Influence of Titanium Oxide Nanoparticles on the Physical and Thermomechanical Behavior of Poly Methyl Methacrylate (PMMA): A Denture Base Resin

Herein, a commercially self-curing PMMA was chosen as starting material and it was then mixed with different weight percentages (0 to 3 wt%) of nano-TiO2. The composite was prepared in a form of a thin disc specimen with 5 cm diameter and 1 mm average thickness and then characterized for elemental, functional and surface properties. The mechanical properties such as Vickers micro-hardness, average indentation diagonals, viscoelastic behavior were studied to understand the effect of TiO2 incorporation into PMMA. Functional and structural analysis did not show effect of TiO2 addition on the elemental properties of PMMA whereas it improved the wetting properties and reduced the surface tension. Further, addition of TiO2 nanoparticles to PMMA resulted in increased hardness value of the tested material by 20%, 30% and 34% with addition of 1%, 2% and 3% TiO2 to pure PMMA, respectively and 11% to 31% increase in flexural modulus while the flexural strength increased linearly to 106.7 MPa with an overall increase of 95% from pure PMMA. Dynamic mechanical Analysis (DMA) indicated that storage modulus increased from 1500 MPa to 2120 MPa when the test frequency increased from 0.01 to 100 Hz, while the loss modulus increased from 120 MPa to 222 MPa as a function of test frequency. Similarly, the storage modules decreased significantly with increasing temperature (25 to 120 degrees C), from 1820 MPa to 300 MPa with a glass transition temperature of PMMA as 118.6 degrees C. The obtained parameters are encouraging to develop a composite PMMA using nano-metal oxide which do not chemically react but enhances the thermomechanical properties of an existing well investigated material.