Bisphenol A-glycidyl methacrylate bis-GMA

Bisphenol A glycidyl methacrylate (bis-GMA) is an epoxy-methacrylate. Sensitization occurs in dentists. 

Some dental composite materials (Kingman et al., 2012) are based on bisphe-nol A-glycidyl methacrylate (bis-GMA) that may also contain other monomer modifiers such as bisphenol A dimethacrylate (bis-DMA) (Fung et al., 2000). BPA itself is not directly used in the composite. It is the bis-DMA and bis-GMA (the prepolymer used can have as much as 70% monomer) in the composite that can be converted into BPA and leached into the sahva of patients (within 1-3 h after dental sealant is applied) (Heisch et al., 2010). The levels reported in saliva are typically low the highest reported is 931 pgA. 

Numerous thermal analysis studies have been performed by other groups on resin composites, which are used for small anterior restorations that do not experience substantial stress and with caution for posterior teeth because of concern about wear [1-3]. The polymer matrix contains the oligomer bis-GMA (bisphenol A-glycidyl methacrylate) or urethane dimethacrylate, and triethylene glycol dimethacrylate is a diluent. Filler particles are silane-coated for chemical bonding with tire matrix. Free-radical polymerization is carried out by chemical... 

The addition-reaction product of bisphenol A and glycidyl methacrylate or an epoxy resin and methacrylic acid is bis-GMA 2,2- 7Z5 4-(2-hydroxy-3-methacryloxypropoxy)phenyl propane (Fig. 5). Bis-GMA can therefore be classified as a dimethacrylated epoxy, although it does not contain a reactive epoxy group. Bis-GMA is the most commonly used prepolymer in dental composite restorative materials. Several similar compounds have also appeared as substitutes for Bis-GMA or in addition to it in dental resins. Such dimethacrylates based on bisphenol A with various chain lengths are bis-MA 2,2- fs(4-(metha-cryloxy)phenyl)-propane, bis-EMA 2,2-i7is(4-(2-met-hacryloxyethoxy)phenyl)-propane and bis-PMA 2,2- s(4-(3-methacryloxypropoxy)phenyl)-propane. 

The first epoxy dimethacrylate, known as bis-GMA (2,2-bfs(4-(2-hydroxy-3-methacryloxypropoxy)phenyl)-propane) [CAS 1565-94-2] (Fig. 6), was developed by Bowen in 1956. bis-GMA is manufactured from DGEBA and methacryUc acid or bisphenol A and glycidyl methacrylate (Bowen 1962 Jolanki et al. 1995). Analyses have shown that epoxy di(methacrylate) products may contain DGEBA as an impurity (Kanerva et al. 1989 Henriks-Eckerman and Kanerva 1997). bis-GA (2,2-bfs[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-... 

Because of excessive shrinkage (about 5%), a high coefficient of thermal expansion, and poor abrasion resistance, these materials were replaced by a series of composite materials based on a fundamental patent by Bowen.The polymer portion was a single, densely crosslinked network formed by polymerizing the reaction product of glycidyl methacrylate with bisphenol A. The monomer, known as bis-GMA, had the structure... 

The "Bowen-monomer" Bis-GMA may be pictured as the reaction product of bisphenol-A and glycidyl methacrylate. The resultant molecule contains two hydroxyl groups. Recently, analogous monomers have been proposed which do not contain these hydroxyls. Dental restorations made with these monomers are said to be low in water uptake and water solubility. Candidate monomers would be those iit... 

There is a need to further enhance the durability of dental composite restorative and sealant materials. Dimethacrylates such as BIS-GMA (the diadduct of bisphenol A and glycidyl methacrylate) are now widely used to formulate the resin component of these materials. Some of the deficiencies of dental composites and sealants are traceable to impurities and inherent structural imperfections in the monomer systems. Structure-property studies are needed to explore ways of achieving minimal shrinkage on polymerization, reducing water sorption, promoting adhesion, generally optimizing the chemical,... 

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