Dental crowns are an effective treatment for cosmetic purposes, such as to cover a discolored or poorly-shaped tooth, and functional purposes, such as to protect a weak tooth from fracturing. They are quite versatile in their uses, but what are they made of? Read on to find out.
Types of Dental Crowns
There are currently three main types of crowns, each made using different materials. The cast gold crown is considered to be the “oldest” dental crown in use. These crowns are made of a noble or high-noble gold alloy (mostly gold, platinum, and palladium, with a few other trace elements added to increase the strength and durability of the crown). Gold crowns in the past have been used when there is very little tooth structure present or when the point where the crown and tooth meet is below the gum line. This type of crown has become less popular in recent years due to the increasing price of gold as well as patient desires for a more cosmetically-pleasing result.
To meet demand, the porcelain-fused-to-metal (PFM) crown became more popular. This type of crown has a cast metal coping (similar to gold crowns) with porcelain layered over the top. Though this type of crown is more visually appealing than gold crowns, they require the tooth to be more aggressively shaped than other types of crowns and can darken over time.
In more recent years, ceramic crowns have gained popularity because of their strength, the accuracy in which they can be created, and their appearance. Most “modern” crowns now are made using solely ceramic. Ceramic crowns themselves are divided into two categories – zirconia and glass-ceramics. Both types are created digitally, milled with a highly-accurate mill, and then fired in a porcelain oven. This process creates a beautiful crown that looks comparable to a natural tooth, doesn’t stain the surrounding teeth and soft tissues, and that is still durable enough to withstand any chewing tasks it is needed for.