Design and processing of ceramic-based analogs to the dental crown

The structure and properties of the crown of a human tooth were used as a model for the design and processing of dental restorative materials. The synthetic analog to the crown was composed of a dentin-like material (alumina-glass or alumina-polymer composite) and an enamel-like material (calcium phosphate-based coating). The dentin composites had high strength (~450 MPa and ~160 MPa for aluminaglass and alumina-PMMA composites, respectively) and good fracture toughness (~3.8 MPa m ^{1 2} and ~3.3 MPa m ^{1 2} for alumina-glass and alumina-PMMA composites, respectively). The calcium phosphate-based enamel region was roughly 80 μm thick, dense and fully crystalline. Bonding between the dentin and enamel in the analog was accomplished in a manner similar to the dentinoenamel junction in the natural tooth. A region of interpentrating phases from the synthetic dentin and enamel coating was created and excellent bonding was achieved using a eutectic melt in the CaO-Al₂O₃-SiO₂ system.