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Effect of moisture protective coatings on the strength of a modern metal‐reinforced glass–ionomer cement
Author(s) -
Williams J. A.,
Billington R. W.,
Pearson G. J.
Publication year - 1998
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1046/j.1365-2842.1998.00282.x
Subject(s) - glass ionomer cement , cement , materials science , composite material , moisture , ionomer , metal , metallurgy , polymer , copolymer
SUMMARY The strength of a modern, low metal : glass ratio, metal‐reinforced glass–ionomer cement was measured evaluating a number of protective barriers: one light‐cured resin, two solvent‐based dental varnishes and petroleum jelly. The cement was exposed to water at 10 and 60 min from start of mix. The results obtained with these protecting agents were compared with those obtained where no protection was applied. A comparison of uniaxial flexural strength and biaxial flexural strength showed the latter to be more discriminating. Proprietary dental varnishes were superior to petroleum jelly, producing similar strengths of 50 MPa. Petroleum jelly was, however, preferable to no protection. Moisture protection during the first 30min was found to be beneficial, thereafter no further strength increase was found. A second material, a cermet which has a high metal : glass ratio, was found to be more moisture resistant but weaker in strength than the modern material, with a biaxial strength of 39 MPa.