1. Diagnosing Cracked and Fractured Teeth
Cracked teeth are common sources of diagnostic difficulty and patient discomfort. The “tooth slooth”, a plastic bite stick, is the most effective tool for identifying cracks. When a patient bites and feels pain upon release, it indicates a cracked cusp.
Common causes: Hard popcorn kernels and habitual ice chewing.
Typical tooth: Mandibular second molar.
Common symptom: “It only hurts when I bite down a certain way.”
Radiographic challenge: X-rays often appear normal.
Treatment guidelines:
Most cracked teeth require crowns.
If the crack extends into the pulp or produces lingering thermal sensitivity, root canal therapy is indicated.
When uncertain, place a temporary crown and re-evaluate in two weeks—persistence or worsening of symptoms warrants endodontic treatment.
2. Differentiating a Fractured Tooth
A fractured tooth extends through the root structure and requires extraction.
Diagnosis relies on periodontal probing and radiographic findings:
A single deep probing site (e.g., 22722) indicates a fracture.
A diffuse, multi-site probing (e.g., 45545) suggests periodontal disease.
Radiographs may show halo-shaped radiolucency or a fistula near the fracture site.
Diagnosing fractured tooth is never straightforward and is actually the most difficult to diagnose. I also recommend taking multiple angle radiographs and take CBCT.
3. Don’t Overlook Periodontal or Occlusal Pain
Periodontal pain is dull, chronic, and poorly localized; abscesses are found high in the gingiva.
Occlusal trauma often follows recent restorative work and presents as sharp pain to cold or biting. Adjusting the occlusion usually resolves symptoms.
Failure to recognize these issues can result in unnecessary endodontic treatment—and frustration for both dentist and patient.
4. The #1 Cause of Endodontic Disaster: Inadequate Anesthesia
The inability to achieve profound anesthesia is one of the most common and preventable causes of failed root canal appointments. A “numb” patient equals a relaxed, efficient, and profitable procedure.
Key anesthesia principles:
Never start treatment if the patient is sensitive to a rubber dam clamp.
Administer two mandibular blocks routinely.
Be proficient in multiple anesthetic techniques—never rely on one approach.
5. Advanced Anesthetic Techniques
a. Sequential Block Technique (pKa principle)
Inject 3% Mepivacaine (Polocaine) first – its higher pH offers greater comfort and faster onset.
Follow with 2% Lidocaine with 1:100,000 epinephrine – for a deeper, longer block.
b. Mylohyoid Nerve Anesthesia
Persistent pain despite adequate blocks may stem from the mylohyoid nerve (often affecting mandibular molars).
Two supplemental methods:
Gow-Gates technique: Long needle aimed toward the condylar neck; effective, avascular, and provides broad anesthesia.
Lingual infiltration near the apex of the lower second molar; inject slowly due to vascularity.
c. Supplemental Injection Techniques
PDL (periodontal ligament) injection: Small volume placed against bone; works via vasoconstrictor effect (use 1:50,000 epi). Provides ~10 minutes of profound anesthesia.
Intrapulpal injection: Use a 30-gauge needle and a new bur for minimal discomfort. Works via pressure, even with saline.
Intraosseous injection (Stabident or X-Tip system): Drill through cortical bone into cancellous space for immediate anesthesia lasting 10–15 minutes. Inject slowly (max one carpule) to avoid cardiovascular effects.
6. Key Takeaways
Diagnose cracked vs fractured teeth accurately using the tooth slooth and periodontal probe.
Address periodontal or occlusal issues before assuming pulpal origin.
Master multiple anesthesia techniques—especially Gow-Gates, PDL, intrapulpal, and intraosseous approaches.
Profound anesthesia prevents frustration, saves time, and ensures patient comfort—critical for avoiding true “endodontic disasters.”
In Summary
Endodontic “disasters” often arise not from technical skill but from misdiagnosis or poor pain control. Recognizing crack patterns, verifying fractures, and mastering advanced anesthesia methods transform stressful, unpredictable cases into efficient, comfortable, and profitable procedures. The next article in the series explores iatrogenic complications such as perforations and separated instruments.
