@Article{, title={Fitness Accuracy of Modified Heat Cured Acrylic Resin}, author={Nada Z Mohammed}, journal={Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان}, volume={13}, number={2}, pages={309-319}, year={2013}, abstract={Aims: To determine the effect of addition of some chemical materials into heat cured acrylic resin denture base , the effect of storage periods and immersion media on its fitness accuracy. Materials and Methods: Fifty samples of heat cured acrylic resin denture base were prepared and divided into two groups: Control group( 10 samples without additives) and experimental group (40 samples with additives: 1% Chlorohexidine gluconate , 1.5% Nigella oil , 1.5% Thyme oil and 20% Plasticizer and caramel ) immersed in tap or distilled water for (1 week, 1 month, 3 months and 6 months. For fitness accuracy measurement , the surface area of the gap occurred between the posterior border of the denture base and the posterior margin of the stone cast were recorded by digital camera and measured with AutoCAD program .The collected data of fitness accuracy were subjected to the descriptive analysis (mean and standard deviation),one way analysis of variance (ANOVA), Duncan Multiple range test and 2 sample t-test at p<0.05. Results: The results of this study revealed that the incorporation of these chemical materials into heat cured acrylic resin increases its fitness accuracy . The highest value of fitness accuracy was achieved with the addition of 20% Plasticizer and caramel . The highest value of fitness accuracy was achieved after 6 month of immersion . Fitness accuracy of control and experimental groups immersed in tap water was better than that in distilled water. Conclusion: The additive materials, storage periods and immersion media had significant effect on fitness accuracy of denture base. The magnitude of this effect varies according to the type of additive materials, storage periods and immersion media. The highest value of fitness accuracy was achieved with experimental group of 20% Plasticizer& caramel after 6 months of immersion in tap water .

} }