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[Development of partially sintered alumina block for dental CAD/CAM and mechanical properties testing].

OBJECTIVE
It is a new way to fabricate all ceramic crowns by combining dental CAD/CAM with glass infiltration technology.


METHODS
A partially alumina sintered block made of a high purity, fine alumina powder was shaped by isostastic pressure and sintered at 1,400 degrees C. Its mechanical properties were tested and microstructure was observed by SEM.


RESULTS
The Vicker's hardness, three-point bending strength, fracture toughness of partially sintered alumina block were 1.65 MPa, 210 MPa, 1.90 MPam1/2 respectively. Micrographs of SEM indicated that partially sintered alumina contained the structure of continuous three-dimensional open pores through the neck growth and surface diffusion of the interparticles.


CONCLUSION
The partially sintered alumina block that developed in this way may be used to mill for CAD/CAM and fabricate the shrinkage-free all ceramic crown.