Physical and Mechanical Properties of Resins Blends Containing a Monomethacrylate with Low-polymerization Shrinkage

Aurealice Rosa Maria Martins; Luciana Machado-Santos; Regis Cleo Fernandes Grassia Jr; Rafael Pino Vitti; Mário Alexandre Coelho Sinhoreti; William Cunha Brandt

doi:10.1055/s-0040-1716985

Physical and Mechanical Properties of Resins Blends Containing a Monomethacrylate with Low-polymerization Shrinkage

Eur J Dent. 2021 Feb;15(1):96-100. doi: 10.1055/s-0040-1716985. Epub 2021 Jan 7.

Authors

Aurealice Rosa Maria Martins¹, Luciana Machado-Santos², Regis Cleo Fernandes Grassia Jr³, Rafael Pino Vitti^{2

4}, Mário Alexandre Coelho Sinhoreti¹, William Cunha Brandt³

Affiliations

¹ Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
² Department of Prosthodontics, School of Dentistry, University of Taubaté, Taubaté, SP, Brazil.
³ School of Dentistry, Santo Amaro University, São Paulo, SP, Brazil.
⁴ School of Dentistry, Herminio Ometto University Center, Araras, SP, Brazil.

Abstract

Objectives: The aim of this study was to evaluate the Knoop hardness (KH), cross-link density (CLD), water sorption (WS), water solubility (WSB), and volumetric shrinkage (VS) of experimental resins blends containing a monomethacrylate with low-polymerization shrinkage.

Materials and methods: A blend of bisphenol glycidyl methacrylate (BisGMA) as base monomer was formulated with (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA), Bis-GMA/isobornyl methacrylate (IBOMA), or Bis-GMA/TEGDMA/IBOMA in different concentrations (40, 50, or 60 wt%). The camphorquinone (CQ)/2-(dimethylamino) ethyl methacrylate (DMAEMA) was used as the photoinitiator system. The KH and CLD were measured at the top surface using an indenter. For WS and WSB, the volume of the samples was calculated in mm³. The samples were transferred to desiccators until a constant mass was obtained (m1) and were subsequently immersed in distilled water until no alteration in mass was detected (m2). The samples were reconditioned to constant mass in desiccators (m3). WS and WSB were determined using the equations m2 - m3/V and m1 - m3/V, respectively. VS results were calculated with the density parameters before and after curing.

Statistical analysis: Data were submitted to ANOVA and Tukey's test (α = 0.05).

Results: The resins containing IBOMA showed lower VS results. TEGDMA 40% and TEGDMA/IBOMA 20/20 wt% showed higher KH values. The IBOMA groups showed lower CLD, while TEGDMA groups had higher values of CLD. The BisGMA/TEGDMA resin presented the highest values of WS, and for WSB, all groups showed no significant differences among themselves.

Conclusion: The monomethacrylate with low-polymerization shrinkage IBOMA used alone or in combination with TEGDMA may decrease VS, WS, and CLD values.

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