A dental crown is a custom-made, tooth-shaped cap placed over a damaged or weakened tooth to restore its shape, strength, and appearance. While crowns are designed to be durable and long-lasting, the bond securing them to the underlying tooth can occasionally fail. This article will help you recognize the indications of a loose crown and explain the necessary steps to manage the situation until you can see a dental professional.
Identifying the Signs of a Loose Crown
One of the most immediate signs of a loose crown is a physical sensation of movement, often described as a slight rocking or shifting when touched or when biting down. This movement occurs because the dental cement that once created a secure seal has degraded or fractured. The crown should feel as solid and immovable as a natural tooth, so any perceived wobble is a definitive indicator of an issue.
Sensory changes are a strong clue that the crown’s seal has been compromised. The natural tooth structure beneath the crown, called the dentin, is highly sensitive to temperature and air. Its exposure can lead to a sudden, sharp sensitivity to hot or cold foods and drinks. You may also notice a change in your bite, where the crowned tooth feels slightly uneven when you close your mouth, which can make chewing uncomfortable.
Visual and olfactory changes may also signal a loose crown. A visible gap can appear between the edge of the crown and the gum line, potentially exposing the underlying tooth structure. Furthermore, a foul taste or odor can develop, caused by food debris and bacteria seeping into the space between the crown and the tooth, leading to localized decay or infection. A sudden “pop” while eating sticky or hard food may indicate a complete separation of the crown from the tooth.
Common Reasons Crowns Become Loose
The most frequent cause of a crown becoming loose is the gradual deterioration of the dental cement used to bond it to the tooth preparation. The cement is constantly exposed to moisture, chewing forces, and temperature fluctuations, which weakens the bond over time. This wear means that even a well-placed crown may need to be re-cemented after several years.
Underlying tooth decay is another common reason for crown failure. Although the crown itself is impervious to decay, the remaining natural tooth structure underneath is vulnerable to cavities, especially around the margin where the crown meets the gum line. As decay progresses, it destroys the supporting tooth material, changing the shape of the tooth and compromising the tight fit of the crown, causing it to loosen.
Mechanical forces can also contribute to the loosening of a crown. Habits like teeth grinding or clenching (bruxism) exert excessive, repeated pressure that can break down the cement bond. Trauma to the mouth or biting down on hard foods can fracture the crown or the underlying tooth, leading to dislodgement. Additionally, an imperfect initial fit can result in microleakage that allows bacteria to infiltrate, or the remaining tooth structure may have been insufficient to support a secure bond.
Immediate Actions to Take
If you suspect your crown is loose, the immediate action is to contact your dentist to schedule an appointment. While waiting, you must take steps to preserve the crown and protect the exposed tooth stump. If the crown has completely come off, retrieve it, clean it gently with water, and store it in a secure container to bring to your appointment.
The exposed tooth is often sensitive and susceptible to further damage and decay, so temporary protection is recommended. You can purchase temporary dental cement from a pharmacy. Follow the instructions to clean and dry both the crown and the tooth before attempting to re-seat it. If the crown is undamaged and fits back onto the tooth easily without force, a small amount of this cement can temporarily anchor it in place. If temporary cement is unavailable, a small dab of petroleum jelly or toothpaste applied inside the crown can offer a short-term, makeshift seal.
Avoid chewing on the side of the mouth with the loose crown to prevent swallowing it or causing further damage to the exposed tooth. Restrict your diet to soft foods and avoid anything sticky, hard, or chewy, as these items could pull the crown off or fracture the vulnerable tooth. If you experience discomfort or sensitivity, an over-the-counter pain reliever can help manage the symptoms until you receive dental care.
Dental Procedures to Fix a Loose Crown
Upon arriving at the dental office, the first step involves a thorough examination of both the crown and the underlying tooth, often including an X-ray to check for decay or damage. The dentist will assess the integrity of the crown and the health of the tooth stump to determine the appropriate course of action. The goal is to save the existing crown if possible, as this is the quickest and least invasive solution.
If the crown is intact and the underlying tooth has no significant decay or fracture, the dentist will clean both surfaces thoroughly, removing old cement and debris. The crown will then be permanently re-cemented using a strong dental adhesive, restoring the tight seal and function. This procedure is typically straightforward and completed in a single visit.
If the examination reveals significant underlying decay, the dentist must first remove the decayed tissue and rebuild the tooth structure, often using a core build-up material. If the crown is cracked, fractured, or no longer fits properly, re-cementing is not an option, and a replacement crown will be necessary. In this case, the tooth will be re-prepared, an impression taken, and a temporary crown placed while a new permanent crown is fabricated in a laboratory.