Imagine doing all your chewing on just a few teeth. This is what often happens when one or more teeth are worn, damaged, missing, or have been so heavily filled they can no longer function properly. Losing the support of the back teeth can also threaten the longevity of the front teeth and affect the health of other teeth. If teeth are not restored or replaced, this can progressively lead to bite changes, increased loading and wear, fracture of adjacent teeth, and even jaw, joint and muscle problems, not to mention aesthetic problems.
What are crowns and bridges?
A crown is a capping that fits over and around a tooth to protect it. Some tooth structure must be removed to make room for a crown but once it is cemented into position, it usually makes the tooth stronger and better looking than it was before. Crowns can also be adhered to implants. A bridge is where a tooth is missing and crowns on the adjacent teeth or implants (the ‘abutments’) are used to support the false tooth (the ‘pontic’) or teeth in between. Bridges restore aesthetics and stability after a tooth is lost.
When teeth are extensively restored, chipped, fractured or have compromised structural integrity, crowns can be used to restore teeth to optimal strength and aesthetics.
Reasons for having crowns
• Large, worn, fractured or defective fillings. Crowns can work where there is not enough tooth structure to support a normal filling. Once a tooth is 70 percent filled, it usually needs a crown.
• Fractured teeth. These may be caused by cracks, trauma, large unsupported fillings or habitual or accidental grinding and clenching. A crown can physically bind the cusps together preventing them from flexing under load.
• Endodontically treated teeth (teeth which have previously had a root canal therapy). If a tooth is not restored promptly, bacteria can contaminate the root canal therapy or cause recurrent decay. Molars and premolars that are endodontically treated are at risk of root fracture. An appropriate post and core system and crown can give endodontically treated teeth an excellent long-term prognosis.
• Missing teeth. Shifting and tipping of adjacent teeth can lead to changes in the jaw muscles, bones and joints, and make chewing and cleaning harder. acsm
Procedure preparation
• Removal of existing filling materials from the tooth
or teeth to be crowned
• Core or foundation build-up (composite resin)
• Crown preparation (removal of 1–1.5mm of tooth
structure from the top and sides of the tooth)
• Provisional crown or bridge construction
• Detailed impressions, bite registration
• Cementing of the provisional crown or bridge
Application process
• Removal of the provisional crown or bridge
• Cleaning of the tooth and isolation of the margin
• Cementation of the definitive crown or bridge
Dental Crown and Bridge - Dental Clinic Sydney Australia