Mechanical testing of toughened resin composite materials

The development of composite materials is increasingly widespread, which require superior mechanical properties. From many studies, it is found that the mechanical properties of composite materials are influenced by various factors, including the reinforcement content, both in the form of fibers and particle powder. However, those studies have not investigated the effect of the hardener weight fraction on the mechanical properties of resin composite materials. Even though its function as a hardener is likely to affect its mechanical properties, it might obtain the optimum composition of the reinforcing content and hardener fraction to get the specific mechanical properties. This study examines the effect of hardener weight fraction combined with fiber powder content on mechanical properties of EPR-174 epoxy resin matrix composite and determines the optimum of Them. The research was conducted by testing a sample of composite matrix resin material reinforced with coconut fiber powder. The Powder content was made in 3 levels, i.e.: 6%, 8%, and 10%. While the hardener fraction of resin was made in 3 levels, i.e.: 0.4, 0.5, and 0.6. The test results showed that pure resin had the lowest impact strength of 1.37 kJ/m2. The specimen with a fiber powder content of 6% has the highest impact strength i.e.: 4.92 kJ/m2. The hardener fraction of 0.5 has the highest impact strength i.e.: 4.55 kJ/m2. The fiber powder content of 8% produced the highest shear strength i.e.: 1.00 MPa. Meanwhile, the hardener fraction of 0.6 has the highest shear strength i.e.: 2.03 MPa.

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Comparison of Internal Adaptation of Bulk-fill and Increment-fill Resin Composite Materials

Operative Dentistry ◽

10.2341/17-269-l ◽

2019 ◽

Vol 44 (1) ◽

pp. E32-E44 ◽

Cited By ~ 6

Author(s):

FS Alqudaihi ◽

NB Cook ◽

KE Diefenderfer ◽

MC Bottino ◽

JA Platt

Keyword(s):

Composite Materials ◽

Resin Composite ◽

Aging Effect ◽

Measured Data ◽

Cavity Surface ◽

Restorative Material ◽

Tooth Structure ◽

Gap Measurement ◽

Internal Adaptation ◽

Fill Materials

SUMMARY Objectives: To evaluate 1) the internal adaptation of a light-activated incremental-fill and bulk-fill resin-based composite (RBC) materials by measuring the gap between the restorative material and the tooth structure and 2) the aging effect on internal adaptation. Methods and Materials: Seventy teeth with class I cavity preparations were randomly distributed into five groups; four groups were restored with bulk-fill RBCs: Tetric EvoCeram Bulk Fill (TEC), SonicFill (SF), QuiXX Posterior Restorative (QX), and X-tra fil (XF); the fifth group was restored with incremental-fill Filtek Supreme Ultra Universal Restorative (FSU). One-half of the specimens of each group were thermocycled. Each tooth was sectioned, digital images were recorded, and the dimensions of any existing gaps were measured. Data were analyzed using analysis of variance (α=0.05). Results: FSU had the smallest gap measurement values compared with the bulk-fill materials except QX and TEC (p≤0.008). FSU had the smallest sum of all gap category values compared with the bulk-fill materials, except QX (p≤0.021). The highest gap incidence and size values were found at the composite/adhesive interface. All aged groups had greater gap values in regard to the gap measurement and the sum of all gap categories compared with non-aged groups. Significance: The incrementally placed material FSU had the highest internal adaptation to the cavity surface, while the four bulk-fill materials showed varied results. Thermocycling influenced the existing gap area magnitudes. The findings suggest that the incremental-fill technique produces better internal adaptation than the bulk-fill technique.

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