engleski

The temperature changes in the pulp chamber during the cavity preparation with Er:YAG laser using a very short pulse

Objective: The aim of this study was to examine the temperature changes in the pulp chamber during cavity preparation with Er:YAG laser ( =2940 nm) with a very short pulse (VSP). Materials and methods: Nine groups of 10 intact molars were used. One root of each sample was amputated and thermocouple of thermometer (Fluke 52, Fotronic, USA) was inserted in the chamber. Class V cavity preparation in enamel was prepared, and then the preparation was proceed in dentine. Enamel was lased with 400 mJ, 360 mJ and 320 mJ in contact mode using the very short pulse with duration of 100  s. Diameter of fiber tip was 950  m. Frequencies of 15 Hz, 12 Hz and 10 Hz were used, and total time of irradiation was 10 s. Dentine was irradiated with 340 mJ, 280 mJ and 200 mJ and 10 Hz, 8 Hz and 5 Hz during 7 s. Cooling was done with water spray (73 psi / 50 mL/min). The differences were tested by MANOVA and Bonforroni post hoc test. Results: The highest rise in temperature in the pulp was achieved after enamel irradiation by 400 mJ/15 Hz (1.99  0.28 C), and the lowest for the enamel after irradiation by 320 mJ/10 Hz (0.70  0.18 C). In dentine the highest temperature increase was achieved with 340 mJ/10 Hz (1.37  0.42 C), and the lowest with 200 mJ/5 Hz (0.43  0.18 C). Two-way interaction for enamel and dentine showed that influence of energy on temperature increase is stronger than the influence of frequency. Conclusion: Cavity preparation with Er:YAG laser using a VSP mode in vitro did not caused significant increase of temperature in the pulp chamber of human molars.

Er:YAG laser; cavity preparation; temperature changes; pulp chamber

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