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| Author(s): |
Patricia Moreira de Freitas
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Odontologia (FO/SDO) |
| Defense date: | 2005-07-29 |
| Examining board members: |
Carlos de Paula Eduardo;
Altair Antoninha Del Bel Cury;
Marcia Martins Marques;
Moacyr Domingos Novelli;
Monica Campos Serra
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| Advisor: | Carlos de Paula Eduardo |
| Abstract | |
The continuing development and improvement of the techniques and materials have introduced the laser technology in the different specialties of Dentistry. Even though there are still few studies on the use of the Er,Cr:YSGG Laser on caries prevention, one believes that the enamel irradiation with this wavelength can lead to a more acid resistant surface. The aim of the present study was to evaluate the effect of different parameters of the Er,Cr:YSGG Laser irradiation on the enamel mineral loss. Forty five enamel samples obtained from third molars (3 x 3 mm) were randomly divided in 5 groups (n=9): G1 Er,Cr:YSGG Laser 0.25 W, 20 Hz, 2.84 J/cm 2 , G2 Er,Cr:YSGG Laser 0.50 W, 20 Hz, 5.68 J/cm 2 , G3 Er,Cr:YSGG Laser 0.75 W, 20 Hz, 8.52 J/cm 2 , G4 Treatment with fluoride toothpaste (positive control), G5 No treatment (negative control). After the surface treatment, the samples were submitted to a 2-weeks pH-cycling, consisted of the daily immersion in demineralizing and remineralizing solutions for 6 h e 18 h, respectively. Afterഊthe acid challenge, the samples were sectioned and the Knoop microhardness test was performed (25 g, 30 sec) at different depth from the enamel surface (15 µm - 300 µm). ANOVA and Student Newman Keuls tests were performed (α =5%). The percentage of lesion inhibition for each group was: G1- 36.64 %, G2- 37.98 %. G3 63.83% e G4 50.47 %. Regarding the percentage of mineral loss volume, Groups G1 (1391.81±521.65) and G2 (1291.90±656.49) did not differ from each other, but both were higher than group G3 753.32±287.07). All the groups irradiated with the Er,Cr:YSGG were similar to the positive control group (G4). The findings of the present study suggest that the Er,Cr:YSGG laser at 8.52 J/cm 2 can be an alternative for the enhancement of enamel acid resistant and that lower energy densities seem to present a cariostatic potential comparable to the use of fluoride dentifrice. (AU) | |