A Technique for Evaluating Dental Adhesives
A method is proposed for evaluating the strength of an adhesive joint. It is basically a fracture mechanics approach which recognizes that the strength of a joint depends on adhesive thickness, elastic properties of adhesive and teeth, joint geometry, sizes of flaws, and other factors. The "blister" technique is proposed as a useful means of quantitatively determining the quality of an adhesive joint.
Comparison of the Strength of Barnacle and Commercial Dental Cements
The strength of barnacle cement was compared with commercial dental polymeric restorative materials and cements by use of a fracture mechanics approach in conjunction with a blister technique. Barnacles were "grown" on various surfaces and the adhesive fracture energy of the cements was determined. These values were compared quantitatively with available commercial materials. On a wet surface, barnacle cement was favored.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.