Objectives: The purpose of this investigation was to evaluate the cure of an opaque shade of a contemporary resin composite when polymerised with a newer version of an LED light used at half the curing times of the original light. The degree of monomer conversion was evaluated. A halogen light served as control. Methods: Shade B0.5 of Z250 composite resin, was dispensed into a black nylotron cylindrical mould, 4mm diameter and 2mm deep. The specimens were irradiated for 10s, 20s, 30s and 40s with the XL3000 halogen light and the original LED light, Freelight whilst the corresponding specimens for the newer LED light, Freelight 2 were irradiated for half these times: 5s, 10s, 15s and 20s respectively. Diffuse reflectance FT-IR for degree of conversion tests was then carried out on them following dry specimen storage for 2days post-cure. Statistical significance was determined using two-way ANOVA and Tukey’s tests for multiple comparisons at a 0.05 confidence level. Results: The degree of conversion for the 10s-, 20s-, 30s- and 40s-halogen light activated specimens were 55.44%+0.92, 60.01%+3.94, 63.62%+3.15 and 62.82%+3.30 respectively and 49.91%+2.19, 56.60%+0.89, 57.42%+3.40 and 56.89%+4.78 respectively for the original LED light. The degree of conversion for the newer LED light-activated specimens were 48.31%+4.44, 50.77%+2.46, 52.35%+3.40 and 59.37%+2.44 for the 5s-, 10s-, 15s- and 20s-cure respectively. Conclusion: For each cure time period, there were no significant differences between the degree of conversion of specimens cured with the original LED light and specimens cured with the newer LED light at half the cure times tested. Neither were there any differences between the specimens cured for similar times (10s and 20s) with the two LED lights. The degree of conversion of specimens cured with the LED lights were however significantly lower than the halogen light activated specimens.