Evaluation of the effect of hybrid ceramics thickness and translucency on degree of conversion and microhardness of resin cements

Objective: The aim of this study was to determine the conversion degree and microhardness a light cured and a dual cured resin cement which are used in the cementation of full all ceramic restorations under different thicknesses of translucent and high transluscent Polimer ınflirated ceramic network (PICN) ceramic material. Method: Translucent (T) and high translucent (HT) PICN blocks were prepared 0.5, 1, 1.5, 2 mm thicknesses (n=80). Resin cement samples for FTIR analysis were prepared with a diameter of 6 mm and a thickness of 100 μm. Light cure resin cement was polymerized for 30 seconds and dual cure resin cement was polymerized for 20 seconds (n=180). Samples were stored in the dark for 24 hours at room temperature before FTIR spectrometer was used for degree of conversion measurements. For microhardness test, a teflon mold having 2 mm thicknes and 6 mm diameter was prepared. The polymerization protocol was the same as the samples prepared for FTIR analysis (n=180). Microhardness were measured using by a Vickers microhardness test device. The obtained data were analyzed statistically in a statistical software package. Results: As a result of FTIR analysis, conversion degree of the light cured resin cement that were prepared under 1.5 and 2 mm thick T and HT ceramics were found to be lower than the control group. It was observed that the conversion degree of the dual cure resin cement group there was no significant difference between the control group. When the microhardness values were examined, light cured resin cement ceramics were prepared under 1.5, 2 mm thick T and HT ceramics showed statistically significant low microhardness values. Dual cure resin cement were prepared under 1.5 and 2 mm thick T and HT ceramics showed statistically significant low microhardness values. Conclusion: ın the limitation of present study, it may be conculuted that, dual cured resin cements are more suitable in the cementation of restorations prepared at thicknesses of 1.5 mm and above both T and HT hybrid ceramics. Key words: Hybrid ceramic, resin cement, degree of conversion, microhardness