Effects of High-Energy Curing Lights on Time-Dependent Temperature Changes of Pulp Space During Orthodontic Bonding

Özet

Objective: The purpose of this study was to assess the temperature changes and cooling times during orthodontic bonding by alight-emitting diode (LED) and plasma arc lights (PAC) in different time and power modes with thermal imaging.Methods: A total of 100 human permanent upper first premolar teeth were included in the study. Five groups were conducted, 20teeth each, and different energy outputs of curing lights were used for adhesive polymerization with different exposure times. Thetemperature changes in the pulp space and cooldown times were measured by a thermal imaging system. A paired t-test, analysis ofvariance (ANOVA), and Student-Newman-Keuls multiple comparison tests were used for data analysis.Results: A statistically significant temperature rise was detected with all curing lights (p<0.05). The greatest temperature changeswere observed in the LED standard mode with 10 seconds of exposure time (6.66±1.98°C) and LED extra power mode with 6 secondsof exposure time (6.50±1.64°C) among groups, while using PAC for 3 seconds created the smallest temperature increase (1.81±0.99°C).An application of the LED extra power mode for 6 seconds exhibited the longest cooldown time (205.91±47.48 seconds), and theshortest cooldown time was detected as 71.30±43.15 seconds with the PAC 3-second application.Conclusions: LED lights with an increased exposure time induced significant temperature rises, while no PAC light group exceededthe critical threshold value. The exposure time is more important than the energy output level of the light-curing system on tempera-ture increments of the pulp chamber.