Denture Base Composites: Effect of Surface Modified Nano- and Micro-Particulates on Mechanical Properties of Polymethyl Methacrylate

Abstract

The most commonly used denture base material, polymethyl methacrylate, lacks ideal mechanical properties, which are reflected in its relatively high failure rate. Several methods have been explored to reinforce the material and reduce the cost of denture repair and replacement. In this study, various surface modified filler particles at different concentrations were dispersed in conventional and high-impact denture base materials and tested for their improvement in mechanical properties. Inorganic filler particles were coated with different silane coupling agents using an ultrasonic device. The particulates were dispersed in the resin and the composites polymerised through an innovative dual-cure technique. Charpy impact test, single-edge notch three-point bend fracture toughness test and Biaxial Flexural Strength (BFS) were performed on the specimens. The results showed that mechanical properties of the denture base resin can be improved by incorporating filler particles; however, the surface characteristics, quantity and level of dispersion of the particles play critical role in the mechanical behaviour of the composites. The results of this study are a promising step towards developing more fracture-resistant denture base materials.

Flexural Strength and Hardness of Filler-Reinforced PMMA Targeted for Denture Base Application

“…At the highest concentration, the E-glass fillers had increased the hardness of the composites by the highest amount followed by the ZrO 2 and then the TiO 2 . This result is in agreement with previous research, which has found that the addition of glass fibre [9,36], ZrO 2 [5,18] and TiO 2 [12,15] nanoparticles in PMMA at different concentrations statistically improved the surface hardness of PMMA denture bases. The increase in filler content enhanced the surface hardness up to the point at which the optimal level was achieved [22].…”

Mechanical properties and surface roughness of chitosan reinforced heat polymerized denture base resin

“…The reduced interactive contact points between chitosan and heat polymerized denture base resin in higher concentrations lead to poor adhesion and easy detachment from the resin matrix leading to voids and reduce the mechanical properties of the newer composite material. Asar et al [11], Nejatian T et al [40], Shakeri et al [41] observed the findings of the reduced interactive contact points in higher concentrations of different composite materials.…”

Prosthodontic Applications of Polymethyl Methacrylate (PMMA): An Update

“…For instance, PMMA absorbs water, which may compromise its physical and mechanical properties while in use [ 63 , 64 ] and make it vulnerable to failure under cyclic loading [ 65 ]. Currently, a number of researchers are focused on mechanical reinforcement [ 30 , 38 , 51 , 53 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ] and chemical modification [ 53 , 75 , 76 ] of PMMA to overcome its drawbacks and improve its properties, which have been reviewed in this article. In order to better understand and interpret these recent modifications, it is important to understand the chemistry, types, and properties of PMMA materials.…”

“…The PMMA-based materials should have certain desired properties depending on the biological application. Accordingly, PMMA materials have been extensively modified and explored in relation to various chemical [ 77 , 99 ], biological [ 77 , 100 , 101 , 102 ], physical [ 70 , 77 , 103 ], and mechanical properties [ 66 , 68 , 70 , 100 , 103 , 104 , 105 ]. Primarily, it is important to understand the ideal or desired properties of PMMA materials for denture base applications ( Figure 3 ).…”

“… Various representative examples of PMMA modifications and associated outcomes: ( a ) randomly distributed filler particles allowing crack propagation; ( b ) uniformly dispersed particles that enhance fracture toughness through crack diversion [ 66 ]; ( c ) impregnation with ZrO 2 resulted in increased Vickers hardness values [ 51 ] and ( d ) flexural properties [ 30 ]; ( e ) silica nanoparticle surface modification using trietoxyvinylsilane and chemical bonding to MMA to enhance the fracture toughness ( f ) of modified PMMA (from [ 240 ] with permission), PMMA (control), PMMA reinforced with silica (SiO 2 ) nanoparticles measuring ~12 nm (PMMA-SIL), and PMMA containing trietoxyvinylsilane-modified SiO 2 nanoparticles (PMMA T-SIL); ( g ) antimicrobial functionalization of PMMA by adding zinc oxide, potassium sorbate (PS), and sodium metabisulfite (SM) (from [ 241 ] with permission) showed no remarkable effects on L929 cell viability ( h ), however resulted in a significant antimicrobial action against bacteria and Candida albicans ( I ). …”