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Title:	Physical, mechanical and radiopacity properties of denture base poly (methyl methacrylate) filled with titanate-treated nanobarium titanate
Authors:	Nidal Wanis Elshereksi (P68267)
Supervisor:	Che Husna Azhari, Prof. Dr.
Keywords:	Poly (methyl methacrylate) Dental base material Nanocomposites Nanobarium titanate Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	8-Aug-2017
Description:	Poly (methyl methacrylate) (PMMA) is the material of choice for denture base construction. However, the application of PMMA as an ideal dental base material is still restricted by a few limitations such as poor strength and radiopacity. The aims of the present study are to enhance the hydrolytic stability of denture base nanocomposites by using titanate coupling agent (TCA) as an alternative coupler to silane. The utilisation of nanobarium titanate (NBT) as reinforcement and radiopacifier agents in PMMA denture base material is also investigated. The NBT was treated by TCA, isopropyl tri[di(octyl) phosphate] titanate, and characterised via Fourier transform-infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis before and after surface modification. Various ratios (0, 1, 3, 5, 7, and 9 wt.%) of the treated filler were used. The powder and liquid of acrylic resins were mixed with the ratio of 2.5:1 by weight with sonication of 20 min for NBT-containing monomer preceded mixing. Moulds were filled with the mixture and subjected to pressure at 14 MPa for 25 min. The curing was carried out using a water bath at 75°C for 1.5 h and then elevated to the boiling point for 30 min. The samples were tested for tensile, flexural properties, fracture toughness and hardness. The morphology of the specimens was examined using field-emission electron scanning microscopy (FESEM). The results showed that the incorporation of 5wt.% of NBT into PMMA matrix exhibited the highest values of tensile and flexural strength, and fracture toughness (65.7 MPa.m1/2, 100.2 MPa.m1/2 and 1.75 MPa.m1/2, respectively). The surface hardness of PMMA nanocomposites was markedly enhanced as a function of filler loading. FESEM images displayed that, at lower ratios (1-5 wt.%), the NBT particles were embedded in the matrix with good dispersion and interfacial bonding. A tendency to agglomerate was observed at higher filler loading (7-9 wt.%). Studies on absorption and solubility in water and simulated body fluid (SBF) revealed that the filled samples showed lower solubility and absorption as compared to the unfilled samples. The effects of environmental condition on the surface hardness and the fracture toughness were also studied. Although no notable change in surface hardness of PMMA matrix and PMMA nanocomposite was observed after 60 days of immersion, enhancement in fracture toughness was found (1.65 MPa.m1/2 and 1.95 MPa.m1/2 respectively). Moreover, TCA exhibited better stability in moisture than silane by minimising the titanated NBT leachability which could lead to the promotion of the clinical longevity of the nanocomposite. The radiopacity of NBT/PMMA nanocomposites was enhanced when the filler percentages increased. This study suggested that radiopacity of NBT/PMMA remains unaltered after 3-months immersion in SBF.,Ph.D.
Pages:	181
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

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