Effect of Light Intensity on the Degree of Conversion of Dual-cured Resin Cement at Different Depths with the use of Translucent Fiber Posts

Objectives: To evaluate the effect of different light intensities on the degree of conversio (DC) of dual-cured resin cement at different depths of translucent fiber posts. Materials and Methods: Thirty translucent fiber posts were randomly assigned into thre (n=10) groups. They were cemented in the simulated canal spaces using Duo-Link dual cured resin cement. The cement was light-cured under 600, 800 and 1100 mW/cm2 ligh intensities for 40 seconds. DC of the resin cement was calculated at cervical, middle an apical thirds using the spectra of FT-Raman spectrometer. Data were analyzed by repeate measurement ANOVA and Tukey’s post hoc tests (α=0.05). Results: In all the groups, the least DC was obtained at the apical region. There were n significant differences in the DC with different light intensities between the cervical an middle regions (p>0.05). However, in the apical region, the DC in both 800 and 110 mw/cm2 was similar (p>0.05), but greater with 600 mW/cm2 light intensity (p=0.02 an p<0.001, respectively). Conclusion: In comparison with the light intensity of 600 mW/cm2, the light intensity o 800 mW/cm2 significantly increased the DC of dual-cured resin cement in the apical region However, DC was not significantly different between 800 and 1100 mw/cm2 light intensi ties. If the resin cement, especially in the apical areas is not sufficiently cured, microlea kage might increase and post retention might be jeopardized. In comparison with 60 mW/cm2 light intensity, 800 mW/cm2 significantly increases DC at the apical third tha might be clinically beneficial.