Cracks in teeth range from the obvious, visible fractures (Figure 1a) to less obvious (frequently invisible) microscopic fractures. Frequently, those that are difficult or impossible to see are more serious. Cracks can occur in the crown of the tooth (the part you can see protruding through the gums), or in the tooth’s root, where they can be difficult to diagnose and are generally more serious. Some cracks are easily repaired with bonded fillings, while some are too extensive to be fixed at all.
A bonded filling can sometimes buy enough time for the patient to plan for the expense of a crown. At the time of the photograph, the tooth in Figure 1b had been successfully restored with a filling for a few years. However, it can be difficult or impossible to achieve ideal tooth contours with such large fillings, increasing the likelihood of an overhanging dental restoration, food compaction injuries and other potential problems.
Considering the risk of a fracture spreading through the tooth, the most reliable protection is generally achieved with a full coverage restoration like a crown or onlay. Both of these restorations are made outside the mouth, where it’s usually easier to achieve ideal contours that will blend smoothly with the tooth. Moreover, without the protection of a full coverage restoration, the patient may be at increased risk of losing the tooth if the crack should spread deeper into the tooth.
Only a dentist is qualified to diagnose and appropriately treat the tooth, taking into account the extent of the crack as well as the patient’s symptoms, history, habits, personal needs, presence (or absence) of an opposing tooth, bite relationship between the teeth; and other factors.