Temperature rise in pulp chamber by curing lamps

An irreversible damage of the pulp would be the consequence at the intrapulpal temperature increase of 5.5C resulting in an intrapulpal temperature of about 42.5C.

Objectives: The purpose of present study was to evaluate of temperature rise in pulp when high power density curing light was applied to the cavity

Methods:

1. Insertion of a temperature sensor

- The tip of the temperature sensor is positioned in the palatal hole paying attention to that the tip is in contact with dentin that is opposed to the buccal cavity. Furthermore, care must be taken not to insert the sensor with too much force to avoid bending of the sensor.

2. Preparation of tooth & grouping

Preparation of a cylindrical cavity on the buccal side of the premolar with a diamond bur; depths 1.75 mm, width 2 mm, apical-coronal extension 4 mm. The tooth was light cured using three curing lamps;

Astralis 10 (AST10, Ivoclar Vivadent, Schaan, Liechtenstein),

Experimental curing light 1(EXP1, Ivoclar Vivadent, Schaan, Liechtenstein), and

Experimental curing light 2(EXP2, Ivoclar Vivadent, Schaan, Liechtenstein), the power density of which was 1200, 2000 and 3000 mW/cm2 respectively. The root of the tooth was immersed in water at 34C.

In each light, the distance from light tip to tooth was set to 1mm, 4mm or 7mm. The lights were activated for 60 sec in EXP1 & 2 and 30s in AST10 at each distance. The sensor in the pulp was hooked to a computer via a data logger (Agilent)

The data were analyzed using Two- way ANOVA with Tuckey at 95% confidence levels

Results:

AST10 EXP1 EXP2

1mm 38.4(0.6)a,3 49.0(0.4)a,2 55.4(0.7)a,1

4mm 36.4(0.2)b,3 42.64(0.2)b,2 43.7(0.1)b,1

7mm 34.7(0.3)c,2 39.4(0.3)c,1 39.5(0.5)c,1

Conclusion:

High power density curing light, the power density of which was over 2000mW/cm2 increase the pulp temperature much higher than 42.5C.