2TheApex: Two inferior alveolar nerve blocks (IANB) are more effective than one in both symptomatic and asymptomatic patients.
A recent article published in the Journal of Endodontics showed that administering 2 carpules of local anesthetic was significantly more effective at achieving profound lip anesthesia. 3169 people participated in the study with failure rates of 7.7% with one carpule, and 2.3% with two carpules of 2% Lido with 1:100,000 epi. Although this may seem like common sense, it is the first article to show that increasing volume will increase IANB success rates. This study only examined anesthetic success in terms of lip numbness, not as a pain free procedure. As we all know, pain can still be present during the procedure even with profound lip numbness. However, adequate anesthesia will almost never be achieved without first achieving lip numbness as a sign of a successful IANB first.
If a patient has been taking Ibuprofen symptoms can be masked. Read found palpation to be masked up to 40% of the time. Cold response was masked 25% of the time. Be sure and ask patients if they have been taking any NSAIDs and at what dosage prior to pulpal testing. The bite stick test is one test that seems to be least affected by taking NSAIDs. We encourage patients to cease taking any pain medication at least 6 hours prior to the appointment if it sounds like the diagnosis might be challenging.
2TheApex: Most of the time a tooth with pulp canal obliteration does not need root canal therapy. Signs and symptoms determine treatment.
Just because a tooth has calcified does not mean it is or will become necrotic. Quite the contrary. According to Andeasen, 22% of traumatized undergo calcific metamorphosis. Holcomb and Gregory found that only 7% become necrotic. They recommended treatment only if a periapical lesion developed. Walton found that a pulp space is always present histologically even if it is not visible radiographically. Negotiating a “histologically present” canal does not make for a fun afternoon. (unless you are an endodontist working on keeping your finger calluses)
Pulpal testing should not be trusted with calcified teeth. Most of the time a tooth with pulp canal obliteration will be nonresponsive to cold testing. Electric pulp testing cannot be trusted. Jacobsen found that only 50% of the time a vital calcified tooth would have a positive response to electric pulp testing.
Many times poor aesthetics of a calcified tooth is the chief complaint. The darker shade of the tooth is due to the increase of dentin thickness and not necessarily an indication of necrosis. Elective treatment with internal bleaching can be completed to correct this in many cases. To get an exact shade match a veneer may be best.
2TheApex: Cold testing is 90% accurate in determining pulp vitality.
Diagnosis can be one of the most challenging aspects of endodontic treatment. The most commonly used test to determine pulpal status is the cold test. There are several different methods to perform a cold test including: refrigerant spray (Endo Ice), ice, cold water, and CO2 sticks. Here are some general tips for cold testing:
- Always dry and isolate the teeth to be tested.
- Don’t trust that the patient knows what tooth hurts, studies show only 37%-73% accuracy in patients correctly identifying teeth with pulpitis.
- Start with a normal adjacent or contralateral tooth as a control. This gives the patient a reference for the test, allows you to judge their reaction with a normal pulp, and aids in correctly identifying the source of the patient’s discomfort.
- When possible, testing on the facial surface of the tooth allows for the most accurate results.
- When using refrigerant spray, use a large, loose, cotton pellet held in a cotton pliers to maximize temperature change. Avoid using cotton tip applicators because the tightly bound fibers do not transfer temperature change adequately.
- If using ice, always start with the most posterior tooth, as cold water will run back and may illicit a response from a tooth other than that being tested.
- Teeth with crowns and large restorations will most often still respond accurately to a cold test.
Remember that pulp testing is not a direct measure of the histological condition of the pulp, but rather a test based on the patients response to an external stimulus. Approximately 10% of cold tests will yield incorrect results, and should not be relied upon as the sole indicator of pulpal status. The patient’s medical history, reported symptoms, previous dental history, clinical findings, and radiographic examination must all be utilized to arrive at an accurate diagnosis. Cold testing, while an indispensable tool, is just one part of our diagnostic tool kit.