Inita, N G (2022) Evaluation of Flexural Strength of Heat Cure Denture Base Material Reinforced with 1wt% of Different Nanoparticles and Sizes: An Invitro study. Masters thesis, Sree Mookambika Institute of Dental Sciences, Kulasekharam.
Full text not available from this repository.Abstract
PURPOSE: To evaluate the effect of adding 1wt% of Al2O3, SiO2, and ZrO2 nanoparticles to heat cure acrylic resins on their flexural strength. INTRODUCTION: PMMA has been the material of choice for denture base materials because of its ease of use, low cost, esthetics, polishability, light weight. But the material has the disadvantage of low mechanical properties such as low flexural strength and impact strength resulting in fracture of the denture when subjected to occlusal forces. Reinforcement with fibres, metal oxides, wires have been tried to improve the mechanical properties. Recent advancements in the field of nanotechonology has enabled the application of nanoparticles for the mechanical reinforcement of PMMA to improve its mechanical properties. Nanoparticles are considered effective reinforcing materials. Nano particles are used as fillers in polymeric materials to improve the mechanical properties. The Nanoparticles are characterized by the small size, large specific surface area, and strong interfacial interaction with organic polymers. The dimension of the material is in nanometer dimension, which leads to unique properties. The purpose of the study is to evaluate the flexural strength of heat cure PMMA on adding 1wt% of Al2O3, SiO2, & ZrO2 of diameter 5nm and 15nm. MATERIALS AND METHODS: A total of 88 specimens are prepared in 4 groups (Control, 1wt% Al2O3, 1wt% SiO2, 1wt% ZrO2) and 3 subgroups (5 nm & 15 nm of all Nano groups) (n =22/group). The PMMA powder and nanoparticles are mixed with each other by means of ball milling at 350 rpm for one hour. The templates of dimension 65mm length, 10mm width, 3 mm thickness is invested in type III dental stone. The powder liquid ratio is followed according to the manufacturers ratio as 20ml for 43.8g. The material is mixed and placed in the mould which is then placed under hydraulic press. The flask is then kept in water bath for curing. It is placed for two hours and then boiled for one hour. Then the specimens are deflasked trimmed and policed. The specimens are polished with 200-, 400-, and 600-grit abrasive paper to provide a standard surface before testing and then suspended in distilled water. Flexural strength is measured via three-point bending tests. Subsequently, SEM analysis is performed for specimens from each group to ensure homogenous distribution. RESULTS: The flexural strength of polymethylmethacrylate (PMMA) after adding 1wt% of aluminum trioxide 15nm significantly increased (p ˂ 0.05) followed by 1wt% of silicon dioxide 15nm. The electron microscopy analysis revealed that the particles were homogeneously dispersed in PMMA matrix. CONCLUSION: The mechanical properties of heat cure PMMA can be increased by addition of nanoparticles to PMMA powder. 1wt% of aluminium trioxide-15nm diameter has significantly improved the flexural strength of PMMA.
| Item Type: | Thesis (Masters) |
|---|---|
| Additional Information: | 241911301 |
| Uncontrolled Keywords: | Nanoparticles, Flexural Strength, PMMA, Aluminium Trioxide, Silicon Dioxide, Zirconium Dioxide. |
| Subjects: | DENTAL > Prosthodontics and Crown and Bridge |
| Depositing User: | Subramani R |
| Date Deposited: | 08 May 2022 15:40 |
| Last Modified: | 20 Aug 2022 13:33 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/19980 |
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