A dental crown is a custom-fitted cap placed over a damaged or weakened tooth to restore its function, shape, and appearance. Crowns are bonded securely to the underlying tooth structure, acting as a protective shell against chewing forces. A loose crown indicates a failure of this bond and requires prompt attention. The underlying tooth is vulnerable to bacterial invasion, decay, and fracture without the crown’s protection.
Immediate Steps for Managing a Loose Crown
The first step upon noticing a loose crown is to contact your dental office immediately to schedule an appointment. While waiting for your visit, take careful measures to protect the crown, the exposed tooth, and the surrounding tissues. If the crown has completely come off, carefully retrieve it to bring to your dentist, ensuring you do not swallow it.
If the crown is fully detached, gently clean the inside of the crown and the prepared tooth structure with water to remove debris or old cement. The underlying tooth will likely be sensitive to temperature changes and pressure, so handle the area with care. To temporarily stabilize the crown, purchase an over-the-counter temporary dental cement kit from a pharmacy.
A small amount of temporary adhesive should be placed inside the crown before gently seating it back onto the tooth in its correct orientation. If temporary dental cement is unavailable, a dab of denture adhesive, petroleum jelly, or toothpaste can provide a short-term seal until you see the dentist. Avoid chewing on that side of your mouth entirely to keep the temporary seal intact and prevent damage to the crown or the underlying tooth.
If the crown is only partially loose, do not wiggle it or attempt to pull it off, as this could cause further injury to the tooth preparation. Be careful when brushing and flossing around the area, and maintain a soft diet. Avoid sticky, hard, or crunchy foods, which can pull the crown off completely or fracture the compromised tooth beneath.
Underlying Reasons for Crown Failure
A crown becomes loose when the adhesion between the crown material and the underlying tooth structure is compromised. The most common factor is the breakdown of the dental cement that holds the crown in place, which naturally degrades and washes out over years of use. This loss of cement creates a microscopic space, allowing the crown to move slightly and eventually detach fully.
Tooth decay forming underneath the crown, often called secondary or recurrent decay, is another frequent cause of failure. Bacteria can penetrate the margins, causing the underlying natural tooth to deteriorate. As the decay progresses, it changes the shape of the prepared tooth, causing the crown to lose its precision fit and become loose.
Physical forces also contribute to crown dislodgement, particularly excessive biting pressure. Habits like bruxism (involuntary grinding or clenching of teeth) exert tremendous lateral force that weakens the cement bond over time. Furthermore, a sudden, forceful impact, such as biting down on an unexpectedly hard piece of food or an injury, can fracture the cement or the crown itself, leading to immediate failure.
Dental Treatment Options and Repair
Once at the dental office, the dentist will perform a thorough examination, including a dental X-ray, to determine the cause of the crown failure. The X-ray checks for signs of decay or infection within the underlying tooth structure or around the root. The dentist will also assess the crown for any cracks, chips, or damage that might prevent successful reattachment.
If the underlying tooth is healthy and the crown is undamaged, the most straightforward treatment is recementing the existing crown with a fresh, permanent dental adhesive. This process involves thoroughly cleaning the crown and the tooth preparation to remove all traces of old cement before bonding the crown back into position. Recementing is often the quickest and least invasive solution when failure is due to cement washout.
If the X-ray reveals significant secondary decay, or if the crown is fractured or compromised, a complete replacement is necessary. The dentist will remove the decay and restore the tooth structure before taking new impressions for a custom-made crown. You will wear a temporary crown to protect the prepared tooth while the laboratory fabricates the permanent restoration.
The dentist may also offer preventive recommendations tailored to the cause of the failure, such as providing a custom-fitted night guard to mitigate bruxism. Following these recommendations and maintaining meticulous oral hygiene helps maximize the lifespan of the new or recemented crown.