Cavity preparation by Er-YAG laser on pulpal temperature rise.

PURPOSE: To measure the intrapulpal temperature changes in vitro, during cavity preparation and caries removal, using the Opus 20 Er-YAG laser plotted as a function of the laser energy and pulse rate.

MATERIALS AND

METHODS

Class I and V cavity preparations were made in 175 fresh extracted caries-free human teeth and caries removal was carried out in 42 carious extracted teeth by the Opus 20 Er-YAG laser. K-type thermocouples were inserted into the pulp chambers filled with heat conducting paste. Lasing was carried out at different irradiation energies and pulse frequencies, using air-water spray. Temperature changes in the pulp chamber were measured during lasing.

RESULTS

In all groups tested, the maximum temperature rise was lower than 5.5 degrees C, which is considered as critical value for pulp vitality. The highest temperature values were measured during Cl I preparations (3.13 degrees C +/- 1.54 - 4.11 degrees C +/- 1.29), medium values were in Cl V in enamel (2.38 degrees C +/- 1.37 - 4 degrees C +/- 1.07) and the lowest were in cementum (2.10 degrees C +/- 0.61 - 3.61 degrees C +/- 1.15) and during caries removal (1.21 degrees C +/- 0.46 - 3.51 degrees C +/- 0.68).