Effect of erbium:yttrium-aluminum-garnet laser energies on superficial and deep dentin microhardness

Author(s)

Chinelatti, Michelle Alexandra ^[1] ; Raucci-Neto, Walter ^[1] ; Milori Corona, Silmara Aparecida ^[1] ; Palma-Dibb, Regina Guenka ^[1]

Affiliation

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

• Document type: Journal article
• Source: Lasers in Medical Science; v. 25, n. 3, p. 317-324, MAY 2010.
• Web of Science Citations: 10

Abstract

This study evaluated the microhardness of superficial and deep dentin irradiated with different erbium:yttrium-aluminum-garnet (Er:YAG) laser energies. Seventy-two molars were bisected and randomly assigned to two groups (superficial dentin or deep dentin) and into six subgroups (160 mJ, 200 mJ, 260 mJ, 300 mJ, 360 mJ, and control). After irradiation, the cavities were longitudinally bisected. Microhardness was measured at six points (20 A mu m, 40 A mu m, 60 A mu m, 80 A mu m, 100 A mu m, and 200 A mu m) under the cavity floor. Data were submitted to analysis of variance (ANOVA) and Fisher's tests (alpha = 0.05). Superficial dentin presented higher microhardness than deep dentin; energy of 160 mJ resulted in the highest microhardness and 360 mJ the lowest one. Values at all points were different, exhibiting increasing microhardness throughout; superficial dentin microhardness was the highest at 20 A mu m with 160 mJ energy; for deep dentin, microhardness after irradiation at 160 mJ and 200 mJ was similar to that of the control. The lowest energy increased superficial dentin microhardness at the closest extent under the cavity; deep dentin microhardness was not altered by energies of 160 mJ and 200 mJ. (AU)

• FAPESP's process: 05/01680-9 - Influence of energy Er: YAG laser in ablation capacity, microhardness and dentine morphological in different depths
• Grantee: Regina Guenka Palma-Dibb
• Support Opportunities: Regular Research Grants