Once again, one is dealing here with a class of materials described in Section II. B.5 as luting agents, and indeed the only major difference compared to luting agents is that of consistency, the polycarboxylates used as cavity base or lining materials having a higher viscosity as a consequence of a higher concentration of the aqueous poly(acrylic acid) solution. Because of the possibility of pulp irritation by the free polyacid present in the uncured material, use of the polycarboxylates is generally restricted to the lining of shallow cavities unless the linings are underlaid by protective calcium hydroxide or ZOE sublinings. As pointed out before, the polycarboxylates stand out against the phosphates and chelating cements because of their capability of bond formation between carboxyl groups and apatitic calcium cations of enamel and dentin. Compressive strength values of the hardened cement materials typically attain 90 MPa.
Polycarboxylates
10 октября, 2015 Malyar