Comparative Effect of Glass Fiber and Nano‐Filler Addition on Denture Repair Strength

Abstract

Purpose To evaluate and compare the effects of glass fiber (GF), Zirconium oxide nanoparticles (nano‐ZrO2), and silicon dioxide nanoparticles (nano‐SiO2) addition on the flexural strength and impact strength of repaired denture base material. Materials and Methods Heat‐polymerized acrylic resin specimens were fabricated. All specimens were sectioned centrally and beveled creating 2.5 mm repair gap except for 10 controls. Specimen grouping (n = 10/group) was done according to filler concentration of 0%, 0.25%, 0.5%, and 0.75% of auto‐polymerized acrylic powder. Modified resin was mixed, packed in the repair gap, polymerized, finished and polished. Three‐point bending test and Charpy type impact testing were done. Data were analyzed using one‐way‐ANOVA and Post‐Hoc Tukey test (α = 0.05). Results All additives significantly increased flexural strength and impact strength (p < 0.05). Within the modified subgroups, no significant differences were found for GF. Significant increase for nano‐ZrO2 and significant decrease for nano‐SiO2 as the concentration of additive increased were noted for both flexural strength and impact strength. Highest flexural strength was found with 0.75%‐nano‐ZrO2 (69.59 ± 2.52MPa) and the lowest was found with 0.75%‐nano‐SiO2 (53.82 ± 3.10MPa). The 0.25%‐nano‐SiO2 showed the highest impact strength value (2.54 ± 0.21 kJ/m2) while the lowest impact strength value was seen with 0.75%‐nano‐SiO2 (1.54 ± 0.17 kJ/m2). Conclusion Nano‐filler effect was concentration dependent and its addition to repair resin increased the flexural and impact strengths. The incorporation of 0.75%‐ZrO2 or 0.25%‐SiO2 into repair resin proved to be a promising technique to enhance repair strength and avoid repeated fractures.

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

“…Various factors were of significance during the process of incorporating filler into PMMA: The distribution of the polymer matrix, the shape and size of the filler, and the level of bonding between the filler and the matrix [ 10 , 26 , 41 ]. The filler needs to be small enough to produce a homogenous mixtures and can penetrate between the linear macromolecule chains, thereby restricting their movement [ 9 , 42 ]. Previous studies have concluded that the percentage filler should be sufficiently low to ensure the fillers are embedded in the resin [ 15 , 18 ].…”

“…The addition of 1.5 wt.% and 5 wt.% ZrO 2 into PMMA also increased the flexural strength of the material; however, the difference was not statistically significant. Thus our proposal was that homogenized blending of fillers into a PMMA matrix might improve the strength of the material [ 11 , 42 ]. However, we observed that the higher ratios of particles led to appearances of clustering, which form spaces.…”

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.…”

Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

“…The nonuniformity of both components when mixing can lead to a decrease in material strength and bacterial invasion, which can decrease biocompatibility [ 6 ]. To overcome the shortcomings of PMMA, such as the inadequate mechanical properties and bacterial invasion, the material composition has been changed, and various reinforcing materials have been added [ 7 , 8 ]. However, because the conventional complete denture manufacturing method is complicated, the degree of perfection of the denture may differ depending on the experience and skill of the dentist or dental technician.…”