Crack Under Dental Crown

Crack Under Dental Crown

Is it possible to get a crack under dental crowns? Seattle cosmetic dentist Lance Timmerman DMD in Tukwila often places crowns over teeth that are cracked. Sometimes the cracks are painful, but often there are no symptoms.

Cracked Tooth Syndrome

When a crack is deep enough and one or more cusps flex, dentists call this “cracked tooth syndrome”. The pain will not go away without professional help. The first action is to polish, or reduce, the painful cusp so it does not flex when biting. If that relieves the pain, it may not get any worse and can be left alone. However, most of the time this simply delays placement of a crown. The primary cause of cracked tooth syndrome is large mercury amalgam fillings. Since they do not bond to the tooth, they make the teeth weaker and prone to fracture. Dentists know that amalgam fillings are “seeds for crowns” and anticipate crowning those teeth in the future.

Crowns Offer Circumferential Support

The main benefit of a crown over a cracked tooth is that all chewing forces are directed inward, while fillings allow teeth to flex outward. A crown covers a tooth all around it and should be rigid enough so that there is little to zero flexion. Bonding a crown to a tooth is also superior to cementing crowns due to the process of bonding. The etching, priming and bonding process disinfects the tooth structure ensuring that the tooth is “clean” and little to zero bacteria are trapped underneath. If bacteria reach the nerve of the tooth, root canal therapy may be needed.

Entire Crack Must Be Removed

When dealing with cracks, the entire crack must be taken out. Despite full coverage of the tooth and the circumferential support, if a crack remains underneath or beyond the margin (edge) of the crown it can continue to propagate. If the cement seal is broken flex can continue and elicit pain and eventually would lead to root canal therapy.