Background: Temperature rise in the pulp chamber is a severe stress that can cause irreversible damage to the pulp. The objective of this study was to compare the temperature rise under primary teeth dentin induced by Light Emitting Diode (LED) with different light curing modes. Methods: sixty dentin discs of 0.5- 1- 1.5- and 2-mm thickness were prepared from human primary molars. Resin composite placed in an Teflon cavity was cured using a high-powered LED (Foshan JERRY Medical Apparatus CO., LTD, Foshan, China) for 20s. The different modes tested in this study were standard mode, ramp mode, and pulse mode (n=5). Temperature was recorded using a k-type thermocouple in direct contact with the dentin disc. Temperature change data were subjected to analysis of variance (ANOVA) and Tukey's test. Results: The highest temperature rise was observed under 0.5 mm thick dentin disc with standard mode (4.7 ± 0.42), whereas the lowest values were recorded with pulse mode under 2 mm thick dentin (2.5 ± 0.23). Pulse mode produced significant lower temperature rise compared to standard mode in all dentin thicknesses (P < 0.05). Ramp mode gave significantly lower values compared to standard mode in 0.5 mm group (P < 0.05). For standard and ramp modes, 0.5 mm thick group exhibit higher temperature rise than 2 mm thick group (P < 0.05). Conclusions: Maximum temperature rise induced by high-powered LED was not critical for pulpal health. Temperature rise related to dentin thickness and curing modes. Pulse mode gave the lowest values.

Aim This study was performed in order to determine the temperature rise under human dentin discs of different thicknesses of primary and permanent teeth during the photo-curing process with conventional halogen lamp and LED. Materials and methods The current experimental study sample consisted of 160 dentin discs of different thicknesses (0.5, 1, 1.5 and 2 mm) of which 80 dentin discs were prepared from healthy lower second primary molars and the remaining 80 dentin discs were prepared from healthy lower third permanent molars extracted surgically for various reasons. A "K" type of thermal tentacle was placed in the center of an acrylic resin base followed by the placement of a dentin disc. Then, the thermal changes was measured during the photo-curing of the composite using a second generation of light-emitting diode (LED) and quartz-tungsten-halogen (QTH) light curing units.

Background: Temperature rise in the pulp chamber is a severe stress that can cause irreversible damage to the pulp. The objective of this study was to compare the temperature rise under primary tooth dentin induced by a light emitting diode (LED) with different light curing modes.Methods: Sixty dentin discs of 0.5- 1- 1.5- and 2-mm thicknesses were prepared from human primary molars. The resin composite placed in a Teflon cavity was cured using a high-powered LED (Foshan JERRY Medical Apparatus CO., LTD, Foshan, China) for 20 s. The different modes tested in this study were standard mode, ramp mode, and pulse mode (n=5). Temperature was recorded using a k-type thermocouple in direct contact with the dentin disc. Temperature change data were subjected to analysis of variance (ANOVA) and Tukey's test.Results: The highest temperature rise was observed under a 0.5 mm thick dentin disc with standard mode (4.7 ± 0.42), whereas the lowest values were recorded with pulse mode under 2 mm thick dentin (2.5 ± 0.23). Pulse mode produced a significantly lower temperature rise than standard mode for all dentin thicknesses (P < 0.05). Ramp mode gave significantly lower values than standard mode in the 0.5 mm group (P < 0.05). For the standard and ramp modes, the 0.5 mm thick group exhibited a higher temperature rise than the 2 mm thick group (P < 0.05).Conclusions: Temperature rise related to dentin thickness and curing modes. The standard mode led to a significantly higher temperature rise under thinner dentin than the other modes. Pulse mode gave the lowest values. Thus, it is recommended for use in deep cavities. Clinical Significance: The temperature rise during polymerization of the resin composite with the high-powered LED appeared to be below 5.5 ℃. Hence, it appears to be safe for use in pediatric dentistry.

Background. Temperature rise in the pulp chamber is a severe stress that can cause irreversible damage to the pulp. This study aimed to evaluate the effect of three curing modes of a high-powered LED and two remining dentin thicknesses on the temperature rise under primary teeth dentin. Methods. One dentin disc of 1 mm thickness was prepared from human primary molar. The dentin disc was exposed to curing light using a high-powered LED for 10 s to simulate bonding agent polymerization (stage 1 curing). Five specimens of resin composite were cured for 20 s. The different modes tested were standard, ramp, and pulse mode (n = 5). After that, the dentin disc was adapted to 0.5 mm thick, and the experiments were repeated. Temperature change data were subjected to analysis of variance (ANOVA) and Tukey's test. Results. The highest temperature rise was observed under the 0.5-mm-thick dentin disc with standard mode (7.6 ± 0.2; 4.7 ± 0.4), whereas the lowest values were recorded with pulse mode under 1-mm-thick dentin (2.7 ± 0.1; 2.5 ± 0.2) during stage 1 curing and resin composite polymerization, respectively. Pulse mode produced significantly lower values than standard mode in all conditions (P < 0.05). An inverse proportion was found between the mean temperature rise values and the dentin thickness. Conclusions. High-powered LEDs should not be used to cure bonding agents in deep cavities. The maximum temperature rise induced by a high-powered LED during resin composite polymerization was not critical for pulpal health. Temperature rise related to dentin thickness and curing modes.