Loose dental crown is a common problem which is encountered by the patients after getting dental crown. Life span of dental crown is 5-15 years but it may fall before. Dental crown can fall off from the underlying tooth structure in case of dental caries below the dental crown which can occur by accumulation of plaque and calculus deposits around the edges of the dental crown, lack of tooth structure support to hold the dental crown, ill fitting dental crown, more of unnatural stresses on dental crown because of clenching or grinding of teeth or using teeth as tools or can occur if the permanent luting cement which is used by the dentist is not strong enough or gets contaminated during fixing dental crown to the tooth structure. Dental crown is more likely to fall because of the reasons listed above. Various causes which can lead to fall of dental crown are discussed in details below.
Various reasons which can cause loosening and fall of dental crown are:
1. Decay under Dental Crown
Many people think that once they get dental crown, they can’t get dental caries but it is not true. The underlying tooth structure to which dental crown is given can get decayed. By accumulation of plaque and calculus deposits on the areas beyond the edges of dental crown, dental cavity can start. To remove the cavity from the tooth, the dentist will firstly have to remove the existing dental crown and after removing the dental caries from the tooth, new dental crown may be required by the patient. If the caries which are present below the dental crown are deep or are too close to pulp which has nerves, then root canal procedure will be required for the tooth. If there is severe gross tooth decay present, then tooth extraction may also be required. Crown lengthening procedure may also be required by the patient. It is a cosmetic procedure which will make teeth look longer than what they are by removing excess of gum tissue. Crown lengthening procedure will expose more of tooth’s crown which will further support dental crown.
2. Lack of Tooth Structure to hold the Dental Crown
After selective grinding of tooth from all sides, dental crown is given on the tooth. If the tooth structure to hold the dental crown is less, then it can cause dental crown to fall off repeatedly. If the prepared tooth is too small to support the dental crown, then it can cause dental crown to fall. Stability against lateral forces will become less in case of tooth with less of tooth structure. This is more common in case of back teeth as compared to front teeth.
3. Ill-fitting Dental Crown
If the dental crown which is made by the dentist has an improper fit, then it can lead to fall of dental crown. If the dental crown is ill-fitting, then patient has to get his ill fitting dental crown replaced with new dental crown.
4. Permanent fixing cement used by dentist was not of good quality
If the dental cement which is used by the dentist is not that strong or is not of good quality or is contaminated when it was prepared, then the dental crown may fall off after some time. In such a case, dentist will re-cement the dental crown on to the underlying tooth structure with permanent fixing cement.
5. More of Stresses on Dental Crown
If the patient is in the habit of clenching or grinding his teeth or if teeth are used as tools by the patient, then it can lead to fall of dental crowns. Dental crown is held to the underlying tooth structure with permanent luting cement and bond exists between the tooth structure and the dental crown. If the tooth is subjected to excessive forces, then this bond between the tooth and the dental crown will become weak and dental crown will fall off the tooth. Dental crowns fall off repeatedly in patients of bruxism.
Grinding or Clenching of Teeth Can Cause Dental Crown to fall
6. More of forces on Dental Crown which can even break Dental Crown
Excessive forces on dental crown can cause loosening and fall of dental crown. Excessive forces on dental crown can even lead to crack formation on dental crown or leads to loosening of dental crown which will cause dental crown to fall off the tooth. If a dental crown has cracked, then it is evaluated by the dentist. Cracked dental crown can be repaired by buffing the area if the crack is small otherwise replacement of dental crown is required.
7. Excess of Sticky and Chewy Food
Excessive consumption of sticky foods like caramels, chocolates, chewing gums, candies can cause dental crown to become loose and fall. Sticky food in excess amounts can grab and pull off the dental crown. If the dental crown falls off because of excessive consumption of sticky foods, then the dentist can re-insert the dental crown by recementing it on the underlying tooth structure.
Life span of dental crowns is 5-15 years which further depends on the amount of wear and tear of the dental crown, maintenance of good oral hygiene by the patient and various habits of the patient like clenching and grinding of teeth, biting fingernails, chewing on ice etc. If the dental crown falls off, then patient can see his dentist. A loose dental crown can either be recemented or reluted or may have to be replaced. If the dental crown which came off the tooth is hollow from inside, then patient can use a temporary crown cement to glue the dental crown to the underlying tooth structure after consulting the dentist.