Physiomechanical Properties of Denture Base Resin Reinforced with Nanoparticles and Fibres

  • Abdulaziz Alhotan

Student thesis: Phd

Abstract

Polymethyl methacrylate (PMMA) is commonly employed as a denture base material. However, there are many mechanical and physical challenges associated with the use of PMMA for the denture bases. This study aimed to evaluate the effect of ZrO2, TiO2 nanoparticles (NPs), and E-glass fibres at various concentrations (wt.%) on the mechanical and physical properties of the heat-cured PMMA. Fillers were silanated before mixed with PMMA. There were four main Groups. The control group (Group C), was non-reinforced PMMA, while Groups Z, T, and E were PMMA reinforced with ZrO2 NPs, TiO2 NPs, and E-glass fibre, respectively. The reinforced PMMA groups were further subdivided according to four filler concentrations in each case (1.5%, 3.0%, 5.0%, and 7.0% wt.%). The flexural strength, hardness, fracture toughness, and impact strength for all Groups were tested after storing in distilled water at 37˚C for 7d. A three-point bending test was used to measure the flexural strength and fracture toughness, while a Charpy impact test and a Vickers hardness test were employed to test the impact strength and surface hardness, respectively. The fractured surface of the specimens was evaluated using a Scanning Electron Microscope (SEM). Furthermore, the specimens from each group were stored in distilled water at 37±1°C for 180 d to evaluate the water sorption/solubility and hygroscopic expansion properties. Water sorption/solubility were calculated using an electronic balance, while 3D hygroscopic expansion was measured using a laser scanning micrometre. In addition, specimens were immersed in SteradentTM (STD) and coffee (CF) solutions at 37±1°C for 180 d to test colour stability using a Minolta Chroma Meter. The results were analysed with different statistical methods at a p≤0.05 significance level. The findings revealed that the filler concentrations that had the most significant positive influence on the flexural strength of the PMMA were 3 wt.% ZrO2 and 5–7 wt.% E-glass fibre. The surface hardness of PMMA significantly increased when the filler concentration was 3 wt.% or higher. Fracture toughness significantly increased by incorporating 1.5 and 3 wt.% ZrO2, 1.5 wt.% TiO2, and 1.5-7 wt.% E-glass fibre concentrations into the PMMA. The addition of E-glass fibres in PMMA significantly enhanced the impact strength, but the addition of TiO2 or ZrO2 did not. The water solubility/sorption and hygroscopic expansion of PMMA were not improved by adding E-glass fibres or ZrO2 NPs, but significantly increased with TiO2. The colour stability of all tested specimens was impacted to various significant and non-significant degrees in accordance with the filler type, filler percentage, duration of storage, and storage medium.
Date of Award1 Aug 2022
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorJulfikar Haider (Supervisor), Nick Silikas (Supervisor) & Julian Yates (Supervisor)

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