Spectrophotometric assessment of the effects of 10% carbamide peroxide on enamel translucency

tooth shade results from the interaction between enamel color, enamel translucency and dentine color. a change in any of these parameters will change a tooth？s color. the objective of this study was to evaluate the changes occurring in enamel translucency during a tooth whitening process. fourteen human tooth enamel fragments, with a mean thickness of 0.96 mm (± 0.3 mm), were subjected to a bleaching agent (10% carbamide peroxide) 8 hours per day for 28 days. the enamel fragment translucency was measured by a computer controlled spectrophotometer before and after the bleaching agent applications in accordance with ansi z80.3-1986 - american national standard for ophthalmics - nonprescription sunglasses and fashion eyewear-requirements. the measurements were statistically compared by the mann-whitney non-parametric test. a decrease was observed in the translucency of all specimens and, consequently, there was a decrease in transmittance values for all samples. it was observed that the bleaching procedure significantly changes the enamel translucency, making it more opaque.