Dental Cement: How It Holds Crowns in Place

Updated October 2026

Dental cement is the material that permanently attaches a crown, bridge, or inlay to your natural tooth or implant. It fills the tiny gap between the restoration and the tooth, locks the two together, and seals the edges so bacteria cannot leak underneath. With good care and the right cement, many crowns last 10 years or more.

What Is Dental Cement Made Of?

Most dental cements start as a powder and a liquid (or two pastes) that are mixed right before use. The mixture flows easily at first so the crown can seat fully, then sets hard within minutes. Zinc phosphate cement, one of the earliest permanent cements, has been used since the late 1800s and is still available today, but modern offices have several newer options.

Types of Dental Cement Used for Crowns

• Resin cements: Plastic-based cements that bond to both the tooth and the crown. They are the strongest option and are often used for all-ceramic and zirconia crowns, veneers, and onlays.
• Glass ionomer and resin-modified glass ionomer: Popular for metal-ceramic and zirconia crowns. They release small amounts of fluoride, which can help protect the edge of the tooth from decay.
• Zinc phosphate: A traditional cement with a long track record, used mainly for metal and metal-ceramic crowns.
• Temporary cements: Weaker cements, such as zinc oxide eugenol, designed to hold a temporary crown for a few weeks and come off easily when the permanent crown is ready.

Your dentist chooses the cement based on the crown material, how much natural tooth remains, whether the crown sits on an implant, and how easy the area is to keep dry during placement.

How a Crown Is Cemented

At Mercer Island Dental, cementing a crown usually happens at the final visit:

1. The temporary crown is removed and the tooth is cleaned.
2. Dr. Shiotsu checks the fit, bite, and color of the permanent crown before cementing it.
3. The tooth surface is prepared so the cement bonds well. For resin cements this may include a conditioning step.
4. Cement is placed inside the crown, the crown is seated, and any excess is removed from around the gumline.
5. The bite is checked again after the cement sets.

Learn more about the full process on our dental crowns page.

How Long Does Dental Cement Last?

Permanent cement is designed to last as long as the crown. When a crown fails, the cause is usually something else: new decay at the edge of the crown, a cracked tooth underneath, grinding, or chewing very hard or sticky foods. Regular checkups and cleanings let us spot a failing seal early, before the crown comes loose.

What to Do if Your Crown Falls Off

• Keep the crown in a clean, safe container and bring it to your appointment. It can often be cleaned and recemented.
• Call your dentist as soon as possible. An exposed tooth can be sensitive and is more likely to break or decay.
• Over-the-counter temporary dental cement from a pharmacy can hold a crown in place for a day or two if you cannot be seen right away. Follow the package directions and make sure the crown seats fully.
• Never use super glue or household adhesives. They can damage the tooth and the crown and are not safe to use in the mouth.
• Avoid chewing on that side until the crown is properly recemented.

If a crown comes off and you have pain or swelling, see our dental emergency page or call us right away.

Questions About Your Crown?

If your crown feels loose, has come off, or you are planning new crowns, call Mercer Island Dental at 206-232-3600 or request an appointment. Our office is at 2825 80th Ave SE, Suite 3, on Mercer Island.