Intrapulpal Rise in Temperature Due to Various Curing Units- In Vitro Study

Abstract

Introduction: Dental pulp is a highly vascularized tissue whose vitality is known to be impaired during tooth preparation and clinical restorative procedures but the rise in its temperature during the use of light curing units is often overlooked. The dental pulp is a low compliance system which does not respond well to increased temperature. Aim: The purpose of this study was to examine the temperature rise caused by different light curing units i.e., LED (Light Emitting Diode), QTH (Quartz Tungsten Halogen), PAC (Plasma Arc Curing) and to examine the influence of Remaining Dentin Thickness (RDT) i.e., 2mm, 1mm and 0.5 mm on the temperature increase in pulp. Materials and Methods: Dentin disks of different thicknesses i.e., 0.5mm, 1mm and 2mm were prepared. Composite resin was placed on the dentin disks which were cured using three different lights. The intrapulpal changes in temperature during the curing of the composite resin were determined with the help of a thermo couple. Ten readings were taken for each light curing unit at 2mm, 1mm and 0.5 mm RDT and the temperature rise in Degree Celsius was recorded. Results: The changes in the intrapulpal temperature due to LED, QTH and PAC with 0.5mm, 1mm and 2mm RDT dentin disks were determined as a difference between the initial and maximum temperature values. When the results were compared among PAC and LED, the intrapulpal rise in temperature was significantly higher with PAC. With respect to QTH and LED and QTH and PAC, QTH had highly significant values of temperature rise when compared to LED and PAC. Conclusion: It was observed from the study that remaining dentin thickness is inversely proportional to temperature rise. Also, the choice of curing unit is vital when polymerising light activated resin based restorations minimise any thermal damage to pulp.

Keywords

• curing light
• dentin thickness
• pulp
• thermal damage