MACROMOLECULAR LEAKAGE BENEATH FULL CAST CROWNS - PART III - THE DIFFUSION OF LIPOPOLYSACCHARIDE AND DEXTRAN

Statement of problem. Most microleakage studies have used low molecula r weight dyes or isotopes rather than clinically relevant materials, s uch as lipopolysaccharides or cell wall materials, that have been show n to provoke inflammatory reactions in the dental pulp. Purpose. This study evaluated the leakage (diffusion) of lipopolysaccharide and dext ran beneath cast gold crowns luted with 3 cements. Material and method s. Thirty extracted molars were prepared for crowns. Ten crowns with a ccess ports (facial or lingual) were cast in gold and luted with zinc phosphate, glass ionomer, and an adhesive resin cement onto their prep arations. Teeth and crowns with filters inserted into the ports were i mmersed in a solution of labeled macromolecules (TRITC-LPS, FITC-dextr an) and evaluated for leakage at 2 weeks, and 1, 2, 3, 4, 5, and 6 mon ths. Filters were retrieved and analyzed with fluorescent microscopy. Results. All filters retrieved from crowns luted with zinc phosphate, glass ionomer, and adhesive resin cements demonstrated no detectable l eakage and were negative for both FITC-dextran and TRITC-lipopolysacch aride at all evaluation periods. Conclusion. Leakage of lipopolysaccha rides and dextran did not occur during the period of this study. For t he length of this investigation, zinc phosphate, Ketac-Cem, and C&B-Me tabond were equally effective at preventing leakage of detectable mole cular concentrations of lipopolysaccharide and dextran to the level of the access ports.