Influence of Photoactivation Source on Restorative Materials and Enamel Demineralization

Autor(es)

de Sena Popoff, Josiane Marques ^[1] ; Rodrigues, Jose Augusto ^[1] ; De Freitas Aras, Wanessa Maria ^[2] ; Cassoni, Alessandra ^[1]

Afiliação do(s) autor(es)

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

^[2] Southwest State Bahia Univ, Sch Dent, Dept Restorat Dent, Itapetinga, BA - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Photomedicine and Laser Surgery; v. 32, n. 5, p. 274-280, MAY 2014.
• Citações Web of Science: 0

Resumo

Objective: The objective of this study was to evaluate the influence of the photoactivation source on the polymerization depth of restorative materials and its effects on resistance to enamel demineralization. Background data: Argon-ion laser (AL) irradiation itself provides a reduced depth of caries lesions in sound enamel. Methods: Eighteen human teeth were sectioned into 36 blocks and distributed into two groups according to the respective restorative material: resin-modified glass ionomer material (RMGI) (Vitremer-3M ESPE; A3; n = 18) and composite resin (CR) (Z350-3M ESPE; n = 18). Each group was subdivided into three subgroups and activated by a quartz-tungsten-halogen (QTH) lamp, an AL, or a light-emitting diode (LED) (n = 6). Knoop microhardness (KHN) analysis of the materials was evaluated at two different depths: 0 and 1.6 mm from the enamel surface. The blocks were thermocycled and submitted to five demineralization-remineralization cycles at 37 degrees C. The KHN values of the enamel surface (0 mm) were evaluated. The specimens were longitudinally sectioned, and the restorative material was evaluated at a depth of 1.6 mm. Data were evaluated by two way analysis of variance (ANOVA) and Tukey tests (p < 0.05). The evaluation of subsuperficial enamel demineralization by KHN analysis was conducted by seven indentations located at 100 mu m from the restored cavity. Data were evaluated by three way ANOVA and Tukey tests (p < 0.05). Results: Comparing the two restorative materials, the KHN values at the surface (0 mm) were greater for CR, whereas at 1.6 mm, they were greater for RMGI. In addition, there was less development of enamel demineralization around RMGI restorations than CR restorations. Moreover, there were statistically significant differences on subsuperficial enamel demineralization between the two restorative materials and between the three photoactivation methods (p < 0.05); RMGI presented the highest KHN values, and QTH and AL presented the lowest. Conclusions: The photoactivation source did not influence superficial enamel demineralization, but LED activation positively influenced the subsuperficial microhardness of enamel. (AU)

• Processo FAPESP: 09/02240-3 - Análise visual e quantitativa do potencial cariostático e microdureza de restaurações de resina composta e cimento de ionômero de vidro resino-modificado fotoativados com laser de íon argônio comparadas com luz halógena e LED
• Beneficiário: Alessandra Cassoni Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular