A temporary crown is a protective cap placed over a tooth prepared for a permanent crown. Dentists file down the natural tooth structure to create a stable base for the final restoration. Typically made from acrylic resin or composite material, the temporary crown functions as an interim restoration while the permanent crown is fabricated in a dental laboratory. It is secured with temporary cement, designed to be less adhesive than permanent cement, allowing for easy removal when the final restoration is ready.
The Essential Role of a Temporary Crown
The primary function of the temporary crown is to safeguard the exposed, prepared tooth structure. When the tooth is reduced, the outer enamel is removed, leaving sensitive dentin exposed. This dentin contains microscopic tubes leading directly to the pulp chamber, which houses the tooth’s nerve and blood vessels.
By covering the prepared tooth, the temporary crown prevents bacteria and debris from entering the dentinal tubules, which significantly reduces sensitivity to temperature changes and air. It also acts as a physical barrier to keep the gum tissue (gingiva) from growing into the space prepared for the final crown. If gum tissue grows over the prepared margin, the dentist would have trouble seating the permanent crown correctly, requiring additional procedures. The temporary device also helps maintain proper alignment and spacing in the dental arch, ensuring the final crown will fit precisely.
Risks Associated with Delaying Replacement
The safe period for a tooth to go without a temporary crown is extremely short, measured in hours rather than days. The most immediate risk is the rapid shifting of the prepared tooth and its neighbors. Teeth naturally drift toward any open space, and without the temporary crown acting as a placeholder, the adjacent teeth and the opposing tooth in the other jaw can quickly move into the gap. This movement can occur within 24 to 48 hours, making it impossible for the permanent crown to fit when it arrives from the lab.
If the permanent crown does not fit, the dentist must re-prepare the tooth or have an entirely new crown fabricated, resulting in significant delays and additional costs. Beyond physical shifting, the exposed tooth faces the threat of contamination and infection. Without the protective barrier of the temporary crown, the dentin is vulnerable to oral bacteria, increasing the risk of inflammation in the pulp. This exposure may lead to pulpal necrosis, which could necessitate an unplanned root canal procedure.
The prepared tooth is significantly weaker than an intact tooth, making it prone to fracture under normal chewing forces. The prepared structure is often thinner and lacks the full support of the surrounding enamel, particularly on molars which bear the brunt of biting pressure. Any damage to the underlying tooth can compromise the long-term success of the final crown. The irreversible mechanical changes to the bite and the risk of fracture dictate that the temporary crown must be replaced as soon as possible.
Immediate Steps If Your Temporary Crown Comes Off
If your temporary crown comes off, retrieve it and keep it safe. Contact your dental office immediately, even if the incident occurs outside of normal business hours, as this is considered a dental emergency. The office will want to see you as soon as they can to professionally re-cement the temporary crown.
As a short-term, at-home measure, you can attempt to temporarily re-seat the crown yourself. First, gently clean the inside of the crown and the prepared tooth surface to remove any old cement or debris. Over-the-counter temporary dental cement kits are the preferred option for re-seating and are available at most pharmacies.
If specialized cement is unavailable, a small amount of toothpaste or petroleum jelly can be used as a makeshift adhesive. Place the material inside the crown, align it correctly over the tooth, and bite down gently to fully seat it. You must avoid chewing on that side of the mouth and only consume soft foods until the dentist has secured it properly.