Physical and chemical properties of model composites containing quaternary ammonium methacrylates. Issue 1 (January 2018)

• Record Type: Journal Article
• Authors: Vidal, Marina Lermenn; Rego, Guilherme Ferreira; Viana, Gil Mendes; Cabral, Lucio Mendes; Souza, Juliana Primo Basílio; Silikas, Nick; Schneider, Luis Felipe; Cavalcante, Larissa Maria
• Is Part Of: Dental materials. Volume 34:Issue 1(2018)
• Page Start: 143
• Page End: 151
• Publication Date: 2018-01
• Subjects: Composite -- Dental resin -- Mechanical properties -- Physical properties -- Chemical properties -- Quaternary ammonium methacrylates; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2017.09.020
• Languages: English
• ISSNs: 0109-5641

Abstract

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 (3.5-4.3 GPa). 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.