The effect of combining photoinitiator systems on the color and curing profile of resin-based composites

Autor(es)

Ramos Salles de Oliveira, Dayane Carvalho ; Rocha, Mateus Garcia ; Correa, No Carlos ; Correr, Americo Bortolazzo ; Ferracane, Jack L. ; Coelho Sinhoreti, Mario Alexandre

• Tipo de documento: Artigo Científico
• Fonte: Dental Materials; v. 32, n. 10, p. 1209-1217, OCT 2016.
• Citações Web of Science: 7

Resumo

Objective. To evaluate the effect of combining camphorquinone (CQ) and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) on the color and curing profile of resin-based composites. Methods. Experimental composites were produced with different CQ and TPO molar concentrations: CQ-only, 3CQ:1TPO, 1CQ:1TPO, 1CQ:3TPO, and TPO-only. Polywave LED was characterized using a beam profiler. Block-shaped samples (5 mm x 5 mm x 3 mm depth) were cured in a custom-designed mold with a polywave LED positioned to compare the regions exposed to the 420-495 nm and 380-420 nm LED emittances. To map the cure profile, degree of conversion (DC) of longitudinal cross-sections from each block were evaluated by FT-NIR. Color, light-transmittance and light-absorption during curing were evaluated on specimens 1-3 mm thick. Data were analyzed using ANOVA/Tukey's test (alpha = 0.05; beta = 0.2). Results. Though the polywave LED beam profile was non-uniform, up to a depth of 2 mm no differences in DC were found among the composites containing CQ with TPO added up to 50%, regardless of the position under the curing tip. Composites with higher TPO concentration showed a decrease in DC beginning with a depth of 1 mm, while composites with higher or similar CQ concentrations did not show decreased DC until a depth of 3 mm. Higher TPO concentration reduced initial yellowness and color change after curing; and lower CQ concentration decreased light-absorption at greater depths. Significance. The combination of CQ with TPO added up to 50% reduced the yellowness and color change of composites after curing without affecting cure efficiency up to a depth of 2 mm. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 16/06019-3 - Propriedades físico-químicas e resistência ao desgaste de compósitos odontológicos bulkfill comerciais e experimentais à base de monômero elastomérico
• Beneficiário: Mateus Garcia Rocha
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/04241-2 - Influência do sistema fotoiniciador e agentes redutores nas propriedades físicas de resinas experimentais fotoativadas por LEDs
• Beneficiário: Dayane Carvalho Ramos Salles de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Doutorado