Effect of photo-polymerization mode on the degree of conversion of resin cement under different ceramic materials

Abstract

BacKGrOUND: this study evaluated the effect of different polymerization modes and duration on the degree of conversion (Dc) of resin cement under different types of ceramics. MetHODS: ceramic materials were divided into 3 groups (N.=60): group 1, cerasmart; group 2, Vita enamic; and group 3, Vita Mark ii. each group was then divided into three subgroups (N.=20) according to the polymerization mode (a: low-intensity; B: high-intensity; and c: soft-start). Subgroups were then divided into two further groups according to the polymerization time (i: 10 s; and ii: 20 s). Dc of light-cured resin cement beneath different kinds of ceramics was tested using Ftir spectroscopy. results were compared to a control group cured without overlying ceramic. RESULTS: While the type of ceramic and mode of polymerization showed a significant effect on the DC of resin cement, polymerization duration did not. Vita Mark ii group showed the highest Dc of resin cement followed by Vita enamic and Cerasmart. High- and low-intensity polymerization modes did not show significant difference, but both showed significantly lower Dc when compared to soft start mode. cONclUSiONS: type of ceramic and polymerization mode showed a direct effect on the Dc of resin cement.