Evaluation of sorption/solubility, softening, flexural strength and elastic modulus of experimental resin blends with chlorhexidine

ObjectivesTo evaluate physical-chemical properties of experimental diacetate chlorhexidine (CHX)-added resin blends.MethodsBlends were formulated: G1)TEGDMA; G2)TEGDMA/0.1%CHX; G3)TEGDMA/0.2%CHX; G4)TEGDMA/UDMA; G5)TEGDMA/UDMA/0.1%CHX; G6)TEGDMA/UDMA/0.2%CHX; G7)TEGDMA/BisEMA, G8)TEGDMA/BisEMA/0.1%CHX; G9)TEGDMA/BisEMA/0.2%CHX. Icon® was the control group. For sorption/solubility (SS), cylindrical specimens (n = 5) were prepared and their weight obtained. The specimens were immersed in deionized water for 7 days at 37 °C and their weight was verified again. SS were calculated using accepted formulas. For softening, cylindrical specimens (n = 10) were prepared and initial Knoop hardness number (KHN) obtained. The specimens were immersed in absolute ethanol for 24 h at 37 °C and final KHN accomplished. Softening values were calculated by KHN reduction percentage. For elastic modulus (EM) and flexural strength (FS) bar specimens were prepared (n = 10) and values obtained with a universal device (three point, 5 mm distance, 0.5 mm/min, load of 50 N). The data was analyzed using one-way ANOVA and Tukey test (α = 5%).ResultsTEGDMA/BisEMA blends and Icon® showed the lowest sorption from blends (p > 0.05), and Icon® was the most soluble material (p < 0.01). TEGDMA/UDMA/0.1%CHX showed the highest softening, similar to Icon® (p > 0.05). For EM, all blends were different than Icon® (p < 0.01). For FS, TEGDMA blends were similar to Icon®, showing the lowest averages (p > 0.05).ConclusionsMonomers chemical characteristics influenced the physical-chemical properties of experimental blends more than CHX. Between the blends tested, UDMA blends presented satisfactory results for assays evaluated.Clinical significanceInfiltrants CHX-added could arrest and reinforce initial caries lesions, and the antimicrobial effect could prevent new lesions in sound enamel adjacent to the infiltrated area.