Evaluation of the effect of conventional varnish and nano-silver containing varnish on microleakage of amalgam restoration

Microleakage is one of the most important problems in dentistry. Varnish is commonly used to reduce microleakage. Nanotechnology has recently produced cosmetic dental materials with better mechanical properties. The aim of this study was to compare the microleakage of dental restorations using traditional varnish and varnish containing nano-silver. In this research study، for preparing a nano-silver varnish، nano- silver powders was added to soluble varnish with a certain weight standard. Then، 30 teeth were divided into three groups for each time period (3 days and 1 month): nano silver-containing varnish، varnish، and without varnish (control group). For each sample، two class 5 cavities were prepared (one side of the buccal and lingual) with appropriate dimensions and optimum turbine and in each cavity (except to control) suitable varnish was applied and the cavities was filled with amalgam. Then، the teeth immersed in water for 3 days and 1 month depending on related groups. After the appropriate time has elapsed، the teeth were thermo-cycled. The teeth were placed in 2% Fushin. The teeth were divided into two halves from the middle of class 5 cavity. The sections were evaluated by stereomicroscope and dye penetration was measured. The data were analyzed by Two-Way ANOVA and Tukey multiple comparison test. Tukey multiple comparison analysis showed that there was a significant difference between nano-silver containing varnish group and two other groups. Based on the results of this study، applying of nano-silver to varnish reduces microleakage in amalgam restoration.