Shrinkage Stress and Temperature Variation in Resin Composites Cured via Different Photoactivation Methods: Insights for Standardisation of the Photopolymerisation

Autor(es)

Sousa, Guilherme dos Santos ^[1] ; Guimaraes, Gabriel Felipe ^[2] ; Marcelino, Edilmar ^[1] ; Petit Rodokas, Jose Eduardo ^{[1, 3]} ; de Oliveira Junior, Arilson Jose ^[2] ; Cesarino, Ivana ^[2] ; Leao, Alcides Lopes ^[2] ; Riccardi, Carla dos Santos ^[2] ; Arjmand, Mohammad ^[4] ; Simoes, Rafael Plana ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Med Sch, Ave Prof Mario Rubens Guimaraes Montenegro S-N, BR-18618687 Botucatu, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Sch Agr, Dept Bioproc & Biotechnol, St Jose Barbosa de Barros 1780, BR-18610034 Botucatu, SP - Brazil

^[3] Sao Paulo State Univ UNESP, Sch Engn, Ave Eng Luiz Edmundo Carrijo Coube 14-01, BR-17033360 Bauru, SP - Brazil

^[4] Univ British Columbia UBC, Sch Engn, 3333 Univ Way, Kelowna, BC V1V 1V7 - Canada

• Tipo de documento: Artigo Científico
• Fonte: POLYMERS; v. 13, n. 13 JUL 2021.
• Citações Web of Science: 0

Resumo

The literature has shown that there is no consensus regarding the best resin composite photoactivation protocol. This study evaluated the efficiency of the conventional, soft-start, pulse-delay and exponential protocols for photoactivation of resin composites in reducing the shrinkage stress and temperature variation during the photopolymerisation. The photoactivation processes were performed using a photocuring unit and a smartphone app developed to control the irradiance according each photoactivation protocol. These photoactivation methods were evaluated applying photoactivation energies recommended by the resins manufactures. Three brands of resin composites were analysed: Z-250, Charisma and Ultrafill. The cure effectiveness was evaluated through depth of cure experiments. All results were statistically evaluated using one-way and multi-factor analysis of variance (ANOVA). The use of exponential and pulse-delay methods resulted in a significant reduction of the shrinkage stress for all evaluated resins; however, the pulse-delay method required too long a photoactivation time. The increases on the temperature were lower when the exponential photoactivation was applied; however, the temperature variation for all photoactivation protocols was not enough to cause damage in the restoration area. The evaluation of the depth of cure showed that all photoactivation protocols resulted in cured resins with equivalent hardness, indicating that the choice of an alternative photoactivation protocol did not harm the polymerisation. In this way, the results showed the exponential protocol as the best photoactivation technique for practical applications. (AU)

• Processo FAPESP: 21/05045-9 - Tensão de contração e variação de temperatura em resinas compostas curadas por diferentes métodos de fotoativação: Insights para padronização da fotopolimerização
• Beneficiário: Rafael Plana Simões
• Modalidade de apoio: Auxílio à Pesquisa - Publicações científicas - Artigo
• Processo FAPESP: 17/08188-0 - Estudo da variação de intensidade luminosa em processos de fotoativação de resinas compostas odontológicas e seus efeitos para minimização da contração de polimerização
• Beneficiário: Gabriel Felipe Guimaraes
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica