Marina Lermenn Vidal1, Guilherme Ferreira Rego1, Gil Mendes Viana2, Lucio Mendes Cabral2, Juliana Primo Basílio Souza3, Nick Silikas4, Luis Felipe Schneider5, Larissa Maria Cavalcante6. 1. School of Dentistry, Federal Fluminense University - UFF, Niterói, RJ, Brazil. 2. School of Pharmacy, LabTIF, Federal University of Rio de Janeiro - UFRJ, Ilha do Fundão, Rio de Janeiro, RJ, Brazil. 3. Federal Center for Technological Education Celso Suckow da Fonseca - CEFET, Rio de Janeiro, RJ, Brazil. 4. Biomaterials Science Research Group, School of Dentistry, University of Manchester, Manchester, UK. 5. School of Dentistry, Federal Fluminense University - UFF, Niterói, RJ, Brazil; Nucleus for Dental Biomaterials Research, UVA-Veiga de Almeida University, Rio de Janeiro, RJ, Brazil. 6. School of Dentistry, Federal Fluminense University - UFF, Niterói, RJ, Brazil; Nucleus for Dental Biomaterials Research, UVA-Veiga de Almeida University, Rio de Janeiro, RJ, Brazil; School of Dentistry, UNIVERSO-Salgado de Oliveira University, Niterói, RJ, Brazil. Electronic address: lara_cavalcante@yahoo.com.br.
Abstract
OBJECTIVE: Investigate physical and chemical properties of model composites formulated with quaternary ammonium salt monomers (QAS) at different concentrations and alkyl chains lengths METHODS: QAS with 12 dimethylaminododecyl methacrylate (DMADDM) and 16 dimethylaminohexadecyl methacrylate (DMAHDM) chains lengths were synthesized and incorporated at 5 and 10% in model composites, resulting in four groups: G12.5 (DMADDM 5%), G12.10 (DMADDM 10%), G16.5 (DMAHDM 5%), G16.10 (DMAHDM 10%). One group was used as control group (CG 0%). Degree of conversion (DC); water sorption (WS) and solubility (SL); hygroscopic expansion (HE); degradation temperature (DT); glass transition temperature (Tg) and polymerization shrinkage (PS) were determined. Knoop hardness (KNH), flexural strength (FS) and elastic modulus (EM) were measured before and after storage Data were submitted to ANOVA and Tukey's test (p≤0.05). RESULTS: DC ranged between 76.1 (G12.10) and 70.7 (G16.5) %; CG had the lowest WS, SL and HE. There was no statistical difference for PS and FS. KHN values ranged between 30.2 (GC) and 25 (G16.10) and after storage the performance was depended on QAS concentration and chain length. For EM, CG had the highest values before and after storage and no difference was observed in the QAS groups before storage. After storage, the results were dependent on QAS concentration (3.5-4.3GPa). SIGNIFICANCE: In general, the addition of QAS increased composite's degradation compared with the CG. In the tested QAS, the addition of DMADDM at 5% concentration resulted in a less degradable material.
OBJECTIVE: Investigate physical and chemical properties of model composites formulated with quaternary ammonium salt monomers (QAS) at different concentrations and alkyl chains lengths METHODS: QAS with 12 dimethylaminododecyl methacrylate (DMADDM) and 16 dimethylaminohexadecyl methacrylate (DMAHDM) chains lengths were synthesized and incorporated at 5 and 10% in model composites, resulting in four groups: G12.5 (DMADDM 5%), G12.10 (DMADDM 10%), G16.5 (DMAHDM 5%), G16.10 (DMAHDM 10%). One group was used as control group (CG 0%). Degree of conversion (DC); water sorption (WS) and solubility (SL); hygroscopic expansion (HE); degradation temperature (DT); glass transition temperature (Tg) and polymerization shrinkage (PS) were determined. Knoop hardness (KNH), flexural strength (FS) and elastic modulus (EM) were measured before and after storage Data were submitted to ANOVA and Tukey's test (p≤0.05). RESULTS:DC ranged between 76.1 (G12.10) and 70.7 (G16.5) %; CG had the lowest WS, SL and HE. There was no statistical difference for PS and FS. KHN values ranged between 30.2 (GC) and 25 (G16.10) and after storage the performance was depended on QAS concentration and chain length. For EM, CG had the highest values before and after storage and no difference was observed in the QAS groups before storage. After storage, the results were dependent on QAS concentration (3.5-4.3GPa). SIGNIFICANCE: In general, the addition of QAS increased composite's degradation compared with the CG. In the tested QAS, the addition of DMADDM at 5% concentration resulted in a less degradable material.
Authors: Wen Zhou; Xinyu Peng; Xuedong Zhou; Andrea Bonavente; Michael D Weir; Mary Anne S Melo; Satoshi Imazato; Thomas W Oates; Lei Cheng; Hockin H K Xu Journal: Int J Mol Sci Date: 2020-09-02 Impact factor: 5.923