بررسي آزمايشگاهي ميزان سايش چهار نوع دندان مصنوعي آكريلي در مجاورت بزاق مصنوعي

Wear Rate of Four Kinds of Artificial Teeth in Artificial Saliva Invironrnent (An In Vitro Study)

Introduction: Wear resistance of acrylic teeth has an important role in denture longevity. The purpose of this study was to compare the tooth wear rate of three kinds of artificial teeth manufactured in Iran with the one manufactured in Italy. Materials & Methods: In this experimental in vitro study, four kinds of artificial teeth (Italian Ivoclar, Yaghoot, Herasit plus. Acradent) were used. Nine molars were selected from each tooth. Samples were prepared as cylinders with 2.5mm diameters. The samples were thermocyeled for 2500 times (5oc~55Gc) and then scaled with l/lOo:m gram accuracy. Artificial saliva was added to wearing device and wearing was performed for 2000 cycles {125m). Samples were rescaled. The disk and saliva were exchanged and the procedure was repeated for 5000 cycles (439.6m). The rescaling was as well performed. Wcar rate was calculated for 2000 and 7000 cycles and was compared for different teeth. The data were analysed by Multivariate ANOVA and Tukey test. Results: Tooth wear after 2000 cycles was 0.018 for Ivoclar, 0.025 for yaghcot, 0.071 for Acradent and 0.379 mgr/m for Herasir. After 7000 Cycles, wear rates were 0.012. 0.019, 0.055 and 0.14 mgr/m respectively. Conclusion: Wear rate of Herasit and Acradent artificial teeth were significantly different from eachother and from Yaghoot and Ivoclar artificial teeth but Yaghoot and Ivoclar teeth had no significant difference in wear rate.