A survey on light intensity outputs of QTH, cabled and cordless LED light curing units

ABSTRACT

Light intensity output is one of the determinants for adequate curing of visible light-cured materials. The aim of this survey was to evaluate the light intensity outputs (LIOs) of light curing units (LCUs) in dental clinics of Hospital Universiti Sains Malaysia (HUSM) and School of Dental Sciences, Universiti Sains Malaysia (USM). The respective LIOs of all functioning Quartz Tungsten Halogen (QTH) and Light Emitting Diode (LED) LCUs were tested using two light radiometers. For cordless LED LCUs, the testing procedure was done in situ and after being fully charged. Statistical analysis using Kruskal Wallis and Wilcoxon signed ranks tests were performed to compare the LIOs between groups and between the LIOs of in situ and post-charged cordless LED LCUs, respectively. The level of significance was set at 0.05 (p<0.05). The results revealed that 72.72%, 42.47% and 92% of QTH, cabled LED and cordless LED LCUs exhibited acceptable LIOs, respectively. Data analysis using Kruskal Wallis test showed a statistically significant difference between groups (p<0.05). The intergroup comparisons using multiple Mann Whitney test with Bonferroni correction revealed a significant difference between the LIOs of cordless LED and both QTH and cabled LED (p<0.017). The difference between the LIOs of in situ and post charged cordless LED LCUs was also significant (p<0.05). In conclusion, both QTH and cordless LED LCUs performed better in term of LIOs than cabled LED LCUs. Periodic testing of LCUs is essential to ensure optimal performance.