The purpose of this study was to assess the clinical application of metal-ceramic CAD/CAM crowns created by Co-Cr laser-sintering additive manufacturing, and we also evaluated the bond strength of opaque porcelain to Co-Cr frameworks. The bond strengths were 24.7 MPa/Vintage MP (VMP), 25.2 MPa/Heraceram NP (HNP), 23.8 MPa/Noritake AAA Opaque (NAO), 15.1 MPa/Noritake Super Porcelain EX-3 Universal Paste opaque (NSE), 27.2 MPa/Zeo Ce Light Super agent G-II (ZCG), 27.4 MPa/Zeo Ce Light Super Opaque (ZCO), and 27.2 MPa/GC Initial INmetalbond (GCI). From these results, the opaque porcelain for Co-Cr frameworks could be used in clinical practice as metal-ceramic CAD/CAM crowns.

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This study examined the effect of thermal cycling on the strength of temporary cements and the retention of crowns cemented on implant abutments with temporary cements for implants. Three commercially available temporary cements [Fuji TEMP (A), IP Temp Cement (B), and HY-BOND TEMPORARY CEMENT SOFT (C)] were examined. The specimens were subjected to thermal cycling (5±2℃, 55±2℃) for 3,000 or 5,000 cycles, and then the compressive strength and retention values were determined. The correlation between the compressive strength and retentive force of the cements was also examined. Cement A increased the retentive force after 3,000 cycles compared to that before thermal cycling (two-way ANOVA/Scheffè, p<0.05). The compressive strength significantly increased after thermal cycling for each cement (p<0.05). Glass ionomer cement A showed a significant positive correlation between the compressive strength and retentive force, but glass ionomer cement B and the polycarboxylate cement C did not.

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Calcium phosphates have been used safely and effectively as bioceramics for the past three decades in dental and medical practice. Of calcium phosphate bioceramics, hydroxyapatite (HA), β-tricalcium phosphate (β-TCP), and a mixture of these calcium phosphates (BCP) are extensively used as bone substitutes. When placed in bony defects, they do not inhibit, but rather promote new bone formation. The ability to cause new bone formation is defined as "osteoconduction", and bioceramics that show osteoconduction are employed as bone substitutes and scaffolds in bone tissue engineering. In this review, material properties of orthocalcium phosphates, including HA and carbonate-containing apatite (CA), are discussed, together with their preparation methods and sintering behaviors. Some emphasis has been placed on the reviewer's work.

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