Can charcoal-based dentifrices change the color stability and roughness of bleached tooth enamel and resin composites?

Background: Given the increasing prevalence of individuals using charcoal-based dentifrices over extended periods without professional oversight, concerns have emerged regarding their potential effects. This study aimed to investigate the influence of different charcoal-based products on color change (ΔE00), gloss stability, and surface roughness of dental enamel (Intact or bleached) and resin composites subjected to 12-month simulated brushing. Material and Methods: 132 bovine crowns were randomly allocated and restored with either SS-single-shade or conventional multi-shade, NH-nanohybrid, NF- nano-filled, or BF- bulk-fill composite. A conventional toothpaste (Control), a charcoal-based toothpaste (DC) , and a charcoal-based toothpowder (PO) were evaluated corresponding to 1-, 2-, 6-, and 12-month simulated tooth brushing, respectively. Color (ΔE00) and surface roughness (Ra) were assessed at baseline and after each brushing (n=11). Gloss (GU) was assessed before and after brushing. The brushing products, as well as the enamel and composite surfaces, were analyzed using scanning electron microscopy. Color change, gloss stability, and surface roughness were analyzed by a three-way repeated-measures analysis of variance followed by Tukey’s test (α=0.05). Results: Significant differences were found for composite color change (ΔE00) based on brushing product (P<0.001), brushing time (P<0.001), and their interaction (P<0.001), with similar changes across charcoal-based and conventional toothpaste. After 12 months of brushing with toothpowder (PO), all composites exceeded the acceptable ΔE00 threshold. Gloss values decreased significantly (P<0.001), with greater losses in NF and NH resins. Roughness (Ra) also increased more with PO than with toothpaste. Both PO and DC significantly reduced enamel gloss, especially on bleached enamel. Conclusions: Charcoal-based toothpaste alters the morphology, roughness, gloss, and color of enamel and resin composite, similar to regular toothpaste. Toothpowder creates surface irregularities, decreasing the gloss and increasing the color change and roughness, more strongly impacting bleached enamel and composites after 12-month simulated tooth brushing.