Facile Preparation of TiO2/PMMA Nanocomposites with Enhanced Physio-Mechanical Properties for Dental Applications

Abstract

: Dental caries (or tooth decays) is a common oral disease in early childhood and adults of all ages, which is caused by long-term synergies of acid-producing bacteria and fermentable carbohydrates in the oral environment. The use of existing dental restorative materials (including silver amalgams, light-cured resins, and dental restorative composites) and dental restorative composites (including glass ionomers cement, despite being sealants, releasing fluoride and promoting remineralization) is commercially restricted due to their weak mechanical properties, poor abrasion resistance, low elastic modulus, improper shrinkage, less polishability, brittleness, poor wear resistance tensile strength, aesthetic etc. Therefore, the physical intercalation of nano-fillers with polymer resins in nanocomposites might be a better alternative, mainly due to the high surface area of nanofillers. The present work reports an economical hydro-solvo thermal combinatory method to prepare TiO 2 /PMMA nanocomposites with four distinct wt% (3%, 6%, 9% and 12%) of TiO 2 nanofillers. Their comparative structural, morphological, and functional group analysis was carried out with that of pure PMMA by XRD, AFM, and FTIR, respectively. The physio-mechanical properties of the nanocomposites (including Young modulus, ultimate tensile strength, break strength, hardness value (HV), flexural strength, water absorption, density tests and polymerization shrinkage) were measured using UTM, ASTM D790 standard, the Archimedes method and ASTM D570 standard, respectively. Significant enhancement in Young’s modulus, ultimate tensile strength, break strength, hardness value (HV), and flexural strength were recorded as compared with that of the pure PMMA, achieving the optimum values (1.23 times in Young’s modulus, 2.38 times in UTS, 2.37 times in break strength, and 2 times in HV) for the nanocomposite with 9% TiO 2 nanofiller. Similarly, significant reduction in water adsorption and polymerization shrinkage (linear decrease) was observed with increasing filler (TiO 2 ) contents, which reveals the dimensional stability of nanocomposites, favorable for dental implants, and this is attributed to the effective bonding of TiO 2 nanoparticles with the PMMA matrix. Such a tremendously enhanced physio-mechanical behavior of the TiO 2 /PMMA nanocomposite (particularly with 9 wt% TiO 2 nanofiller) reveals its promising potential for use as a dental restorative material.