Material PerformanceEffect of drinks on the surface properties of dental resin composites

The aim of this study was to evaluate the effect of different drinks on the surface properties of the commercial resin composite Charisma cured by a light emitting diode (LED). Hardness, adsorption of components on the surface and porosity were analyzed through nano-indentation, polarized laser-induced fluorescence (PLF) and adsorption/desorption nitrogen isotherm methods, respectively. Specimens with a degree of cure of 70%, immersed for 24 h and 168 h in a sports drink, yogurt, soft drink and wine, showed changes on the specimen surfaces through PLF. These changes suggested that a very thin layer of drink components was adsorbed on the specimens, which were detected through polarization laser-induced fluorescence. This showed the influence of each drink and the time factors on the behavior of all specimens tested. Average pore sizes were of the same magnitude and the hardness values remained the same after specimens were immersed in the drinks, except for specimens immersed in yogurt, which showed higher hardness values than the control group, and the porosity could not be measured due to the small pore size and the low sensitivity of the analysis method. However, the hardness value for enamel was 10 times higher than that for the resin specimens and dentin.