Dental Crown Definition
A dental crown or “cap” is a non-removable shell that covers the entire outer surface of a tooth. Crowns can be made of tooth-coloured porcelain or gold and are utilized to reinforce teeth or to improve their appearance. Patients have crowns placed to strengthen teeth compromised by:
- Cracks or fractures
- Large fillings
- Large or deep cavities
- Previous root canal therapy
A crown prevents future damage to a tooth and limits the growth or extension of cracks through the tooth. Root canal treatment leaves a tooth more brittle and susceptible to fracture and so a crown prevents unrestorable cracking and tooth loss.
A dental crown may also be placed for esthetic reasons to improve the appearance of teeth that are:
- Misshapen or mispositioned
- Stained severely
- Discoloured following root canal treatment
Crowns provide a smooth and uniform tooth-coloured surface to correct the colour and shape defects that are present. They can be designed to match the exact colour of neighboring teeth. Your crown will be made to have a shape that fits your smile perfectly.
Dental Crown Types
Dental crowns can be made from a variety of materials. These materials vary in strength, esthetic appeal, and the degree to which they wear down enamel on opposing teeth. Here is a list of some common dental crown materials along with their pros and cons:
- Gold/Metal: Gold or metal alloy crowns are durable and kind to opposing teeth. Gold and metal crowns do not fracture or break and they enjoy wonderful longevity. These crowns require that less of your tooth is shaved or prepared to accommodate fit. Their lone drawback is that they are not tooth-coloured and provide poor esthetics. Consider a gold or metal alloy crown on non-visible upper molar teeth.
- Porcelain-fused-to-Metal (PFM): PFM crowns have an outer porcelain layer for high esthetic appeal and an inner metal alloy layer for strength. Unlike gold or metal alloy crowns, the porcelain on a PFM crown can chip and fracture, although this happens rarely. These crowns require more tooth shaving or reduction compared to metal crowns. They are also abrasive against opposing tooth enamel and can cause accelerated tooth wear, especially in patients who grind their teeth. PFM crowns provide a nice balance between durability and esthetics. Consider a PFM crown on molar and premolar teeth that are minimally visible during smiling.
- Full Porcelain (E-Max & Empress): E-Max crowns are made of lithium disilicate and Empress crowns are made of ceramic glass. Both types of crowns are highly esthetic. E-Max is more durable compared to Empress, but both are weaker than Gold, PFM and Zirconia crowns. Both materials offer reasonable longevity but are more prone to fracture. Additionally, both types of crown are abrasive to opposing tooth enamel. Consider E-max crowns on premolars and canines in esthetic zones and Empress crowns on upper front teeth.
- Zirconia: These crowns are made entirely of Zirconium. They are extremely strong and durable with good longevity. They cause less wear of opposing enamel compared to full porcelain and PFM crowns. Zirconia crowns are tooth-coloured (but not very translucent) so they are a reasonable esthetic choice for molar and premolar teeth.
What is involved in having my crown made?
Dental Crown Procedure
First, your tooth is prepared by removing any decayed or weakened portions. During this preparation, your tooth is shaped so that the crown can fit properly. We then take a highly accurate impression to capture the shape of the prepared tooth. Next, we place a temporary crown on your tooth to protect it until your second appointment. At your second appointment, the temporary crown is removed, and the permanent crown is seated for a “try-in”. The try-in allows me to ensure that:
- Your bite is comfortable
- Your new crown is sealed properly to your tooth
- You approve of both the shape and colour or “shade” of the crown
Once we are satisfied with the crown and you approve the colour and shape, we can bond the crown to the tooth. You will be instructed to avoid heavy chewing on the new crown for 72 hours. You will also be advised to avoid flossing around the crown for 72 hours.
If you have broken or cracked a tooth or are experiencing sharp biting pain, you may benefit from the placement of a dental crown. Please contact us to book a free consult appointment with Dr. Kyle Hornby.