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°C, which is considered as critical value for pulp vitality. The highest temperature values were measured during Cl I preparations (3.13°C ± 1.54 - 4.11°C ± 1.29), medium values were in Cl V in enamel (2.38°C ± 1.37 - 4°C ± 1.07) and the lowest were in cementum (2.10°C ± 0.61 - 3.61°C ± 1.15) and during caries removal (1.21°C ± 0.46 - 3.51°C±0.68).