permite-c and Dental-Leakage

Microleakage is an important clinical performance parameter of restorative materials. A literature review of the effect of thermocycling on microleakage revealed an incongruity of results.. The aim of this study was to describe the effect of thermocycling on microleakage in Class V Permite amalgam restorations.. Class V cavities were prepared at the mesial and distal cemento-enamel junctions of 20 extracted, sound, human molar teeth. Cavities were treated with Polyvar cavity varnish and restored with Permite amalgam as per manufacturer's directions. Teeth were randomly divided into two groups of 10 teeth each. After one day only one group was thermocycled for 500 hundred cycles (5 - 55 degrees C; dwell time of 30 seconds: transfer time of 10 seconds). Teeth were subsequently submersed in 0.5% Basic Fuchsin solution (24 hours: room temperature), then cleaned and embedded in polyester potting resin. Teeth were sectioned longitudinally along the long axis of the tooth into three slices using the Isomet low speed saw. Microleakage was scored under a light microscope at 10 times magnification.. While microleakage at cementum margins was significantly and negatively influenced by thermocycling, enamel margins appeared to be significantly unaffected.. The effect of thermocycling on the determination of microleakage was only significant at the cementum margins of Permite restorations.

Topics: Coloring Agents; Copper; Dental Amalgam; Dental Cavity Lining; Dental Cavity Preparation; Dental Cementum; Dental Enamel; Dental Leakage; Dental Restoration, Permanent; Humans; Materials Testing; Organic Chemicals; Plastic Embedding; Rosaniline Dyes; Silver; Temperature; Time Factors; Tooth Cervix

Different formulations of amalgam have physical properties that may make them behave differently in the often-contaminated root end environment. Five different brands of amalgam were evaluated for microleakage of root-end fillings placed in extracted human teeth. These included a zinc-free spherical amalgam, a zinc-free admixture amalgam, two zinc-containing admixture amalgams, and a zinc-containing lathe-cut amalgam. The amalgams were placed either into dry root-end preparations or into preparations contaminated with human blood. The fluid filtration method was used to measure microleakage at 1, 2, 4, 8, 12, and 24 wk after placement. Analysis of variance revealed significant differences in the rates of microleakage at every measurement period. Scheffé's test showed that the zinc-free spherical amalgam had significantly greater leakage than all the other products evaluated. There were no significant differences between any of the other products. Blood contamination did not adversely affect the seal of any amalgam.

Topics: Analysis of Variance; Dental Alloys; Dental Amalgam; Dental Leakage; Evaluation Studies as Topic; Humans; Retrograde Obturation; Root Canal Filling Materials; Zinc