abstract   statement of problem: hertzian indentation test has been proven to be an efficient and reliable alternative upon vickers hardness test. this method has been used to test dental ceramics, amalgams, glass ionomers and luting cements.there is limited published information about the load-bearing capacity of resin composites using hertizian indentation test. objectives: to investigate the...

statement  of  problem:  patients’ demand  for  tooth-colored  restoratives  in the posterior region is increasing. clinicians use universal nanohybrid resin composites for both anterior and posterior regions. there are few published reports comparing fracture toughness of nonohybrids and that of hybrid composite stored wet and dry. objectives: to investigate the fracture toughness of three nan...

STATEMENT OF PROBLEM Patients' demand for tooth-colored restoratives in the posterior region is increasing. Clinicians use universal nanohybrid resin composites for both anterior and posterior regions. There are few published reports comparing fracture toughness of nonohybrids and that of hybrid composite stored wet and dry. OBJECTIVES To investigate the fracture toughness of three nanohybrid...

BACKGROUND With the increase in demand for cosmetics and esthetics, resin composite restorations and all-ceramic restorations have become an important treatment alternative. Taking into consideration the large number of prosthodontic and adhesive resins currently available, the strength and durability of these materials needs to be evaluated. This laboratory study presents the shear bond streng...

Natural fibers are receiving considerable attention as substitutes for synthetic fiber reinforcements such as glass in polymer due to their low density, low cost, acceptable specific strength, reduced tool wear and respiratory irritation and renewable resources. The fibers are not uniformly distributed in the randomly oriented fiber reinforced hybrid composites due to manual lay-up and fibers a...

A combination of reinforcements at different levels can have a synergetic effect on the final properties of a composite. The aim of this work was to produce, evaluate, and compare the wet/dry cycling durability of the exposure of cement composites reinforced with conventional pulps at the micro-scale level, with nanofibrillated cellulose fibers at the nano-scale level, and with combinations of ...

We studied relaxation by hygroscopic expansion of the interfacial polymerization shear stress of bonded resin composites. In the experimental set-up, resin composite-cured-to-glass strips bent due to the polymerization shrinkage. The strips were stored wet or dry. The curvatures of the bent strips were recorded, by the scanning of the glass surfaces with a contact profilometer, periodically ove...