Marginal leakage of class V cavity preparations

Dentin-bonding materials, ferric oxylate (FO), addition reaction between N-phenylglycine and glycidyl methacrylate (NPG-GMA), and addition reaction product of pyromellitic acid dianhydride and 2-hydroxyethyl methacrylate (PMDM), were tested together for their ability to inhibit marginal leakage in Class V composite restorations in vitro. Sixteen experimental teeth were pretreated with FO, NPG-GMA, PMDM, and restored with composite. Sixteen control teeth were treated conventionally with composite. The teeth were then thermally cycled (5 and 55 degrees C) for 7 days, silver stained, and evaluated blindly for degree of marginal leakage on a scale of 0 (no leakage) to 7 (leakage into the pulp). The experimental group displayed significantly greater leakage values (p less than 0.01) than controls. The results of this study support the hypothesis that FO, NPG-GMA, and PMDM, together with composite inhibit marginal leakage.