Lanthanum glass infiltrated alumina/alumina composites for dental prosthetic applications

Abstract Lanthanum glass frits suitable for infiltration in pre-sintered alumina were developed in order to obtain innovative alumina–glass composites, which are promising materials for all-ceramic dental prosthetic restorations, such as single crowns and fixed partial dentures. Glass compositions belonging to the lanthanum-silicate-borate system were synthesized in order to reinforce and give an improved esthetic appearance to the pre-sintered Al 2 O 3 . Fifteen formulations, defined by using a mixture design approach, were melted and quenched in water at room temperature in order to obtain the frits. Those exhibiting the lower melting temperatures were tested for infiltration into Al 2 O 3 to obtain Al 2 O 3 /glass composites. The frits and the composites were characterized by X-Ray diffraction, differential thermal analyses, hot stage microscopy, colorimetry (Hunter color scale) and scanning electron microscopy. The mechanical properties of the composites, in terms of flexure strength, were evaluated using a three-point bending tests.