EFFECT OF SILANIZED ZIRCONIA ON SOME MECHANICAL PROPERTIE S OF HEAT -POLYMERIZED POLY METHYLMETHACRYLATE DENTURE BASE MATERIAL | ||||
| Egyptian Dental Journal | ||||
| Article 7, Volume 64, Issue 4 - October (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics), October 2018, Page 3583-3592 PDF (868.33 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/edj.2018.79181 | ||||
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| Authors | ||||
| Hend E Elkafrawy; Nancy S Farghal | ||||
| Lecturer of Dental Biomaterials, Faculty of Dentistry, Tanta University, Egypt | ||||
| Abstract | ||||
| Objective: The purpose of this work was to study the effect of addition of silanized zirconia powder on flexural strength, deflection, modulus, toughness and micro-hardness of heat-polymerized poly methyl methacrylate (PMMA) denture base resin. Materials and Methods: One hundred specimens of heat-polymerized PMMA were prepared for flexural and hardness tests, fifty for each. Zirconia (ZrO2) powder was treated with silane coupling agent then added to acrylic powder in percentage of 0%(control), 0.5%, 1%, 2% and 5% by weight. Specimens for flexural test were prepared in the shape of flat strips with dimensions of (65×10×2.5mm) using compression molding technique. Flexural test was performed by three-point bending test using universal testing machine. Flexural strength, flexural deflection, flexural modulus and toughness were obtained from the software of the testing machine. Specimens for microhardness test were prepared in dimensions of (10×10×3mm). Micro-hardness was determined using Vickers Micro-hardness Tester. Digital microscope was used to capture photomicrographs at x500 magnification of the surface of randomly selected specimen for each group to show the distribution of different percentages of zirconia. One-way Anova followed by Scheffe’s post hoc multiple comparison test was performed with 5% level of significance for testing the significance between the means of tested groups. Results: There is a significant difference among the mean values of flexural deflection, flexural modulus, toughness and micro-hardness (P<0.05%). The mean values of flexural strength were not significantly different (P>0.05%). The digital microscope has shown nearly even distribution of zirconia particles within the acrylic matrix at 0.5% and 1%, while clusters started to form at 2%, and 5% zirconia. Conclusion: Silanized zirconia powder could be used to improve the properties of heatpolymerized acrylic denture base resin. The most appropriate percentages were 1% and 2%. | ||||
| Keywords | ||||
| Zirconia powder; Silane coupling agent; Modified denture acrylic resin; Flexural test; Micro-hardness | ||||
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