Flexural Strength Of Fiber Reinforced Composites Research Articles

Effect of glass fiber non-dental’s length and position on the flexural strength of FRC

Glass fiber non-dental has a similar composition to E-glass fiber dental that commonly used as fiber reinforced composite (FRC) materials in resin bonded prosthesis. Fiber effectiveness can be determined by the length and the position. The aim of this study was to examine the effect of glass fiber non dental’s length and position on the flexural strength of FRC in resin bonded prosthesis. This study has been done used 36 FRC samples with beam shaped (15 mm x 2 mm x 2 mm). Fiber reinforced composite samples were consisted of 9 groups (a combination between length: 4 mm, 6 mm, and 12 mm and position: compression, neutral, tension zone). The flexural strength was tested by universal testing machine and statistically analyzed using two-way ANOVA (p<0.05). The result showed that the lowest (compression, 4 mm) and the highest (tension, 12 mm) flexural strength were 104.30 ± 13.90 MPa and 166.18 ± 8.59 MPa. The two-way ANOVA test showed that variation of position, length, and interaction between placement-length had a significant effect on the flexural strength (p<0.05). The conclusion of this study was fiber position on compression zone with 4 mm length had the lowest flexural strength. In addition, fiber position on tension zone with 12 mm length had the highest flexural strength.

Effect of Bombyx mori silk-fiber volume on flexural strength of fiber-reinforced composite

Dental glass fiber is one of dental synthetic fibers that are widely used in dentistry as a dental resin reinforcement, such as in dentin replacement material. The availability of glass fiber is limited in Indonesia because it must be imported and relatively expensive. Bombyx mori silk-fiber is one of the strongest natural fiber derived from silkworm cocoon processing. Silk-fiber is used in medical applications as a post-surgical sutures, scaffolds for tissue engineering and drug delivery. The purpose of this study was to evaluate the effect of Bombyx mori silk-fiber volume on the flexural strength of fiber-reinforced composite (FRC). We used Bombyx mori silk-fiber (Perhutani Pati, Central Java, Indonesia) and flowable composite (Charmfil flow, Denkist, Korea) in this study. The FRC samples were divided into 4 groups consisting of fiber volumes of 0%, 5%, 10% and 15% (n = 4). Tests of flexural strength were performed according to ISO 4049. The results were analyzed using one way ANOVA (p<0.05). The study showed that the means of the flexural strength (MPa) of Bombyx mori silk-fiber FRC for volume of 0%, 5%, 10% and 15% were 149.2 ± 5.5; 127.6 ± 3.8; 110.9 ± 3.5; 71.2 ± 4.2. One-way ANOVA test showed that the means of FRC flexural strength on the four groups’ silk-fiber Bombyx mori volumetric were significantly different (p<0.05). This study concluded that Bombyx mori silk-fiber volumetric influences the flexural strength of fiber- reinforced composite. An increase in Bombyx mori silk-fiber volume decreases the flexural strength of FRC because there is a small gap due to the weak interfacial bonds between dental flowable composite and Bombyx mori silk-silk-fiber.

The effect of silk concentration on the flexural strength of FRC as a Bone Graft

Bone fractures are mostly caused by trauma and disease. In the therapeutic process of bone healing which often meets some constraints, bone graft is mainly used to ensure that the healing process takes place. A fiber reinforced composite (FRC) is a popular bone graft material that is made to resemble bone properties. FRC is normally comprised of polymer matrix, hydroxyapatite filler, and fiber. Hydroxyapatite is a bioactive material widely used as a bone graft. Silk fiber is known as a reliable material to increase mechanical strength of the FRC. On this basis, this study aims to determine the effect of silk fiber concentration on the flexural strength of FRC. Fiber reinforced composite made of Bis-GMA/TEGDMA/ UDMA resin (CharmFil®, DenKist, Korea), hydroxyapatite (Bioceramic Laboratory, DTMI UGM) and silk fiber (Perhutani, Pati) were divided into three groups. Each group contained different silk fiber concentrations which were 1%, 5% and 10%. The flexural strength test was performed with 3-point bending test according to ISO 10477. The result showed that FRC with silk fiber 1%, 5% and 10% respectively had flexural strength of 61.21 ± 8.43 MPa, 62.97 ± 3.92 MPa and 85.01 ± 7.71 MPa. The result of one way ANAVA analysis showed that mean of FRCs flexural strength were significantly different between one treatment group to another. Thus, it is conclusive that silk fiber has a significant effect on FRCs flexural strength. The addition of 10% concentration of silk fiber is proven to increase FRCs flexural strength.

Effect of glass and polypropylene fibers in cementitious composites containing waste stone powder

In this study, stone powder as a waste material was used to fabricate cementitious composite samples. Neat (non-modified) cementitious samples were composed of gravel, cement, sand, water, and waste stone powder. Flexural and compressive strength tests showed that flexural and compressive strength could be improved by increasing waste stone powder weight percentage. In addition, the experimental results illustrated that samples containing waste stone powder present more flexural and compressive strength in comparison with those fabricated without waste stone powder at constant cement weight percentage. In the next step, polypropylene and glass fibers were used in specimens containing waste stone powder. Consequently, flexural strength of fiber-reinforced composites was modeled by modifying “Equal Cross-Section Theory.” The results show that fibers increase flexural strength of specimens; meanwhile, waste stone powder does not have a significant effect on compressive strength. In another step, it was tried to make cementitious composite samples containing perlite as a light aggregate. Cementitious composites containing waste stone powder and perlite presented more flexural and compressive strength compared to samples without waste stone powder.

Effect of fiber diameter on flexural properties of fiber-reinforced composites

Flexural strength (FS) is one of the most important properties of restorative dental materials which could be improved in fiber-reinforced composites (FRCs) by several methods including the incorporation of stronger reinforcing fibers. This study evaluates the influence of the glass fiber diameter on the FS and elastic modulus of FRCs at the same weight percentage. A mixture of 2,2-bis-[4-(methacryloxypropoxy)-phenyl]-propaneand triethyleneglycol dimethacrylate (60/40 by weight) was prepared as the matrix phase in which 0.5 wt. % camphorquinone and 0.5 wt. % N-N'-dimethylaminoethyl methacrylate were dissolved as photoinitiator system. Glass fibers with three different diameters (14, 19, and 26 μm) were impregnated with the matrix resin using a soft brush. The FRCs were inserted into a 2 × 2 × 25 mm3 mold and cured using a light curing unit with an intensity of ca. 600 mW/cm2 . The FS of the FRCs was measured in a three-point bending method. The elastic modulus was determined from the slope of the initial linear part of stress-strain curve. The fracture surface of the composites was observed using scanning electron microscopy to study the fiber-matrix interface. The results were analyzed and compared using one-way ANOVA and Tukey's post-hoc test. Although the FS increased as the diameter of fibers increased up to 19 μm (P < 0.05), no significant difference was observed between the composites containing fibers with diameters of 19 and 26 μm. The diameter of the fibers influences the mechanical properties of the FRCs.

Bond strength to enamel and flexural strength of fiber-reinforced composites

Bond strength to enamel and flexural strength of fiber-reinforced composites