Dennis Brave, DDS and Kenneth Koch, DMD
One of the most perplexing problems in endodontics is the patient with a painful tooth that lacks a diagnosable cause. Generally, patients complain of pain sharp enough to make them flinch when they bite down. X-rays and pulp tests yield no clue; everything seems normal. Believe it or not, you probably are dealing with a cracked tooth.
The mandible second molar is the most commonly cracked tooth, particularly when in occlusion with a maxillary crown. The pain, especially with mastication, can be severe. Also, teeth with large amalgam restorations are typically cracked due to unsupported tooth structure. Think how often you see crack lines around the restorations.
What are the most common causes of "cracked tooth syndrome?" In our opinion, popcorn is the number one cause. The hard kernels in the bottom of the bag are the main culprits.
The second most common cause of cracked teeth is ice. Those who habitually munch ice (tea drinkers in warmer climates!) are particularly vulnerable.
Schools and texts historically have taught several techniques to diagnose cracked teeth, including biting upon wet cotton rolls, chewing on a saliva ejector, or even chewing on a piece of burlew wheel. A burlew wheel is actually used in dental laboratory work and we definitely do not recommend chewing on it!
A simple apparatus called a "tooth slooth" is the best tool for diagnosing a cracked tooth. The "tooth slooth" is a plastic bite stick that has a concavity on one end that can be placed over individual cusps. For a cracked lower second molar, the patient bites down on the "tooth slooth" when placed over the MB cusp. If there is no response, we go on to the DB cusp, and proceed until the offending tooth is found. The patient bites down and, upon release, experiences a sharp pain that duplicates the chief complaint. This is the cracked cusp.
The treatment for a cracked tooth actually is a casting. A cracked tooth does not automatically mean a root canal. If there is pulpal involvement, place a well-fitted, adjusted temporary crown on the involved tooth and re-evaluate in two to four weeks. If the pain totally vanishes, proceed with the prosthetic. However, if the tooth is constantly symptomatic and is sensitive to thermal changes, the patient gets a ticket to "Endo City."
Real World Endo Tip: Get a "tooth slooth" and learn how to use it. This will earn endodontic practitioners the gratitude of their satisfied patients, especially when they learn that they won't need a root canal.
Fractured teeth have become an increasing problem. Some are the result of poor post design, inadequate post preparation, lack of proper restorations, and, in some cases, overzealous removal of tooth structure during a root canal. A fractured tooth generally will have pain upon biting, a feeling of movement in the tooth, or, in the case of a totally split tooth, pain or a pulling sensation in the gingival tissue.
To diagnose a fractured tooth, first, check with a perio probe. If the tooth probes 556655, this is perio. However, if the tooth probes 222722, this most likely is a fractured tooth.
A single deep probing is pathognomonic of root fractures. Another diagnostic tip is the shape of the lesion on the X-ray. Fractured teeth generally have a "halo-like" lesion around the involved root. Some might describe it as "teardrop" in shape. A single, deep probing in conjunction with a halo-like lesion often indicates a fractured tooth.
The treatment for a fractured tooth is extraction. We have tried various methods of "hero-dontics," such as filling the tooth with glass ionomer or repairing the crack with a composite resin, with limited success. Certainly, dentists won't risk such a tooth as part of your crown and bridge treatment plan.
Dr. Dennis Brave is a diplomate of the American Board of Endodontics and was the senior managing partner of a group specialty practice for 27 years. Dr. Kenneth Koch is the founder and past director of the new program in postdoctoral endodontics at the Harvard School of Dental Medicine. Drs. Koch and Brave together are Real World Endo, an endodontic education company. They can be reached at (866) RWE-ENDO, or visit their Web site at RealWorldEndo.com.