Influence of post type on degree of conversion of a resin-based luting agent

Purpose: To assess the degree of conversion (DC) at different levels of a resin-based luting agent used with different commercial posts. Methods: A resin-based luting agent (Variolink II) was light-cured in a simulated dowel space in combination with different fiber posts: GC Fiber Post (GC), DT Light Safety Lock (SL), RelyX Fiber Post (RX), Reforpost (RE), DT Light Post Illusion (LPI), FRC Postec Plus (FP), Radix (RA), Snowpost (SP), Dentin Post X (DP), Macro lock Illusion (MI), and Composipost (CP). After 24 hours, DC was assessed through micro-Raman analysis at the coronal, middle, and apical thirds. Two-way ANOVA and Tukey test were used for post-hoc comparisons (P< 0.05). Results: The results demonstrated that the post-type, dowel space level, and between-factor interaction were statistically significant (P< 0.001). Differences in DC were observed at different depths for RX, RE, LPI, SL, DP, MI and CP, decreasing from the coronal to the apical third. Although the resin-based luting agent should be able to polymerize in absence of light, a higher DC was found following light irradiation (with a decreasing effect from the coronal to the apical third). (Am J Dent 2012;25:17-20).