50 Years of All-Ceramic Restorations
The first all-ceramic restorations were made in the 1960s. They used feldspathic porcelain, a type of glass ceramic, on an alumina silicate core. The core was strong, but the surface was fragile. However, the main problem with these restorations was that they shrank during firing, which resulted in unpredictable fitting and sizing, so results weren’t as good.
To counter this problem, magnesium oxide was added to the veneers, which meant that they would fire up in the proper size, but they were even more brittle, resulting in a relatively high failure rate. These veneers were used in the 1980s, and they have caused some people to have a poor opinion of porcelain veneers to this day.
The strength problem was overcome for many porcelain veneers by adding a plastic that binds the ceramic, giving the veneers a toughness that helped them resist damage.
From Powders to Presses
The new plastic-glass ceramics had another problem: they could only be produced by sintering. Sintering is a process that uses tiny particles of material that are then fired. The powder then bonds together, creating a whole object. The bad news about sintering is that it’s unpredictable, though not in terms of size or shape. Instead, sintering can lead to tiny voids or flaws in the veneers that can, again, lead to early failure.
This problem was solved using hot press molding. Now the material is put under intense heat and pressure to force it together without voids or flaws, greatly extending the lifetime of the porcelain veneers. In addition, we have many new ceramics that can be used to give additional strength when necessary for extreme bite situations.
Now, porcelain veneers can last 20 years or more for appropriate candidates who care for them properly.
If you want to talk about how porcelain veneers can help you smile, please contact Rice Dentistry in Irvine today for an appointment.