Evolution of roughness and optical properties of resin composites submitted to whitening toothpastes-cigarette smoking cycling.

PURPOSE: To evaluate the effect of cycling whitening toothpaste with cigarette smoking (WTCS) on the evolution of roughness, color, translucency, and gloss of microfilled, microhybrid, and nanofilled resin composites. METHODS: 15 specimens of Durafill - DVS, Empress Direct - ED, and Z350 - FZ were divided into three groups according to the toothpastes:: conventional, control group, (Colgate - C) and Whitening (Colgate Luminous White - CW and Oral B 3D White - OW) and roughness, color, translucency, and gloss were evaluated before and after the specimens were submitted to WTCS for 8 weeks. Data were analyzed by two-way ANOVA, 3-way repeated measures ANOVA, and Tukey HSD post hoc test (α= 0.05). RESULTS: Only ED and FZ brushed with CW and FZ brushed with C presented an increase in roughness after WTCS. The three composites suffered a significant color alteration after WTCS. Excepting DVS brushed with CW, all the other groups presented a significant reduction in translucency after WTCS. DVS was the only resin composite that maintained its gloss stability after WTCS. Whitening toothpastes behaved similarly to conventional (control) toothpaste regarding the evolution of roughness and optical stability of the three resin composites. CLINICAL SIGNIFICANCE: Whitening toothpastes were not capable of maintaining the color stability of the three resin composites after 8 weeks of toothpastes-cigarette smoking cycling.

Antimicrobial potential of resin matrices loaded with coffee compounds.

This study evaluated the biological behavior of the coffee compounds Trigonelline (T), chlorogenic acid (C), and nicotinic acid (N), correlating with their release from a resin matrix. Minimum inhibitory concentration (MIC) was evaluated against Streptococcus mutans UA159, and cytotoxicity was assessed by methyl tetrazolium salt on OD-21 cells. Resin matrices (bisphenol A-glycidyl-dimethacrylate/triethylene glycol-dimethacrylate 70/30 wt%, camphorquinone/ethyl 4-dimethyl aminobenzoate 0.5/1 wt%) were doped with coffee compounds in different concentrations (10/20/30/40/50 wt%), performing 15 groups (T10-T50, C10-C50, N10-N50), and a control group with no coffee compound. Degree of conversion (DC%) was analyzed by Fourier transform infrared spectroscopy. Antimicrobial properties were evaluated by bioluminescence (Luciferase assay). The release from loaded matrices was analyzed over time (24 hr, 6, 14, 21 and 28 days), using high-performance liquid chromatography (HPLC). Data were submitted to ANOVA/Tukey's test (α = 0.05). MIC for T and C was 6 mg/ml, and 4 mg/ml for N. None of them were cytotoxic. Only T50 and C50 showed lower DC% than control (α < 0.05). Some groups (T30/T40/T50/C40/C50/N50) were strongly antimicrobial, reducing bacterial activity approximately five times compared to control (α < 0.05). For T30, T40, T50, C40, and C50, the HPLC showed a release above or closer to MIC values mainly in 24 hr, but for N50, up to 28 days. In conclusion, the coffee compounds presented antimicrobial activity, depending on their concentration when added in resin matrices, being found a correlation with their release.