Influence of Er,Cr:YSGG laser irradiation on enamel caries prevention

Author(s)

Geraldo-Martins, Vinicius Rangel ^{[1, 2]} ; Lepri, Cesar Penazzo ^[1] ; Palma-Dibb, Regina Guenka ^[1]

Affiliation

^[1] Univ Sao Paulo, Ribeirao Preto Sch Dent, BR-14040904 Ribeirao Preto, SP - Brazil

^[2] Univ Uberaba, BR-38055500 Uberaba, MG - Brazil

• Document type: Journal article
• Source: Lasers in Medical Science; v. 28, n. 1, p. 33-39, JAN 2013.
• Web of Science Citations: 18

Abstract

The objective of this study was to evaluate the effects of chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on the acid resistance of dental enamel. Forty human enamel samples were divided into four groups. They were manually irradiated with an Er,Cr:YSGG laser device (lambda = 2.78 A mu m, 20 Hz, 20 s), in a scanning mode, with and without water cooling, according to the following parameters: Group 1: 0.25 W, 62.5 J/cm(2), no water cooling; group 2: 0.25 W, 62.5 J/cm(2), 5.0 ml/min; group 3: 0.5 W, 125 J/cm(2), no water cooling; group 4: 0.5 W, 125 J/cm(2), 5.0 ml/min. No airflow was used. Afterwards, the samples were submitted to an acid challenge and assessed by cross-sectional Knoop microhardness at different depths (20, 40, 60, 80, and 100 A mu m) from the outer enamel surface. Average values were obtained for both irradiated and control areas in each sample and they were compared to obtain a percentage of microhardness increase. Data were analyzed by analysis of variance and Fisher's exact test (alpha = 5%). The percentage of microhardness increase observed in group 1 (+23.58%) was similar to group 3 (+19.12%), but higher than groups 2 (+3.61%) and 4 (10.9%) (p < 0.05). The comparison of the depths showed that the Er,Cr:YSGG laser acted in the superficial layers of the dental enamel. The findings of the present study suggest that the energy densities of 62.5 and 125 J/cm(2) were capable of increasing the acid resistance of human enamel. The presence of water during irradiation makes it difficult to obtain an enamel surface more resistant to acids. (AU)

• FAPESP's process: 08/07403-5 - Influence of different root caries removal methods on the dentin substrate and on glass ionomer restorations
• Grantee: Regina Guenka Palma-Dibb
• Support Opportunities: Regular Research Grants
• FAPESP's process: 07/08140-5 - INFLUENCE OF DIFFERENT METHODS OF ROOT CARIES REMOVAL ON DENTAL SUBSTRATE AND ON SEALING ABILITY OF GLASS IONOMER RESTORATIONS
• Grantee: Vinícius Rangel Geraldo Martins
• Support Opportunities: Scholarships in Brazil - Post-Doctoral