a 3-month period. Color measurements were performed at baseline, after staining, after 1 and 3 months use. Ra analysis and surface topography by scanning electron microscopy (SEM) were evaluated after staining, after 1 and 3 months use.

Results: Color changes occurring on resin composite samples immersed in coffee for 12 days exceeded the 50:50% acceptability threshold (AT) (ΔE₀ ₀:1.8). CT, COW, and COW + CPWC reduced the color change on composite samples below to the AT after 3 months of use. CT and COW + CPWC showed a significant increase in Ra after both time intervals and caused changes in surface morphology of resin composite. The present findings suggest that charcoal-based toothpaste used alone may be effective in improving the color of resin composite without inducing surface damage. Moreover, when used with charcoal-based mouthwash, the similar effect in color improvement may be accompanied by increased surface roughness.

Clinical significance: This is the first study evaluating the effect of charcoal-based mouthwash when used with charcoal-based toothpaste on color change and surface roughness of a stained resin composite. Both toothpastes tested were effective in improving the color of the resin composite samples. While conventional toothpaste caused increased surface roughness, the charcoal-based toothpaste maintained surface integrity. However, charcoal-based toothpaste did not provide further color improvement when used in combination with the charcoal-based mouthwash and specifically led to increased surface roughness, highlighting potential implications for clinical practice.