One of the first questions that I will ask someone during an exam is: “Are you having any sensitivity to temperature, sweets or any biting pain?” One of the primary reasons I ask is because these can be symptoms of a cracked tooth. If you are experiencing tooth sensitivity localized to one area, particularly if it comes and goes, then you may very well have a cracked tooth.
Why do cracks cause pain?
The outer layer of tooth, the enamel, does not normally transmit sensitivity or pain. However, when the underlying tooth structure, dentin, is exposed, sensitivity will occur. This can be the result of a cavity, a leaking filling, tooth wear or a crack, among several other causes.
When do cracks occur?
Most commonly, a crack will occur adjacent to a larger filling that has been in the tooth for many years. When tooth structure is removed, a tooth is weakened. Most fillings do little to strengthen the tooth and leave it very vulnerable to cracks. This is most commonly the case with the older silver fillings, which do not bond to the tooth and tend to be larger than today’s bonded, tooth-colored fillings. Over many years of service, weakened tooth structure surrounding a filling will begin to crack. If the crack remains only in the outer enamel, it is unlikely to be a problem. However, if that crack begins to penetrate deeper, under the filling and into dentin, sensitivity will ensue and the risk of further problems increases greatly.
Beyond sensitivity, why are cracks a problem?
Though cracks can be very small and difficult to see with the naked eye, they are large enough to allow bacteria to travel into the tooth and form a cavity. This can be true even for those people with a low susceptibility to decay. As the crack travels deeper, it can create inflammation within the pulp of the tooth, where the nerve and blood supply are. This can lead to a severe toothache and the necessity for a root canal. Should the crack progress further, the tooth can break. If the break is severe enough, the tooth must be removed. To prevent root canals and tooth loss, it is always best to treat a cracked tooth as early as possible.
How is a crack diagnosed?
It is not always easy to diagnose a crack, and as a result they are often missed. Cracks are not visible on x-rays and because the deep (dentin) cracks most often occur under fillings, visual inspection is very difficult as well. Also, since the symptoms tend to come and go, it is very common that they may not be present by the time a person comes in for an exam. Therefore, diagnosing a crack is the result of putting all available evidence together. The key things that we look at are the size of the existing filling, the presence of any superficial cracking, and pain to temperature, sweets or biting. An intraoral camera is used both to track these problems over time as well as to show patients teeth that may be at risk for cracks.
How is a cracked tooth treated?
If the crack is severe enough, a root canal or even extraction may be necessary. This is why it is important to catch the crack early. Traditionally, these early to moderate cracks would be treated by placing a crown over the top of a tooth to strengthen the tooth and reduce the stresses that cause the crack to progress. In cases of early cracks, modern materials and techniques allow us to repair a crack more conservatively with a bonded tooth colored “biomimetic restoration.” “Biomimetic” means life-like, and compared to a conventional crown, they certainly are. This is because they require a minimal amount of tooth structure removal and are customized to each situation to act more like a tooth. The result is a tooth that is less prone to further problems, such as root canal issues, at a significant cost savings over the conventional crown.