Evaluation of curing light intensity in private dental offices (2005)

Background: Success rate in composite restorations is associated with the degree of polymerization and light intensity. Objectives: The aim of this study was to evaluate the light intensity of curing units in private offices in Qazvin 2003. Methods: In this analytical study the light intensity of 62 light curing units were investigated before and after cleaning their light emitting tips using a radiometer. The results were classified in 3 groups as follows: A: sufficient intensity> 300 mw/cm2, B: borderline intensity (200-299 mw/cm2), and C: insufficient intensity<200 mw/cm2. Data were analyzed using chi-square and Pearson correlation tests. Findings: Mean intensity of curing units was 350.96mw/cm2 which increased significantly to 371.6mw/cm2 (p=0.01). Before cleaning, 67.8% of curing tips were in group A, 14.5% in B and 17.7% in C. After cleaning, 72.6% were in sufficient intensity group, 11.3% in borderline intensity, and 14.1% in insufficient intensity. Removing curing tips' contamination caused a significant increase in light intensity (p=0.01). Conclusion: Periodic assessment of light intensity and quality control of light curing units are mandatory.