Dental crowns are very important restorations. They are used to save badly damaged teeth in many situations. You may have a chipped or cracked tooth that’s vulnerable to further damage. You may have significant decay that’s weakened the tooth. Or your tooth may even have had an infection and needed a root canal treatment. In all these cases, a dental crown can be used to save your tooth for years, even decades of further use.
But in the past it couldn’t do this and still be attractive. If you were getting crowns to repair damaged teeth, there was a good chance that those crowns would have to be unattractive metal crowns. But now new materials allow us to make dental crowns that are both beautiful and strong enough for any repair.
Traditional Dental Materials
In the past, dentists had to make crowns with materials that were hundreds (if not thousands) of years old. This meant that they had to choose between metals and ceramics. Metal crowns could withstand all the force of biting and chewing, even in the back of the mouth where these forces are greatest. They were made of gold or sometimes noble metal alloys. (Stainless steel crowns were also available, but many people had reactions to them, similar to costume jewelry.)
The other option was porcelain crowns. Like the earliest veneers, these were literally porcelain, the same material that’s used in plates and figurines. Beautiful but fragile. Actually, porcelain is relatively strong for a ceramic, but when it’s reduced down to a fraction of a millimeter as is necessary for a dental crown, it’s just not strong enough.
Innovations allowed for stronger attractive crowns, made from sintered glass or composite plastic/ceramic materials. Although these were stronger, they still weren’t strong enough to withstand the forces at your molars. And they had other problems. Sometimes they didn’t fit properly, or they developed discolouration over time. They often weren’t worth the tradeoff for the extra strength.
The Beauty of Modern Ceramics
Then came the millennial materials. Around the year 2000, several types of new, advanced ceramics were adapted for use in dental crowns and other restorations. The first was lithium disilicate, which is amazingly beautiful. It looks so much like natural tooth material that when done properly even dentists have to inspect closely to tell the difference.
But this material is not just another pretty face: it’s a beast! This beautiful ceramic is more than twice as strong as tooth enamel. When this material was introduced, we no longer had to tell people to be careful with their dental crowns. Anything that’s appropriate for your natural teeth is appropriate for these crowns.
But these crowns aren’t always appropriate for the back of the mouth. Wait, you might say, how can they be stronger than the tooth, but not stand up where natural teeth are? Natural teeth are really amazing. They’re designed to break but not fail. When put under too much stress, the outer layer of the tooth will crack and the internal layers of the tooth will flex. This causes long-term damage, but it doesn’t (usually) lead to catastrophic failure. Ceramic crowns can’t do that.
But that’s okay, because now we have an even stronger alternative: zirconia. Zirconia is about four times stronger than lithium disilicate. That’s not only ten times stronger than your tooth enamel, it’s twice as strong as the titanium used in dental implants! Zirconia crowns are strong enough to withstand anything a natural tooth could. If you are cracking zirconia crowns in your mouth, you have much bigger problems than a dental crown!
Zirconia crowns don’t look quite as attractive as the lithium disilicate. But they look good for back teeth.
Strong and Beautiful Smiles
In the past, getting a dental crown meant choosing between strength and beauty. But today, you don’t have to make that choice between a durable restoration and a beautiful one. Even if you have bruxism (teeth clenching and grinding) or TMJ, you can still keep your beautiful smile with dental crowns.