Brushing With Charcoal Toothpastes on the Surface Properties of a Giomer: A Comparative In-Vitro Study

Objective This study aimed to quantify changes in the microhardness (VHN) and roughness (Ra) in three esthetic restorative materials: a giomer, a universal nano-hybrid, and a nano-filled composite after one and six months of simulated brushing with various types of charcoal-containing toothpastes. Materials and methods Forty specimens (8 mm x 8 mm x 2mm) of each material were fabricated using the manufacturer's instructions and randomized into five groups. Baseline VHN and Ra readings were taken. Simulated brushing took place with four charcoal-containing toothpastes. A non-charcoal-containing toothpaste was used as a positive control. VHN and Ra were then measured after one month and six months of simulated brushing. Statistical analysis was performed using a two-way repeated-measure ANOVA to assess whether the factors of time, toothpaste, or the interaction produced significant changes in VHN and Ra. Post-hoc Bonferroni tests were used for pairwise comparisons of material properties brushed with the various toothpastes. Results All tested materials demonstrated a general trend of increasing microhardness and decreasing roughness, or roughness that was not statistically significant from baseline. Interaction of time*toothpaste produced statistically significantly higher microhardness values for the giomer (p=0.003) and nanohybrid (p=0.023) materials. The roughness of the nanofilled material was significantly lower than baseline, with the interaction of time*toothpaste (p=0.014). Conclusion The factors of time, toothpaste, or the interaction of time and toothpaste produced significantly different Ra and VHN values; however, variations in the properties were deemed favorable.