Cap/Crown came loose - How to cement it back

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By Dr. David Leader

People like their dental crowns firmly attached to their teeth. When a crown becomes loose, dentists are not always available to replace them. In many cases, people can temporarily re-cement their loose crown just like a dentist. When a crown falls off a tooth, look inside the crown. If the crown is full to the brim with hard or soft material, the tooth may be broken. Look at the tooth in the mouth. If the tooth breaks even with the gum line, wait for the dentist's assistance. Be sure to consult a dentist if there is extreme pain or swelling.

If the crown is mostly hollow, that is a good sign. If the crown has a quarter to half inch post sticking out of it, that is good as well. In either case, that means that the cement that holds the crown onto the tooth probably gave way. Crowns like that are relatively easy to re-cement.

Gather the tools and materials necessary to re-cement the crown. First, find something to use for the cement. Many Pharmacies and grocery stores carry temporary filling material. A popular brand is Dentemp. Buy two or three doses of cement. The crown could loosen again or not go on correctly the first time. Denture adhesive or even sugar free chewing gum may work in a pinch. A paper clip is a handy tool to clean the old cement out of the crown. Get a toothpick and floss to clean away the excess cement. Find a countertop or vanity mirror; a countertop, magnifying mirror is better. A toothbrush rounds out the armamentarium.

First, clean off the tooth with the toothbrush and floss. Rinse away loose particles of cement or food. Then, clean out the crown. Open the paperclip, and use it to scrape any loose cement out of the crown. For crowns that have posts, scrap the cement off the post. If the post falls off, or becomes very loose, leave this job to the dentist. Do not worry if the tooth is somewhat sensitive to cold water, air, or touch. Sensitivity is normal for teeth that have not had root canal treatment.

Now that the tooth and crown are as clean as possible, try to fit the crown to the tooth without cement. The crown should seat securely. The opposing teeth should be able to bite together without feeling that the crown is higher than the other teeth. If the crown does not feel right, clean the crown and the tooth again. Try seating the crown different ways. When it does not fit correctly one way, try turning it around. It may have to slide in from the cheek side or from the tongue. Be patient. This step is critical. Sometimes, even dentists have trouble at this point. Do not re-cement the crown if it does not feel right without cement.

The next step is important, as well. Look in the mirror. Take the crown out, and replace it a few times. Get a good feel for how the crown slides onto or how the post slides into the tooth. Check each time that the teeth bite together normally. See how the crown lines up with the teeth around it.

Now, carefully read the directions for the temporary cement. Some are ready to use. Some cement requires mixing a liquid and powder. There are cements that can temporarily fill teeth or cement crowns. Use the correct set of instructions for the job.

Clear a flat workspace. Dry the tooth and the crown with cotton gauze or tissue. Do not leave bits of paper or tissue on either. Mix the cement. Fill the crown or apply cement to the post and the underside of the crown. Squeeze the crown onto the tooth as in the practice step. Bite together. After a minute or two (look at the directions for the cement), clean the excess cement from the edge of the crown on the tongue and cheek sides with the toothpick. Then, use floss to clean between the teeth. Do not pull the floss out from between the teeth by both ends. Release one end and pull the floss through while biting. Use the toothbrush and toothpick to clean the cement off the crown and the other teeth.

Now that the crown is back where it belongs, it may be fine for days or even weeks. Carry the tool kit around until the dentist can do a more permanent job.

A final note: some people find it easier if a very close friend or relative does this for them. Additionally, remember not to swallow the crown, although it will pass through without incident if you do.

Please see Dental First Aid for a list of available temporary cap/crown adhesives

Dr. David Leader is the Chairman of the Health Advisory Committee of the Lynnfield Schools, a member of the Professional Advisory Committee of Tri-CAP Head Start, and is a member of the Mass Dental Society Council on Dental Care and Benefits Programs.