IADR Abstract Archives
Improving Polymethyl Methacrylate Denture Material (PMMA) with Novel Nano-ceramic Coatings
Objectives: Objectives: PMMA is widely used as denture base material. However, its porous hydrophobic surface is susceptible to scratching and decomposition during mechanical and chemical cleaning. Our objectives in this study are to modify PMMA surface with novel nano-ceramic coatings (TiO2, ZrO2 or mixed TiO2-ZrO2) to improve the mechanical, chemical and surface properties of PMMA with non-coated PMMA as control.
Methods: Methods: Atomic layer deposition (ALD) was used for depositing nano-ceramic coatings on PMMA surface due to its high accuracy in controlling thickness at Angstrom scale. A sessile drop method was used to perform water contact angle (WCA) measurements to monitor the wettability s of coated-PMMA. The chemical composition, morphology and micro-hardness of PMMA before and after nano-ceramic coatings were investigated with X-ray photoelectron spectroscopy (XPS), scanning electronic microscope (SEM) and the Vickers hardness. The bonding of nano-ceramic coatings to PMMA was tested with mechanical testing (5000 strokes of toothbrushing and sonication), chemical cleansing challenge (Polident).
Results: Results: Thirty-nanometer thin film of TiO2, ZrO2 or mixed TiO2-ZrO2 were successfully deposited on PMMA surface at 100°C-120°C. XPS and SEM results show the effective presence of the nano-ceramic on PMMA surface and within the polymer body. Surface morphology was not significantly altered. All coated surfaces become stable and hydrophilic after ALD coating and DI water storage for two weeks. The surface Vickers hardness of coated PMMA (TiO2: 38.2, ZrO2: 35.1, mixed TiO2-ZrO2: 42.4) increased significantly compared to that of untreated PMMA (24.2) (n=6, p<0.05, t test). After four hours sonication in Polident and 5000 strokes of toothbrushing, XPS results shows the nano-ceramics were still present on the PMMA surface.
Conclusions: Conclusions: ALD is a promising technique to deposit durable and conformal nano-ceramic coatings on PMMA at the Angstrom scale. These nano-ceramic coatings improve PMMA’s surface wettability, hardness and wear resistance without altering surface morphology.
Methods: Methods: Atomic layer deposition (ALD) was used for depositing nano-ceramic coatings on PMMA surface due to its high accuracy in controlling thickness at Angstrom scale. A sessile drop method was used to perform water contact angle (WCA) measurements to monitor the wettability s of coated-PMMA. The chemical composition, morphology and micro-hardness of PMMA before and after nano-ceramic coatings were investigated with X-ray photoelectron spectroscopy (XPS), scanning electronic microscope (SEM) and the Vickers hardness. The bonding of nano-ceramic coatings to PMMA was tested with mechanical testing (5000 strokes of toothbrushing and sonication), chemical cleansing challenge (Polident).
Results: Results: Thirty-nanometer thin film of TiO2, ZrO2 or mixed TiO2-ZrO2 were successfully deposited on PMMA surface at 100°C-120°C. XPS and SEM results show the effective presence of the nano-ceramic on PMMA surface and within the polymer body. Surface morphology was not significantly altered. All coated surfaces become stable and hydrophilic after ALD coating and DI water storage for two weeks. The surface Vickers hardness of coated PMMA (TiO2: 38.2, ZrO2: 35.1, mixed TiO2-ZrO2: 42.4) increased significantly compared to that of untreated PMMA (24.2) (n=6, p<0.05, t test). After four hours sonication in Polident and 5000 strokes of toothbrushing, XPS results shows the nano-ceramics were still present on the PMMA surface.
Conclusions: Conclusions: ALD is a promising technique to deposit durable and conformal nano-ceramic coatings on PMMA at the Angstrom scale. These nano-ceramic coatings improve PMMA’s surface wettability, hardness and wear resistance without altering surface morphology.