An experimental investigation of HA/AL2O3 nanoparticles on mechanical properties of restoration materials

Abstract

Nano composite materials based on polymers are widely used in restoration martials like dental. Poly methyl methacrylate (PMMA) is one of the most used polymers as dental material. PMMA has disadvantages such as low flexural strength properties and impact strength. In this paper, the influences of additive aluminum oxide and hydroxyapatite nanoparticles on the mechanical and strength properties of PMMA (including flexural strength, impact strength, surface hardness and shrinkage behavior) is studied experimentally. For this purpose, nine standard mechanical testing samples of pure PMMA, PMMA/5HA and PMMA/10HA with various amounts of Nano aluminum oxide (3,6,8 wt.%) were prepared. The results showed that the mechanical properties of hybrid Nano-composites were significantly improved in comparison with the pure samples in a way that optimal Nano-composite with convenience flexural properties and impact strength is obtained. Moreover, the use of nanoparticles results in shrinkage reduction of hybrid Nano-composites in comparison with pure PMMA.

Effects of Filler Size on the Mechanical Properties of Polymer-filled Dental Composites: A Review of Recent Developments

“…96 Dental composites reinforced with nanoparticles displayed high hardness values. 60 Balos et al found that using SiO 2 with agglomerate size of 50 nm at very low loading (0.023 wt%) increased the hardness of PMMA denture base composites. 103 Incorporating ZrO 2 particles with average sizes of 5-15 nm in PMMA denture base at different loadings (1.5, 3, 5 and 7 wt%) significantly increased hardness at 7 wt%.…”

“…The hybrid nano-composites with 5 wt% and 10 wt% of HA and 6 wt% of Al 2 O 3 had the maximum flexural strength. 60 Two similar studies evaluated the effects of incorporating silver (Ag) particles (38 nm) into PMMA denture base. 61,62 Ag filler was incorporated at very low loadings (0.5 wt%) and (0.05 wt% and 0.2 wt%).…”

“…Decreased cross-section of the load-bearing matrix. 60,61,84,85 5. Changes in the modulus of elasticity of the matrix and crack propagation mode of the sample because of increased filler content.…”

PMMA denture base material enhancement: a review of fiber, filler, and nanofiller addition

“…116 In addition to improving surface roughness, 109 tensile strength, flexural modulus, 114 hardness, and thermal conductivity, 116 and radiopacity 111 as well as reducing shrinkage, 107,110 it has antibacterial properties without showing cytotoxicity. 108 A combination of fibers and other fillers also increased impact strength, hardness, 112 surface roughness, and thermal conductivity, 113 as well as compressive and fatigue strengths.…”

“…106 As listed in Table 3, the combination may be between different fibers, 7 different metal oxides and ceramics, [107][108][109][110][111] and fibers with metal oxides, 112,113 or ceramic materials. 48,[114][115][116] Hybrid fiber reinforcement significantly increased the flexural strength and toughness of reinforced acrylic resin.…”