The influence of fibre placement and position on the efficiency of reinforcement of fibre reinforced composite bridgework

Abstract

The effect of placement of ultra-high molecular weight polyethylene (UHMWPE) fibres on the flexural properties and fracture resistance of a direct dental composite was investigated. The UHMWPE fibres are increasingly being used for the reinforcement of laboratory fabricated resin composite crown and bridgework. The aim of this study was to assess the effect of a commonly used laboratory fabrication variable on the in vitro strength of beam shaped specimen simulating a three-unit fixed bridge. Four groups (10 specimens per group) of Herculite XRV were prepared for flexural modulus and strength testing after reinforcement with UHMWPE fibres. Two groups of control specimens were prepared without any fibre reinforcement. Half the specimen groups were stored in distilled water and the other groups were stored dry, both at 37 degrees C for 2 weeks before testing. The results of this study showed that placement of fibre at or slightly away from the tensile side improved the flexural properties of the composite in comparison with the unreinforced control specimen groups whilst the mode of failure differed according to fibre position. Scanning electron microscope (SEM) investigation revealed that placement of the fibre slightly away from the tensile side favoured crack development and propagation within the resin bridging the interfibre spaces in addition to debonding parallel to the direction of fibre placement. Laboratory fabrication variables may effect the strength of fibre reinforced bridgework significantly.

Fracture Strength of Direct Surface-retained Fixed Partial Dentures: Effect of Fiber Reinforcement versus the Use of Particulate Filler Composites Only

“…In this study, however, no statistically significant differences were obtained between the fracture strengths of E-glass and UHMWPE fibers. At this juncture, it should be highlighted that the mechanical properties of FRCs are influenced not only by the inherent material properties of the fibers and their polymer matrices, but also by a host of other factors -namely fiber surface treatment, quantity, direction, and position of fibers 13,14,19) . All of this information can be derived from bar-shaped specimens prepared according to ISO norms 13) .…”

“…Effective preimpregnation also allows the matrix to increase the surface wetting property of the fibers and helps to keep the fibers in close contact within a fiber bundle 12) . Furthermore, good impregnation of fibers with the surrounding monomer matrix is important since fiber reinforcement is successful only when the loading force could be transferred from the resin matrix to the fibers 13) . Pre-impregnated systems usually involve monomers like urethane dimethacrylate (UDMA), urethane tetramethacrylate (UTMA), bisphenol glycidylmethacrylate (Bis-GMA), or polymethyl methacrylate (PMMA) either already impregnated by the manufacturer or readily performed by the clinician.…”

Fiber-matrix integrity, micromorphology and flexural strength of glass fiber posts: Evaluation of the impact of rotary instruments

“…In contrast, the specimens in the current study that were sectioned with a carbide disk presented a more regular surface, showing that water irrigation may be sufficient to promote a more homogeneous surface and prevent the formation of burnt areas (Burns). Two-point 2) and three-point 16,[20][21][22] flexural strength test have been extensively used to assess the mechanical properties (hardness, tensile, flexural modulus) of fiber reinforced polymeric materials used in dentistry. Therefore, these evaluation methods provide data that can be compared to the data from other studies.…”

Pengaruh posisi dan fraksi volumetrik fiber polyethylene terhadap kekuatan fleksural fiber reinforced composite (The effect of position and volumetric fraction polyethylene fiber on the flexural strength of fiber reinforced composite)

“…Area gigi tiruan yang lemah berada pada sisi yang mengalami tekanan tarik, tekanan tarik akan berdampak pada pemanjangan dimensi gigi tiruan. 16 Sebagian besar fraktur terjadi oleh karena komponen tekanan tarik. 17 Aplikasi tekanan tarik akan menyebabkan molekul-molekul berupaya bertahan terhadap tarikan yang berakibat terpisahnya ikatan antar molekul yang memungkinkan terjadinya fraktur.…”

“…4 Distribusi tekanan memberi pengaruh yang signifikan terhadap kekuatan FRC, apabila distribusi tekanan lebih merata maka fraktur tidak mudah terjadi. 16 Penambahan jumlah fiber sebanyak 2 lembar akan meningkatkan kekuatan fleksural FRC dibandingkan FRC dengan jumlah 1 lembar fiber dan tanpa fiber. Desain jembatan dengan 2 lembar fiber mempunyai kekakuan yang tertinggi dibandingkan desain jembatan dengan 1 lembar dan tanpa fiber.…”