In vitro evaluation of erbium, chromium:yttrium-scandium-gallium-garnet laser-treated enamel demineralization

Author(s)

de Freitas, Patricia M. ^[1] ; Rapozo-Hilo, Marcia ^[2] ; Eduardo, Carlos de P. ^[1] ; Featherstone, John D. B. ^[2]

Affiliation

^[1] Univ Sao Paulo, Dept Restorat Dent, Sch Dent, BR-05508900 Sao Paulo - Brazil

^[2] Univ Calif San Francisco, Dept Prevent & Restorat Dent Sci, San Francisco, CA 94143 - USA

• Document type: Journal article
• Source: Lasers in Medical Science; v. 25, n. 2, p. 165-170, MAR 2010.
• Web of Science Citations: 26

Abstract

This study evaluated the effect of different parameters of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on enamel mineral loss in a simulated caries model. Forty-five enamel samples obtained from third molar teeth (3 mmx 3 mm) were randomly divided into five groups (n = 9): G1-Er,Cr:YSGG laser at 0.25 W, 20 Hz, 2.8 J/cm(2); G2-Er,Cr:YSGG laser at 0.50 W, 20 Hz, 5.7 J/cm(2); G3-Er,Cr:YSGG laser at 0.75 W, 20 Hz, 8.5 J/cm(2); G4-sodium fluoride (NaF) dentifrice (positive control); G5-no treatment (negative control). After irradiation, the samples were submitted to 2 weeks of pH cycling. After the acid challenge, the samples were assessed by cross-sectional microhardness at different depths from the enamel surface. Analysis of variance (ANOVA) and Student-Newman-Keuls tests were performed (alpha = 5%). The percentage of lesion inhibition for each group was: G1 37%; G2 38%; G3 64%, and G4 50.5%. Regarding the relative mineral loss values (micrometers x volume percent), groups G1 (1,392 +/- 522) and G2 (1,292 +/- 657) did not differ significantly from each other, but both had higher values than group G3 (753 +/- 287); the groups irradiated with Er,Cr:YSGG laser did not differ from group G4. Although the findings of the study revealed that Er,Cr:YSGG laser irradiation at 8.5 J/cm(2) can be an alternative for the enhancement of the enamel's resistance to acid, lower energy densities also produced a cariostatic potential comparable to the use of fluoride dentifrice. (AU)

• FAPESP's process: 98/14270-8 - Center for Optical and Photonics Science
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC