A crown is a type of dental restoration which completely caps or encircles a tooth or dental implant. Crowns are often needed when a large cavity threatens the ongoing health of a tooth. They are typically bonded to the tooth using a dental cement.
When we have decided to go ahead with a full crown restoration, we will set aside 2-3 appointments for the entire process. Although the majority of crowns are completed in two visits, there is sometimes a need for a third visit to ensure a proper fit.
The procedure begins with the removal of all decay in the tooth. Once we have removed the decay, we will take an impression of the tooth. This impression will be sent to our lab where your new restoration will be crafted. While this new tooth is created, we will provide you with a temporary restoration. Our temporary restorations will resemble your natural teeth so that you can continue with your daily life without worrying about a missing or incompatible tooth.
During your second visit to the office, we will proceed with the placement of your final restoration. This crown will be fitted comfortably into the mouth. We will make every effort to ensure that the new tooth feels exactly like one of your natural teeth. The final step in the process is to cement the crown into your mouth, leaving you with a beautifully restored smile.
Porcelain fused to metal (PFM) is a tooth colored crown with high strength. The metal core makes a PFM many times stronger than an all-ceramic crown. The metal core can be made of many different materials. In our office the metal core is only "high noble", which means almost all gold, over 96% or 23 carat (an additional 2.6% is platinum). We only use high noble metal due to the better-fit, extremely rare allergies and sensitivities, and better aesthetics. Tooth colored porcelain is baked on the outside of the gold. We only use the highest quality porcelains (a combination of beauty, biocompatibility, and strength). Because there is metal under the porcelain it blocks natural tooth translucency and is not as pretty (aesthetic) as an all-ceramic crown.
There are many different marginal configurations (the area where the crown meets the tooth) with a PFM. How well the margin of the crown fits affects the health of the gums and ultimately the longevity of the crown. We choose to do a porcelain butt margin, which is the most aesthetic (also the most challenging for the dentist and the laboratory technicians to perform well). A porcelain butt joint, when done well, is aesthetic, healthy for the gums, and durable. Back teeth receive as much as 10 times the force of front teeth. Therefore, PFMs are usually indicated on rear teeth that show very little when you smile.
An all-ceramic crown (or porcelain with ceramic substrate) is the most beautiful of all crowns. There is no metal so translucency is usually excellent (dependent on the type of materials used for an all ceramic crown). These crowns are usually indicated on front teeth or teeth that are highly visible. We use only the best materials (a combination of beauty, biocompatibility, and strength) for our all-ceramic crowns.
A full gold crown (FGC) is composed of gold and looks gold. We only use high noble metal for our gold crowns (about 72% or 18 carat gold, 3.5% platinum. High noble metal fits better and is much less likely to result in allergies or sensitivities. Full gold crowns are indicated on back teeth with low visibility and are performed rather than a PFM at patient's request. The primary benefit of a full gold crown is durability.
Other types of crowns include stainless steel (indicated for baby teeth that will be lost), noble metal (less gold and platinum) and base metal crowns (usually do not fit well, documented sensitivities and allergies, and a weaker bond to the overlying porcelain).