Radiofrequency Glow Discharge as a Mode of Disinfection for Elastomeric Impression Materials.

INTRODUCTION: Prosthodontic practice involves procedures in which impressions of the maxillary and mandibular arches are mandatory. Cross infection is one of the major problems that can occur in regular dental practice. Every dentist should take utmost care to prevent cross infection as oral cavity is the source of variety of microorganisms which can often cause diseases that can be fatal. Although precautions, such as wearing of gloves and mask, sterilization of instruments are given importance, the need for disinfection of impressions is often neglected. Hence, the aim of the study was to assess the disinfection potential of radiofrequency glow discharge (RGD) by microbiological studies. MATERIALS AND METHODS: Disinfection potential of RGD on addition silicone (Reprosil, Dentsply, Milford DE, USA) was assessed. Total sample size was 20. Samples were divided into two groups of 10 each. Group I - control group and group II -RGD-treated group. Main groups were subdivided into subgroups A and B. Data collected were analyzed. RESULTS: The RGD-treated samples were found to be culture sterile which meant that there were no signs of growth of any organisms, thus proving the disinfection potential of RGD. CONCLUSION: From this study, we can conclude that RGD is a very rapid and handy device, which can disinfect saliva contaminated elastomeric impression material surfaces. CLINICAL SIGNIFICANCE: When compared with the difficulties and lack of efficiency encountered in disinfecting impressions by immersion and spray atomization, RGD can be very handy in dental clinics, as it is a very rapid and convenient method for infection control.

Effect of Recasting on Physical Properties of Base Metal Alloys: An In Vitro Study.

AIMS AND OBJECTIVES: This study aims to establish the outcome of recasting on tensile strength, modulus of elasticity, and hardness of Nickel-chromium alloys. MATERIALS AND METHODS: Fifty wax patterns were fabricated, using the lost wax technique, the measurements of which were standardized. They were categorized into five groups of ten each. Group I included samples casted with new alloy alone. Group II samples consisted of 75% new alloy and 25% once casted alloy. Group III was casted with 50% of each. Group IV with 25% new metal and 75% previous alloy and samples of Group V samples were casted with once casted alloy alone. Modulus of elasticity and tensile strength were measured by universal testing machine, whereas hardness using microhardness tester. The values were statistically analysed. IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. IBM Corp, Armonk, NY, USA. for Windows software was used for analysis. RESULTS: We found a slight variation in mean tensile strength and modulus of elasticity, which was statistically insignificant variation among the groups. However, there was a significant difference in mean hardness between Groups III, IV, and V. CONCLUSION: It is prudent to use pure alloy alone for casting. However, in view of environment and economical factors, addition of <50% reused alloy to pure alloy is satisfactory clinically.