Glycerol-dimethacrylate as alternative hydrophilic monomer for HEMA replacement in simplified adhesives. (June 2018)

• Record Type: Journal Article
• Authors: Araújo-Neto, V.G.; Nobre, C.F.A.; De Paula, D.M.; Souza, L.C.; Silva, J.C.; Moreira, M.M.; Picanço, P.R.B.; Feitosa, V.P.
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 82(2018)
• Page Start: 95
• Page End: 101
• Publication Date: 2018-06
• Subjects: Dentin -- Polymerization -- Biomaterials; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2018.03.022
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Objectives: Hydroxyethyl-methacrylate (HEMA) is still widely used in simplified adhesives. Indeed, several shortcomings occur with this monomer, such as water uptake and formation of linear polymers. This study aimed to compare the effects of HEMA replacement by glycerol-dimethacrylate (GDMA) on selected physicochemical properties and bonding performance of simplified model adhesives. Materials and Methods: Experimental simplified etch-and-rinse and self-etch adhesives were formulated containing 20 wt% HEMA or GDMA. Three-point bending test was used to obtain the elastic modulus of bar-shaped specimens, and water sorption and solubility were attained by ISO-4049(ISO, 2009) method. Degree of conversion was surveyed by Micro-Raman spectroscopy, and microtensile bond strength was tested after 24 h or 6 months simulated pulpal pressure aging. Statistical analysis was realized with two-way ANOVA and Tukey's test (p < 0.05). Results: GDMA promoted higher elastic modulus to the self-etch adhesive, and GDMA-containing etch-and-rinse adhesive achieved overall lower water sorption and solubility. The degree of conversion was statistically higher for GDMA adhesives than for HEMA etch-and-rinse one. All bond strengths dropped significantly after aging, except that of GDMA self-etch adhesive. The nanoleakage was higher and gaps were found in the interface of HEMA-containing adhesives, which were less present in GDMA equivalents. Conclusions: GDMA is a feasible hydrophilic dimethacrylate monomer to replace HEMA in simplified adhesives, thereby providing better polymerization, mechanical properties and dentin adhesion as well as lower water uptake and solubility. Graphical abstract: fx1 Highlights: A low-molecular weight hydrophilic dimethacrylate (GDMA) was tested to replace HEMA. Adhesion, elastic modulus, conversion, water sorption and solubility were surveyed. GDMA achieved higher physical properties with lower water uptake and solubility. GDMA in a model self-etch adhesive attained stable dentin bond after aging.