Efficacy of curing lights in use in private dental offices

Abstract

The use of curing lights (CL) is a routine among the dentists (D). The objective of this study was to evaluate the intensity (1)and heat/ glare (H) output of CL at private dental offices in Passo Fundo, RS, Brazil and to examine the degree of polymerization of photocured composite resins (PCR) .The I and H output were related to CL conditions, such as: cooling system (CS), filter (F), CL tip (T) and light bulb reflector (B), plus some information from a questionnaire applied to the D and the tactile testo An investigator using I and H radiometers (Demetron Res. Corp.) evaluated 140 CL. It was found 19 different types of CL. Primelite (Dentsply) was the most popular one (22,1%). The mean age of the CL was 5,5 years and the most frequent unit's age was 10 years (12,1%). Other frequent findings were: the 6 mm T size (63,5%), the daily use (73,5%) with a 40 s fixed exposure time (53,3%) and problems in the CS (63,6%), in the F (81,4%) and in the T (68,6%). Even though, most of the D (75%) were satisfacted with the performance of their CL. It was not found any problems with the units' B in 62,1%. The I readings ranged from O to 650mW/ em? and the mean was 215 ± 152 mW/cm2. The highest mean I readings were found with Optilux (Demetron) and XL1500 (3M) units. According the Demetron rating scale, 84 (60%) CL were considered inadequated even with increased time, 27 (19,3%) needed additional time and 29 (20,7%) were adequate to use. The H readings ranged from O to 300mW/cm2 and 55% ofthese readings were less than 50mW/cm2. The Vickers Hardness (VH) means were 46.3 ± 21 HV5 for VHR and 45.4 ± 21 HV5 for VHC. Positive correlation was found between the I readings and the VHR and VHC mean values. Negative correlation was found between the I readings and problems in the CS, F and T. The tactile test is not a sensitive means of measuring H. Key words: curing lights, composite resins, cerarmcs.