CO2-lased enamel microhardness after brushing and cariogenic challenge

Author(s)

Correa-Afonso, Alessandra Marques ^[1] ; Bachmann, Luciano ^[2] ; de Almeida, Cintia Guimaraes ^[1] ; Palma Dibb, Regina Guenka ^[3] ; Milori Corona, Silmara Aparecida ^[3] ; Borsatto, Maria Cristina ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Odontol Ribeirao Preto, Dept Clin Infantil, BR-14040904 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Fis, BR-14040901 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Fac Odontol Ribeirao Preto, Dept Odontol Restauradora, BR-14040904 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Journal of Biomedical Optics; v. 18, n. 10 OCT 2013.
• Web of Science Citations: 1

Abstract

This study aimed to assess how the wear that brushing promotes affects CO2 laser-irradiated enamel microhardness after cariogenic challenge in vitro. Forty fragments measuring 4 x 4 mm were randomly assigned to four groups according to the enamel surface treatment: G1-control, G2-CO2-laser irradiation, G3-brushing, and G4-CO2 laser irradiation + brushing. A laser device emitting at 10.6 mu m was used (power 0.5 W, energy per pulse 0.05 mJ, and frequency 10 kHz). Specimens belonging to groups G3 and G4 were brushed (80,000 strokes) with a brushing simulator using toothpaste. Next, the samples were challenged with acid: the specimens were immersed in demineralizing and remineralizing solutions for 8 days. The acid resistance of enamel was evaluated by cross-sectional microhardness tests. The area under the curve (KHN x mu m) was calculated. Analysis of variance (ANOVA) one-away and Fisher's test were performed for the statistical analysis (p < 0.05). Group G2 specimens (31; 185 +/- 4706) were statistically different from specimens belonging to groups G1 (26; 723 +/- 2446), G3 (28; 194 +/- 1376), and G4 (28; 207 +/- 2234), which were statistically similar. The brushing time used in the present study probably wore the CO2-lased enamel, so demineralization could not be prevented in the brushed group. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE) (AU)

• FAPESP's process: 12/02460-6 - Vibrational spectroscopy applied to biological tissues: cancer diagnosis and chemical characterization of laser irradiated dental tissues
• Grantee: Luciano Bachmann
• Support type: Regular Research Grants
• FAPESP's process: 10/06861-0 - Influence of Nd:YAG and CO2 laser irradiation on chemical and ultra structural composition of dental enamel
• Grantee: Alessandra Marques Corrêa Afonso
• Support type: Scholarships in Brazil - Post-Doctorate