ABSTRACT
STATEMENT OF PROBLEM: Polymethyl methacrylate (PMMA) is the most regularly used material in denture fabrication. Water sorption of denture base PMMA denture base resin has negative effects on physical properties, may lead to harmful tissue reactions in patients, and also has detrimental effects on color stability of the denture base. PURPOSE: The purpose of this study was to evaluate the effect on water sorption of heat-cured PMMA denture base material after incorporation of 1%, 3%, and 5% by weight of silanized titanium dioxide (TiO2) nanoparticles. MATERIALS AND METHODS: For preparation of test samples, TiO2 nanoparticles (PCode: 700339, Sigma-Aldrich, USA) were coated with a layer of trimethoxysilylpropylmethacrylate (PCode: 440159, Sigma-Aldrich, USA) before sonicated in monomer (MMA) (DPI Heat Cure) with the percentages 1%, 3%, and 5% by weight; after sonication, it was mixed with PMMA powder using conventional denture fabrication procedure. Then, we prepared total 40 samples for study; 10 samples for each four groups, i.e. that is one control group and three experimental groups. The first group was prepared from PMMA without addition of TiO2 nanoparticles (control group), the second group with the addition of 1 wt% TiO2 nanoparticles, the third group with 3 wt% TiO2 nanoparticles, and the fourth one with 5 wt% TiO2 nanoparticles (experimental groups). Water sorption test was then conducted on each sample. RESULTS: Each group was evaluated for water sorption test, and it was found that increasing the wt% of nanoparticles, there was a significant decrease in water sorption of denture base resin from 1.74 to 1.46 mean wt%. P value suggested that the difference of mean percent increase across all groups was statistically significant with P = 0.034. CONCLUSION: The maximum decrease in water sorption was observed in denture base resin incorporated with 5 wt% TiO2 nanoparticles.
ABSTRACT
INTRODUCTION: Impression making is one of the most important steps in prosthodontic rehabilitation of edentulous patients. Zinc oxide eugenol (ZOE) impression paste is the most commonly used material for complete denture wash impression due to its cost-effectiveness and ease of manipulation, while providing the advantage of ability to record fine minute tissue details. Rheological property like flow is a critical factor influencing the success of any impression material, especially in intraoral conditions. Therefore, with so many brands of commercially available impression materials flooding the markets, the aim of this study was to evaluate and compare the flow property of four commercially available ZOE impression materials under simulated intraoral condition. MATERIALS AND METHODS: The testing method used was according to the American Dental Association (ADA) specification no. 16 for ZOE impression pastes. RESULTS: At room temperature, maximum flow was seen with Denzomix followed by Dental Product of India (DPI), Neogenate, and Cavex in descending order, respectively, at 30 s, 1 min, and 10 min of load application. At 37°C in saliva, maximum flow was seen with Denzomix followed by Neogenate, DPI, and Cavex in descending order, respectively, at 30 s, 1 min, and 10 min of load application. Of the four ZOE impression pastes, only the flow of Cavex was considerably less than ADA specified value. INTERPRETATION AND CONCLUSION: Results obtained from this study showed that there is considerable variation in the flow values of different commercially available ZOE impression materials. Change in temperature and presence of saliva had a significant influence on the flow of ZOE impression materials.
ABSTRACT
The loss of an eye is a traumatic and common event. The psychological effects of losing an eye are frequently more difficult to deal with than its functional loss. This article describes the management of a child patient with anopthalmic socket, by an innovative technique of customizing the stock acrylic resin ocular prosthesis to get improved esthetics, accurate location of iris-pupil complex and exact fit in the defect.
