Polymerization kinetics of resin cements after light activation through fibre posts: an in vitro study. (28th June 2014) - Khabeer, A.
Abstract Aim To measure the polymerization of light‐cured (Variolink Veneer, VLV) and dual‐cured (Variolink II, VLII) resin luting cements after light activation through different lengths of fibre post ex vivo. Methodology Degree of conversion after prolonged direct light activation (PLA) [12 min after LED light activation for 3 min] was determined using ATR‐FTIR. Models were then produced to allow samples of VLV and VLII (n = 5 each group) to be light‐activated through 3, 6 and 9 mm lengths of fibre post (Fiber Lux). Degree of conversion was assessed by ATR‐FTIR and expressed as a percentage of the degree of conversion achieved after PLA. Data were analysed using anova and Tukey's test (P < 0.05). Results Mean [SD] degree of conversion for VLV and VLII after PLA was 57.97% [1.51] and 54.71% [3.77], respectively. Light activation of VLV through a 3 mm post produced 81.62% of the PLA value, compared with 71.03% for the 6 mm and 46.04% for the 9 mm post. Conversion after activation through 9 mm posts was significantly less than through 3 mm and 6 mm posts (P < 0.05). For VLII, activation through a 3 mm post produced 66.51% of the PLA value, compared with 54.38% for the 6 mm and 41.56% for the 9 mm post. A significant decrease in degree of conversion was noted for VLII as post length increased (P < 0.05). Conclusions The degree of conversion for VLV reduced after light activation through 9 mm posts when compared to 3 mm and 6 mm posts, whilst the degree of conversion for VLII decreased with every increase in post length.