When your molar is chipped, it's a good idea to cover it with a crown even if the damage isn't highly visible when you smile. A crown helps to protect the underlying tooth from decay, and it also helps stop it from being damaged further when you're chewing food. When placing a crown on a molar, dentists have used porcelain-fused-to-metal crowns for decades. PFM crowns are created by adhering porcelain to a metal backing that gives it added durability.
Recently, ceramic crowns like zirconia crowns have become more popular when performing restorations on molars. While they haven't been in use as long as PFM crowns, they can often be the better option when placing a crown on a molar. Zirconia crowns are a type of ceramic crown that's manufactured from zirconium dioxide. Since zirconium dioxide is so strong, there's no need to reinforce these crowns with a metal backing. Below, you'll find three reasons why zirconia crowns are often the best choice to protect a damaged molar.
1. Zirconia Offers Better Durability Than Porcelain
Your molars undergo quite a bit of force when you're biting down on food, and this typically makes zirconia crowns the better option when you're placing a crown on one of your molars. Zirconia is much more durable than porcelain. While the metal backing of a PFM crown helps to reinforce it, porcelain is a fairly brittle material. It's more susceptible to cracking or chipping while you're eating.
Zirconia crowns are less likely to suffer damage due to their superior durability. In fact, they're often recommended for people who frequently grind or clench their teeth during the night. This is a condition called bruxism, and it regularly places extreme force on the molars. Zirconia can withstand the nightly grinding and clenching, whereas PFM crowns may eventually crack because of the stress.
2. PFM Crowns May Damage Your Natural Teeth
Another advantage that zirconia crowns have over PFM crowns is that they're less likely to wear away the enamel on your natural teeth. The feldspathic porcelain used to create PFM crowns is slightly abrasive, so it can wear away the enamel on the tooth it makes contact with when you're chewing. If your enamel is worn away, your tooth becomes more susceptible to deep cavities and is likely to become sensitive.
Zirconia crowns are polished after they're made so that they don't have an abrasive edge, which prevents them from wearing away any enamel when they make contact with one of your natural teeth. This makes a zirconia crown a better choice for protecting your oral health.
3. PFM Crowns Can Reveal Their Metal Backing if Your Gums Recede
The base of a PFM crown contains a small ring of metal that is hidden underneath your gums when the PFM crown is placed. If your gums recede due to age or gum disease, this metal ring will become visible near your gum line. Zirconia crowns are a solid piece of zirconia, so there's no need to worry about any metal backing becoming visible.
Overall, zirconia crowns are often worth the extra expense when you're placing a crown on one of your molars. PFM crowns are more prone to chipping, and they can damage the enamel on your natural teeth. The durability of zirconia most often makes it the best choice to withstand the chewing and biting forces that your molars undergo while you're eating. If you have a chipped or damaged molar that needs a crown, contact a dentist in your area that has experience performing restorations with zirconia ceramic crowns.