Temperature rise beneath a light–cured materials using two types of curing machines

Abstract

Aim: To measure the temperature rise induced by a light emitting diode (LED) curing unit and by quartz tungsten halogen (QTH) curing unit using two types of composite resin XRV Herculite and Venus. Materials and Methods: Forty extracted non–carious single canal premolars were cleaned and bisected longitudinally. Class V preparations were cut on the buccal surfaces. The teeth were divided into four groups; each of ten. The teeth in the first and second groups were restored with XR–Herculite composite resin. The teeth in the third and fourth groups were restored with Venus composite resin. The composite resin in the first and third groups were polymerized using QTH curing unit “Astralis” for 40 seconds; the light intensity was 502 mW/cm2. The distance between the tip of the light and the composite was 3 + 1 mm. The composite resin in the second and fourth groups was polymerized using LEDs “Ultra–Lite 200 E plus” curing unit for 20 seconds; the light intensity was 536 mW/cm2 using the same distance as the first and third groups. The temperature rise at the pulpal wall was recorded by placing a thermocouple on the pulpal wall directly under the restoration. Results: The lowest temperature rise during LED irradiation with Venus composite resin followed by LED irradiation with XRV Herculite composite resin. Whereas QTH curing units with XRV Herculite composite resin produced higher values, QTH curing units with Venus composite resin produced the highest temperature rise. Conclusion: The temperature rise of LED curing units and QTH curing units used in this study was under the limits that affect the integrity of the dental pulp.