Fabrication and physical properties of glass‐fiber‐reinforced thermoplastics for non‐metal‐clasp dentures

Abstract

Recently, non-metal-clasp dentures (NMCDs) made from thermoplastic resins such as polyamide, polyester, polycarbonate, and polypropylene have been used as removable partial dentures (RPDs). However, the use of such RPDs can seriously affect various tissues because of their low rigidity. In this study, we fabricated high-rigidity glass-fiber-reinforced thermoplastics (GFRTPs) for use in RPDs, and examined their physical properties such as apparent density, dynamic hardness, and flexural properties. GFRTPs made from E-glass fibers and polypropylene were fabricated using an injection-molding. The effects of the fiber content on the GFRTP properties were examined using glass-fiber contents of 0, 5, 10, 20, 30, 40, and 50 mass%. Commercially available denture base materials and NMCD materials were used as controls. The experimental densities of GFRTPs with various fiber contents agreed with the theoretical densities. Dynamic micro-indentation tests confirmed that the fiber content does not affect the GFRTP surface properties such as dynamic hardness and elastic modulus, because most of the reinforcing glass fibers are embedded in the polypropylene. The flexural strength increased from 55.8 to 217.6 MPa with increasing glass-fiber content from 0 to 50 mass%. The flexural modulus increased from 1.75 to 7.42 GPa with increasing glass-fiber content from 0 to 50 mass%, that is, the flexural strength and modulus of GFRTP with a fiber content of 50 mass% were 3.9 and 4.2 times, respectively, those of unreinforced polypropylene. These results suggest that fiber reinforcement has beneficial effects, and GFRTPs can be used in NMCDs because their physical properties are better than those of controls. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2254-2260, 2017.

Investigation of Impact Strength, Water Sorption and Cytotoxicity of Denture Base Resin Reinforced with Polypropylene Fiber: In Vitro Study

“…In accordance with the present study, Movade et al 4 found that 2% PPF group of specimens exhibited improved flexural strength values and they also presented that PPF groups of specimens had higher toughness values than glass fiber and polyethylene fiber groups of specimens. Similarly, Nagakura et al 16 suggested that glass fiber and PPF reinforcements have beneficial effect on the physical properties of denture base resin.…”

Evaluation of Resin Clasps with Different Design by Retentive Force

“…RPDs with resin clasps have superior esthetic performance to metal clasps and high elasticity to allow the same degree of retentive force as metal clasps (1)(2)(3)(4). RPDs with resin clasps are fabricated with thermoplastic denture base resin, the bending properties of which influence the retentive force, fitness, and transmission of stress to the abutment teeth (5)(6)(7)(8). For retentive force, past studies show that 5-10 N per tooth is required for the retention device of an RPD with wire clasps (9,10).…”

Elastic dental prostheses – alternative solutions for patients using acrylic prostheses: Literature review

“…The content of >50% of fibers in the mass base significantly influences the above-mentioned characteristics. 22 The presence of <10% of fibers in the denture composition does not change the physical properties. However, besides glass fibers content, their diameter is very important as well.…”

“…1,4,10,17,20 Some disadvantages of thermoplastic materials may be reduced by the introduction of glass fibers. 22 Glass fibers increase the strength of elastic materials, improve their bending strength and resistance to congelation. The content of >50% of fibers in the mass base significantly influences the above-mentioned characteristics.…”

“…Acrylic polymers dentures reinforced with glass fibers prove stronger than prostheses devoid of them. 22 Sometimes, unfavorable esthetic effects occur: nylon pellots visually shorten dental crowns and acetal clasps unnaturally thicken teeth.…”