The Effect Of Denture Base Resins Coated With Antibacterial Coating On Water Sorption, Solubility And Monomer Eiution

Heat-curing acrylic resins, which are commonly used for denture prosthetictreatment, are usually composed of prepolymerized polymethyl methacrylate (PMMA)powder particles and mixed with methyl methacrylate (MMA) monomers. In spite ofthe various polymerization methods, the conversion of monomers to polymers is notcomplete and there are some unreacted monomers left in the denture base resins.During clinical use, the denture base resins are either immersed in saliva or denturecleansing solutions and water. Water absorption and monomer elution from denturebase resins will been found. Water molecules may penetrate inside the polymer matrixand act as a plasticiser, thus reducing mechanical properties of the denture base resins.In this study, we synthesized a silver-loaded nanosilica antibacterial particle,which mixed with a kind of organic-inorganic hybrid coatings. Then theorganic-inorganic hybrid coating was cured on the surface of the denture base resins.The aim of this study was to identify and quantify the water sorption, solubility andmonomer elution of denture base resins, and investigate whether the organic-inorganichybrid coatings could effectively diminish the leaching of residual monomers. Wemay provide some references for the clinical application of new coating for denturebase materials.The values of water absorption and solubility was measured according to YY0270-2003and gas chromatography was used to examine the leachability of fourcommercially available heat-cured acrylic resins between experimental groups andcontrol groups. Degree of crosslinking of the experimental heat-cured acrylic denturebases was measured by soxhlet extraction method.Experimental results showed that differences in the values of water absorptionand solubility within each material were tested for significance using independent samples t test. The values of water sorption, solubility of experimental group werelower compared to the control groups. There wasn’t an interaction between the resinbrand and antibacterial coating. Based on one-way anova anaysis, the value of waterabsorption and solubility of Heraeus groups were lower than the other groups（P<0.05）before coated specimens with antibacterial coating and there is nodifference among the four materials, after coated specimens with antibacterial coating（P<0.05）.Degree of crosslinking of Heraeus was the highest among theexperimental heat-cured acrylic denture bases. The amount of leached compoundsamong intervals were tested for significance using independent samples t test. Thevalues of monomer elution of experimental groups were significantly lower than thecontrol groups（P<0.05）.The results revealed that there is a same trend existing among water absorption,degree of crosslinking and the monomer elution. Degree of crosslinking increased,thus the values of water absorption and monomer elution decreasing. Antibacterialcoating could significantly reduce the values of water absorption and solubility aswell as monomer elution improving the comprehensive properties of the denture baseresins.