ABSTRACT
AIM: To evaluate the shear bond strength and failure mode of total-etch and self-etch bonding agents on human dentin with and without application of 2% chlorhexidine gluconate (CHX). MATERIALS AND METHODS: Eighty extracted premolars were chosen and stored in 10% formalin until use. Samples were mounted in cold cure acrylic resin and the occlusal enamel perpendicular to long axis of each tooth was removed using a low-speed diamond saw under water coolant. The prepared teeth were randomly divided into four groups of 20 samples each according to the adhesive system used. Groups 1 and 2 were the control group in which total-etch and self-etch adhesives were applied as per manufacturer's instructions, Groups 3 and 4 were the experimental groups in which 2% CHX was applied and blot dried prior to the application of total-etch and self-etch adhesives. A custom-designed rig was fabricated to place composite on samples. The customized rig comprised a cylindrical mold with height of 3 mm and internal diameter of 2.5 mm. Resin was placed in increments of 1 mm and was cured after each increments. After the composite placements, samples were placed in distilled water at 37°C for 24 h. The samples were then thermocycled between 5°C and 55°C in water with a dwell time of 30 s in each temperature to a total of 10,000 cycles. The shear test was performed using universal testing machine and fracture modes were evaluated using stereomicroscope. RESULTS: Both the experimental total-etch and self-etch groups showed better shear bond strength than the control groups, which was statistically significant, and also the least mode of failure at the adhesive interface was observed in both the experimental groups. CONCLUSION: 2% Chlorhexidine gluconate effectively improved the shear bond strength and helped maintaining the durability of adhesive interface in both total-etch and self-etch adhesives.
ABSTRACT
AIM: The aim is to recycle mercury from dental amalgam scrap using the vacuum distillation method. MATERIALS AND METHODS: A total of 150 g of dental amalgam scrap was taken in a round bottom flask and was subjected to vacuum distillation at 398°C. The vapor of mercury was collected in another round bottom flask. OBSERVATION: The procedure is carried out for mercury recovery using vacuum distillation apparatus, and mercury vapor are collected in a round bottom flask, and the silver is recovered using sucrose as reducing agent. Using 150 g of dental amalgam scrap 50%-80% of silver are recovered, and silver has a purity of 70%-80%. However, the total time required in the reduction process ranged between 303 and 600 min. CONCLUSION: Mercury could be recycled from dental amalgam scrap through vacuum distillation method at 398°C and its implication of dental amalgam scrap in an Indian perspective.
