Temperaturveränderungen im Pulpakavum eines Zahnes während der Einwirkung von LED-Polymerisationslampen

LED curing lights are increasingly being used in all areas of adhesive treatment techniques. The aim of this study was to estimate the heating of a tooth and its potential damage when using a commercial LED curing light. Ten extracted human multi-root teeth were split along their longitudinal axis to expose two canals of the tooth roots. In the apical area of the canals, plastic cannulas were attached, which allowed the connection to a tube system for a circulation of fluid through the pulp chamber. The divided surface of the tooth was closed with a borosilicate cover glass. Each tooth was irradiated on its outer surface for 40 s with four different curing lights: (I) Bluephase Style (Ivoclar Vivadent, Ellwangen), (II) Elipar LED (Espe, Landsberg), (III) SmartLite Focus (Dentsply, Konstanz), (IV) Celalu2 (Voco, Cuxhaven). Temperature measurements were performed at fluid low rates of 0 ml, 2.6 ml and 6 ml/min in the areas of the pulp chamber, dentin and enamel-dentin-line using a thermographic camera (VarioCAM HD, InfraTec, Dresden). The used curing light models and the fluid circulation within the pulp chamber had a significant influence on the temperature rise. At a test-related initial temperature of 22 °C, the highest temperature increase for the curing light (I) was found without fluid circulation (median: 7.4 K, max: 9.4 K, min: 6.0 K). The lowest temperature increase within the pulp chamber could be measured after irradiation with curing lights (III) and (IV) at a liquid flow rate of 6 ml/min (III: median: 0.3 K, IV: median: 0.24 K) (p < 0.05). Assuming a physiological blood circulation rate, pulp tissue damage might not be expected for a curing time interval of 40 s with the LED curing devices under study.