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Novel matrix formulation for resin composite: Chemical and biomechanical characterization - Part 1
Julyana Dumas Santos Silva1, Letícia Nunes de Almeida1, Antônio Silva Machado2
1Department of Oral Rehabilitation and Prevention, Dental School, Federal University of Goiás, Av. Universitária, Campus Colemar Natal e Silva, Goiânia, GO 74605-220, Brazil.
Adding cholesteryl methacrylate (CM) to dental composite resins significantly reduced polymerization shrinkage force and increased Knoop microhardness. These improvements were achieved without negatively impacting other key material properties like sorption, solubility, or oxidation vulnerability.
Area of Science:
- Materials Science
- Biomaterials Engineering
- Polymer Chemistry
Background:
- Dental composite resins are widely used restorative materials.
- Polymerization shrinkage force (PSF) and Knoop microhardness (KHN) are critical properties influencing clinical performance.
- Investigating novel monomers like cholesteryl methacrylate (CM) is essential for improving dental material properties.
Purpose of the Study:
- To evaluate the effects of incorporating cholesteryl methacrylate (CM) into Bis-GMA/TEGDMA based composite resins.
- To assess the impact of CM on polymerization shrinkage force (PSF), Knoop microhardness (KHN), sorption and solubility (SS), vulnerability to spontaneous oxidation (VOE), porosity (BES), viscosity (V), and cross-link density (CLD).
Main Methods:
- Synthesized CM and prepared composite resin formulations with varying CM percentages (0-24%).
- Evaluated PSF using a universal testing machine and KHN with a 50g load for 30s.
- Assessed SS per ISO 4049:2009, VOE via electrochemical methods, porosity using electron microscopy (BES), viscosity through rheological analysis, and CLD from hardness changes after ethanol storage.
Main Results:
- CM6 and CM12 groups exhibited significantly lower PSF (0.34 N) compared to CM0 (0.91 N).
- KHN values were higher in CM6 (32.03) and CM12 (31.03) compared to CM0 (25.83).
- No significant differences were found in SS, VOE, or CLD, although CM12 showed increased porosity.
Conclusions:
- Cholesteryl methacrylate (CM) effectively reduces polymerization shrinkage force in dental composites.
- Incorporating CM enhances initial Knoop microhardness without compromising other critical properties like sorption, solubility, or oxidation resistance.
- Further research may explore optimizing CM concentrations to mitigate increased porosity observed at higher levels.
