INFLUENCE OF CO2 LASER POWERS IN THE TEMPERATURE OF PRIMARY ENAMEL

Rodrigo Alexandre Valério, Caio Cesar Pereira Simon, Luciano Bachmann, Silmara Aparecida Milori Corona and *Maria Cristina Borsatto

ABSTRACT

Objectives: Different types of CO2 laser power are used to irradiate primary teeth, however, the study of these powers has fundamental importance, since, the use of correct parameters prevent the occurrence of thermal damage to the pulp tissue. The aim of the present in vitro study was to evaluate the temperature change on specimens of primary enamel irradiated with different powers of CO2 laser. Methods: Fifteen sound primary molars were sectioned mesiodistally, resulting in 30 specimens (3.5x3.5x2.0 mm). Two small holes were made on the dentin surface using round bur in high speed turbine (1/4), in which K-type thermocouples were installed to evaluate thermal changes. Specimens were individually fixed with wax in Plexiglass cylinders and randomly assigned in 3 groups (n=10) according to the powers used: (A) 0.5 W, (B) 1.0 W and (C) 1.5 W. The CO2 laser (λ=10.6 µm) was applied in an ultrapulse mode (non-contact), 4 mm focal length, 20 Hz frequency, and beam diameter of 0.4 mm. Temperature reading was performed every 0.3 seconds for 30 seconds. Analysis of variance (ANOVA) were performed for the statistical analysis (p≤0,05). Results: CO2 laser powers provided no difference on the temperature changes on specimens of primary enamel, in which the following means were observed: (A) 49.32°C ± 11.87, (B) 44.75°C ± 8.3 and (C) 47.48°C ± 6.88. Conclusions: It can be concluded that the CO2 laser was not influenced by different powers (0.5W, 1.0W, 1.5W), used in the irradiation of primary enamel teeth fragments.

Keywords: Lasers, temperature, dental enamel, primary teeth.