HPLC analysis of HEMA released from dual cured resin cements

Objectives: Components released from dental resins are essential factors in the assessment of biocompatibility of these materials. The aim of this study was to evaluate in vitro elution of 2-Hydroxyethyl methacrylate (HEMA) from dual polymerized resin cements, used for bonding of ceramic restoration by high perfomance liquid chromatography (HPLC). Methods: Twenty freshly extracted caries and restoration free molar teeth used in this study. Standardized Class I preparations were prepared in all teeth. A lithium disilicate based (IPS Empress Esthetic; Ivoclar) ceramic inlays were cemented with one of the dual cured resin cements (Rely X ARC; 3M ESPE or Nexus 2; Kerr).After cementation, specimens were stored in 75% ethanol solution. HPLC was used to analyze the amount of HEMA in the solution (after 10 min, 1 hour, 24 hours, 3, 7, 14 and 21 days). Two-way ANOVA and Tukey HSD tests were used to evaluate the results (p<.05). Results: There were statistically significant differences between resin cements according to the amount of released HEMA (p<.01) and also among time periods (p<.01). The amount of HEMA eluted from Nexus 2 was significantly higher than Rely X ARC. The total amount of monomers was the highest after 21 days (p<.01). Conclusions: In the case of resin cements, Nexus 2 showed the highest amount of HEMA. The amount of HEMA eluted from resin cements was influenced by the time.