Evaluation of flexural modulus, flexural strength and degree of conversion in BISGMA/TEGDMA resin filled with montmorillonite nanoparticles

Autor(es)

Campos, Luiza M. P. ; Boaro, Leticia C. ; Santos, Tamiris M. R. ; Marques, Pamela A. ; Almeida, Sonia R. Y. ; Braga, Roberto R. ; Parra, Duclerc F.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF COMPOSITE MATERIALS; v. 51, n. 7, p. 927-937, MAR 2017.
• Citações Web of Science: 5

Resumo

This study had as its main objective to evaluate the flexural properties (strength and modulus) and degree of conversion of a dimethacrylate resin containing different amounts of nanoparticulated clay Montomorillonite (MMT) as filler. A series of composites containing similar amounts (in volume) of barium glass particles was also tested as control data. Eight formulations with polymeric matrix-based BisGMA/TEGDMA (Bisphenol A Bis(2-hydroxy-3 methacryloxypropyl) Ether/Triethyleneglycol Dimethacrylate), four added with MMTand four added with barium glass in the volume concentration of 20, 30, 40 and 50 vol% were studied. The degree of conversion was determined using near-IR spectroscopy. Elastic modulus and flexural strength were determined by the three-point bending test. The dispersion of MMT nanoparticles was determined by means of X-ray diffraction and transmission electron microscopy analysis. The fillers montomorillonite and barium glass interacted with polymer matrix-based BisGMA/TEGDMA in a distinct manner. Although the addition of montomorillonite nanoparticles resulted in similar degree of conversion and higher elastic modulus values at all concentrations tested, only at the 20 vol% the flexural strength was statistically higher, compared to the control groups filled with barium glass. This could be related to the need of concentration optimization of montomorillonite for each type of polymer matrix in order to adjust or improve mechanical properties. The addition of low concentrations (< l 20% vol) of montomorillonite nanoparticles in dental composites resins -such as additive or hybrid filler -should be studied, aiming to the reduction of polymerization shrinkage, better mechanical properties and improvement of a new technology for future applications. (AU)

• Processo FAPESP: 13/07229-3 - Estudo da adição de nanopartículas argilominerais em matrizes poliméricas fotoativadas a base de bisgma/tegdma, aplicadas à odontologia.
• Beneficiário: Luiza Mello de Paiva Campos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado