Resin glass polyalkenoate cement composition

Fracture toughness values for glass polyalkenoate cement vary from 0-25 to 0-55 MN (Lloyd Mitchell, 1984 Goldman, 1985 Lloyd Adamson, 1987). The values are generally higher than those found for the traditional dental silicate cement but lower than those found for anterior composite resins (Lloyd Mitchell, 1984 Goldman, 1985) and much lower than those for posterior composite resins and dental amalgams (Lloyd Adamson, 1987). 

Figure 5.21 The laminate restoration, showing the glass polyalkenoate cement as a dentine substitute and a composite resin as an enamel substitute.

McKinney, Antonucci Rupp (1987) found that the clinical wear of the glass polyalkenoate cement compared favourably with that of the composite resin, but they noted that it was prone to brittle fracture and chemical erosion. 

A fundamental criticism of the resin-modified glass polyalkenoate cements is that, to some extent, they go against the philosophy of the glass polyalkenoate cement namely, that the freshly mixed material should contain no monomer. Monomers are toxic, and HEMA is no exception. This disadvantage of composite resins is avoided in the glass polyalkenoate cement as the polyacid is pre-polymerized during manufacture, but the same cannot be said of these new materials. For this reason they may lack the biocompatibility of conventional glass polyalkenoate cements. These materials also absorb excessive amounts of water because of the hydrophilic nature of polyHEMA (Nicholson, Anstice McLean, 1992). 

Glass polyalkenoate (glass-ionomer) cement Bonding to composite resins... 

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