What happens under the crown
A crown closes off the prepared tooth stump like a cap and protects it from mechanical stress, temperature stimuli and bacteria. It is attached with a dental cement that acts either conventionally (glass ionomer, zinc phosphate) or adhesively (composite-based). When this connection fails, the prepared stump is exposed. This is rarely an emergency with pain, but always an indication for a timely appointment.
In most cases we see one of three situations on the stump:
Stump intact, crown intact. Most common finding. The cement was simply at the end of its lifetime, often after ten to fifteen years. We clean both surfaces mechanically and chemically, and reattach the crown with modern adhesive cement. One session, 45 minutes, then fully load-bearing.
Stump with secondary caries. Second most common finding. Bacteria have penetrated through a small leak under the crown and weakened the stump from inside. We remove the carious substance, build up the stump if necessary with composite or a post, and re-cement the crown. Sometimes the old crown fits, sometimes a new fabrication is needed. With the Resident CEREC procedure we do this in one session.
Stump fracture. Rare but relevant. The stump has broken under the crown, often at the root surface or below. Here restoration depends on whether the fracture course allows a post build-up or requires extraction. With extraction, restoration with an implant or bridge follows after a healing phase. More on the decision implant or bridge.
When it still becomes urgent
Even though a lost crown is usually not an acute emergency, there are constellations in which we should see you on the same day. These include all forms of pain on the stump, sensitivity to temperature or sweets that does not subside within 30 seconds, odor formation on the stump (indication of inflammation), and of course any fracture of the crown or stump.
If the crown sits on a front tooth, in addition to the medical aspect, the aesthetic aspect is also relevant. For the transitional phase until the appointment, we can discuss an immediate temporary option by phone.
Prevention
A properly fitted crown lasts 10 to 20 years with healthy oral hygiene, often longer. The most important factors for longevity are regular check-up and dental hygiene, avoidance of grinding and pressing (if necessary with night guard) and conscious avoidance of extremely hard foods or ice cubes.
If you frequently have problems with crowns or fillings, a fundamental bite analysis is useful. Sometimes the problems are not with the individual tooth, but with the entire bite position. Address this at the appointment.