Safety parameters for pulp temperature during selective ablation of caries by KTP laser in vitro.

Objective: To define the optimal parameters of KTP laser irradiation during a selective caries removal.

Materials and methods: Twelve decayed human teeth, recently extracted were used. Their root canals were prepared for insertion of a thermocouple probe into the pulp chamber. The demineralized tissues were colored by Acid Red 52 before proceeding to different conditions of irradiation.

Results: Pulpal temperature increases (below 3 degrees C) were found under the following parameters with 15 sec of continuous lasing: 400 mWatts, 0.10-msec pulse width, PRR <50 Hz for efficient caries removal. A resting time average of 70 sec was necessary to allow pulp temperature to get back to its baseline.

Conclusion: KTP laser can be used safely and without any pulp over-heating under certain irradiation conditions.