A Study of Low Shrinkage Multifunctional Methacrylate Dental Restorative Materials for Visible-light Curing
Date Issued
2008
Date
2008
Author(s)
Huang, Chih-Hao
Abstract
By adding of polypropylene glycol (PPG) which contains three molar equivalent of hydroxyl groups, the more funtionalities will provide in the modified epoxy acrylate (EA). At the same time, by increasing the funtionalities and molecular weight of modified composite resin which crosslinking in polymerization and decreasing polymerization shrinkage. The multifuntional methacrylate resin were prepared by modified reaction of epoxy acrylate (EA). The hydroxyl groups of epoxy acrylate (EA) were reacted with modified side chain, which pre-reacted by isocyanate groups of toluene 2,4-diisocyanate (TDI), 2-hydroxyethyl methacrylate (HEMA) and polypropylene glycol (PPG) with proper molar ratio. The dental monomers were obtained. The methacrylate resin synthesis of following procedures with more functionalities than un-modified epoxy acrylate (EA). As the reaction proceeded, the reaction underwent the nucleophilic reaction and the stronger hydrogen bonding, resulted in the decrease of flowing property. By adding different ratio of tripropylene glycol diacrylate (TPGDA) in resin matrix adjust the flowing property. The dental restorative materials were composed of modified multifuntional methacrylate resin, tripropylene glycol diacrylate (TPGDA), D,L-camphoroquinone (CQ), ethyl 4-dimethylaminobenzoate (EDMAB) and inorganic particles, which chosen nano fumed silica and dispersed silica solution with different ratio. After visible light curing (410-500 nm), the composite dental material were formed and analyzed by Fourier Transform Infrared Spectrometer (FT-IR), Gel Permeation Chromatography (GPC), polymerization shrinkage test and micro-hardness test. And those data were compared with bisphenol A glycerolate dimethacrylate (Bis-GMA) as resin matrix and commercial materials. In this study, the loading of fumed silica was 80wt% and the dispersed silica solution was 80%. The later obtained higher hardness, and the maximum hardness was 53.9(Hv). Besides, the polymerization shrinkage test was lower by increasing inorganic particles adding. And also compared with bisphenol A glycerolate dimethacrylate (Bis-GMA)(lower 1/5~1/6 ) as resin matrix and commercial materials(lower 1/6), the polymerization shrinkage was much lower.
Subjects
multifunctional
dental restorative materials
visible light curing
acrylate resin
polymerization shrinkage
micro-hardness.
Type
thesis
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