Revolutionary History of All Porcelain TeethTime：2021-06-09Views：1449
Due to the transparency and refractive index of dental cast glass ceramics close to that of enamel, the appearance color of the full crown made of it is almost the same as that of natural teeth, achieving the best aesthetic effect.
Ceramics have excellent light transmission and light reflection properties, can reproduce the translucent depth and color depth of natural teeth, have good biocompatibility, do not degrade in the oral environment, polished and glazed porcelain surfaces are smooth, and due to their The significant advantages such as wear resistance similar to natural teeth, so it is very popular with clinicians.
As early as 1886, ceramics began to be used in oral restoration. Because of the many advantages mentioned above, ceramics have always been an important material for dental crowns and bridges. However, its application is limited due to its shortcomings such as low radial bending strength, high sintering strength, and poor edge compatibility with prepared teeth. Since then, people have been trying to find an all-ceramic restoration material that is both beautiful, high-strength, and convenient for clinical production. For more than 100 years, improving the strength of dental ceramics has always been the goal pursued by clinical dentists and ceramicists.
In 1903, the Michigan dentist Charles Land used platinum foil technology to use feldspar porcelain to fire the first porcelain crown with a color similar to that of natural teeth on a refractory model. Because the radial bending strength of the porcelain is only 60~70Mpa, the porcelain crown is easy to be broken and the application effect is not good.
In 1965, Mc Lean reported the aluminum-ceramic crown, the inner core of which was made of high-alumina porcelain containing 50% Al2O3, and the strength was nearly 50% higher than that of the porcelain crown, thus introducing the technology of the aluminum-ceramic crown. In 1973, Southan et al. invented a porcelain crown called Hi-Ceram. For the first time, the technology of directly grilling aluminum porcelain on the refractory mold was used, which overcomes the difficulty of grilling on platinum foil and improves the porcelain performance. The strength and fit of the crown. In 1983, Sozio et al. invented the Cerestore aluminum-ceramic crown, which uses an aluminum-ceramic material with minimal shrinkage (containing 85% Al2O3), uses the lost wax method to form a casting cavity, softens the aluminum-ceramic billet, and casts it to form an inner crown. After being grilled at high temperature, the volume expands to compensate for shrinkage, and then the surface is conventionally made of porcelain. Dicor casting ceramics launched by Corning and Dentsply in 1984 have better mechanical properties after microcrystallization, but the color modified by surface coloring and cement adjustment is still not ideal, and it is time-consuming and complicated. In 1986, the IPS Empress castable glass-ceramic jointly developed by Ivoclar and the Department of Crown and Bridge of the University of Zurich came out. The cavity is formed to form a crown, and the surface is then glazed and colored. IPS Empress porcelain has beautiful appearance, good translucency, refractive index similar to that of enamel, good edge adhesion and fracture resistance, and its radial bending strength can reach 160~182Mpa. Similar wear resistance. In September 1988, at the 7th International Porcelain Symposium held in Paris, Sadoun of France proposed an all-ceramic crown and bridge restoration technology called Slipt-Casting, which was later improved by German Vita Company. , launched under the trade name In-Ceram. Slurry-coated aluminum-ceramic crowns have high radial bending strength, which is almost 3 to 4 times higher than some cast ceramics of all-ceramic restoration systems. It can not only be used for the production of single crowns for anterior teeth, but also for the production of three-unit bridges for anterior teeth. , It also has the advantages of good edge suitability and good light transmission.