The effect of different pulp capping methods on the intrapulpal temperature when using light-cured procedures

BACKGROUND: To evaluate the intra-pulpal temperature during different direct pulp capping methods and light-cured procedures. MATERIAL AND METHODS: Class I preparations 5 mm long, 4 mm wide and 4 mm deep were performed in extracted third molars, leaving 0.5 mm of dentin at the pulpal floor with a 1 mm diameter of pulp exposure. Teeth were placed in a customized oral cavity chamber simulator in which the initial temperature was standardized at 36oC. The overall temperature variations (oC) in the pulp chamber during the light-activation processes were recorded live using an infrared camera (FLIR ONE PRO, FLIR Systems). The liners and bases evaluated were: Dycal (Dentisply), TheraCal LC (Bisco), Biodentin (Septodent), Vitrebond Plus (3M/ESPE), and Fuji IX GP (GC), followed by restoration with a bulk fill composite (EvoCeram Bulk Fill, Ivoclar Vivadent). All light-activation procedures were performed with the VALO Grand (Ultradent) light-curing unit. A power analysis was conducted to determine the sample size to provide a power of at least 0.8 with α=0.05. Statistical analyses were performed using ANOVA and Tukey’s test for multiple comparisons. RESULTS: The intrapulpal temperature increased above a 10oC to 20oC threshold difference for all liners and bases that were light cured. When added as second layers, neither of those could provide thermal insulation following additional light-activated procedures (p=0.25). The higher the number of procedures requiring light-activation, the longer the pulp temperature remained in those increased temperature thresholds. CONCLUSIONS: For direct pulp capping procedures, a reduced number light activation procedures should be indicated to reduce the time intra-pulpal temperature rises above a 10oC threshold. Key words:Liner, base, calcium hydroxide, glass ionomer, dental adhesive, bulkfill composite.