When a tooth has decay, a filling is a technique that can reestablish the normal function and shape of the tooth. Materials used for fillings include gold, porcelain, a composite resin and an amalgam. If a filling can no longer salvage a tooth because the decay is too invasive, then a crown, also known as cap, is used. Cracked teeth are held together by crowns as well. Crowns are also utilized when a tooth is discolored or misshapen. Crowns are fit on top of the metal parts of root canal implants or whatever remains of the patient’s original tooth. Dental bridges are another way crowns are helpful. They anchor either side of a dental bridge that is meant to fill a gap made by a missing tooth. Here are a few different types.
Gold is one of the best materials for a crown because it is long lasting and durable, however it is easier to see in the mouth which deters some patients from choosing it.
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| Gold crown |
Porcelain fused to metal (PFM) crowns are aesthetically pleasing, long-lasting, accommodate the shape of the tooth well and are inexpensive. Disadvantages to PFM crowns include the dark line that appears where the crown meets the tooth near the gum line and more of the original tooth needs to be removed to fit the crown.
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| PFM crowns |
All-porcelain or all ceramic crowns do not show a dark line, match other teeth extremely well, are non-allergenic and can be performed in one appointment. Though, these crowns are fragile, cause teeth sensitivity, tricky to fit, need more of the original tooth reduced and are more expensive than PFM crowns.
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| All-porcelain crowns |
Zirconia crowns resemble natural teeth well, rarely are rejected by the mouth, are fairly durable and do not need as much of the original tooth removed to fit.
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| Zirconia crowns |
Lithium disilicate crowns have low fracture rates, resemble natural teeth well and are easily shaped.
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| Lithium disilicate crowns |
Very good description of the different types!
ReplyDeleteThis sounds really interesting! I know you might talk about this in later posts but why might one type of crown be used over another? Does it have anything to do with the condition of the tooth decay?
ReplyDeleteGreat question! It can depend on a lot of different things like where the problem tooth is, how much the patient wants to pay and how much of the original tooth can be salvaged. For example it is uncommon for someone to get a gold crown on one of their incisors, front teeth, because it would not be esthetically pleasing so they might choose porcelain, zirconia or lithium disilicate. However, if a crown is needed on a molar, strength is the main concern since the most force is applied on the teeth in the back of the mouth, so a gold crown is a plausible choice. To fit a crown you do need a certain amount of healthy tooth and once the threshold is passed and the decay reaches the nerve then the patient will need a root canal.
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