Patient presented with #1.3 pulp necrosis and chronic apical abscess. Due to missing #1.2, mesially tilted tooth #1.3 had been restored as #13-#1.4 splinted crowns in the place of #1.2 and #1.3. The clinical picture shows a ceramic interdental papilla which covers the root of tooth #1.3.
The key aspects in treating such a case are as follows:
reviewing the risks of the procedure in detail with the patient (i.e. possible damage to the restorative work to the point of needing replacement, possible mishaps during the endodontic treatment [perforation, instrument fracture], etc.)
through assessment of the tooth/root under the crown using a probe and by palpating the root
good understanding of the root angulations in mesial-distal and buccal-lingual directions
planning for initial access location
good isolation with a stable clamp that can be placed over the root
constantly aligning the bur with the long access of the root while drilling in the center of it
and finally, Patience, Patience and more Patience!
In my previous post “The Little Devil Horn,” I showed a case of fractured Dens Evaginatus (DE) that had resulted in pulpal necrosis in an 11 years old girl. In almost all cases the tubercles fracture off as soon as the teeth come into occlusion. The resultant pulp exposure goes unnoticed until patient develops pain and symptoms and a combined endodontic-restorative procedures would then be necessary. Therefore, just observing what does not belong to a proper occlusion is not a good choice.
The endodontic treatment for necrotic teeth with immature roots is either regenerative endodontics or MTA apexogenesis depending on many factors. The latter was used to treat the case of fractured DE with pulpal necrosis.
So, what should we do if we face a vital tooth with an intact tubercle?
Some evidence suggest a gradual shaving off the tubercle over a period of few months in order to allow tertiary dentin formation is the treatment of choice. However, tertiary dentinogenesis may not provide a complete seal of the pulp chamber as this process lays down an irregularly formed dentinal structure.
Another approach would be to remove the tubercle mechanically under RD isolation and to seal off the resultant mechanical exposure, if any, with bonding material. This approach was performed for the same young patient for tooth #3-5.
The maxillary canine space can become directly involved as the result of infections from the maxillary canines. The infection from these long teeth can involve the canine space, the area superior to the muscles of facial expression. The resultant swelling obliterates the nasolabial fold on the affected side [obliteration of the nasolabial fold on the right side of patient’s face in the image below].
Superior spread of CSI, if not treated, may cause orbital/periorbital cellulitis or cavernous sinus thrombosis, both very serious infections requiring aggressive surgical interventions. Emergency treatment for such infections include establishing drainage [detail described in previous post “Don’t Let the Sun Set on Pus!“], removing the source of infection through access, instrumentation, irrigation and placing intracanal medicament and prescribing antibiotics if indicated. Antibiotics alone is not sufficient.
Dens evaginatus (a.k.a. Leong’s premolar) is an odontogenic developmental anomaly. This anomaly, an enamel-covered tubercle with an extension of pulp horn in most cases, occurs primarily in premolars. Loss of this tuberculated cusp during natural root maturation and development will result in early pulp exposure, pulpal necrosis, periapical disease, and arrested root development. Early diagnosis and management of dens evaginatus is therefore the key factor in preventing premature loss of tooth vitality.
When deciding on an endodontic-restorative plan for a tooth, one should always keep in mind the age of the dental pulp (i.e. patient’s age). Younger dental pulp = more cellular, vascular, defensive and therefore resilient. This fact can help us decide on a more appropriate and conservative treatment for a tooth when facing pulp exposure as a result of trauma or caries excavation.
Vital Pulp Therapy (VPT) techniques is attempted in order to remove the reversible pulpal injury, to preserve the vitality of the pulp and to ultimately allow continued root/tooth growth. The technique comprises: a) good isolation, b) complete caries removal, c) disinfection of the access cavity with NaOCl, d) stopping the bleeding with a moist cotton pellet, e) applying pulp capping material such as ProRoot® MTA or Biodentine™, and f) restoring the access cavity with permanent restoration after confirming the setting of the capping material.
In the above case Direct Pulp Capping with MTA, irrespective of the size of carious exposure, was performed because this 13 year-old patient presented with non-lingering, non-spontaneous and reversible pulpitis symptoms. In addition, carious exposure resulted in fresh bleeding from pulp horns that could be stopped with applying moist cotton pellet. If a patient presents with irreversible pulpitis symptoms, other VPT techniques should be considered.
The only non-precious stone that I know is the pulp stone. One of the factors contributing to root canal failure is remaining infected pulp tissue and the pulp stones, if left behind unnoticed, are the main reason for trapping tissue and retaining infection. Pulp stone removal is therefore a crucial factor in achieving a successful result in endodontic treatment. The following case shows how a large pulp stone can result in failure of a reasonably well done root canal treatment by trapping infected tissue, hiding the MB2 canal and retaining infection.
Proper access cavity (i.e. adequately large and at the level of the CEJ) in order to visualize the outline of the pulp stone/chamber floor is the key in removing it completely. In the above example the pulp stone is easily dislodged by troughing around it using a large diamond-coated ultrasonic tip and applying the energy directly to the calcified tissue. For demonstration and documentation purposes, no water was used in this case; however, it is highly recommended to use water for its cooling effect and in order to facilitate the debris removal.
If you attended my lecture at the Pacific Dental Conference last month, I mentioned “The Laws” that allow us to safely and predictably locate canals without being worried about mishaps (i.e. perforations, over-enlarged access cavities, etc.). One of the scenarios that we have to always be prepared for is accessing through a crown that is placed on a rotated tooth. One of the key elements discussed was the use of a probe to gain a better appreciation of the root outline at the CEJ level. The “Law of Concentricity” then allows us to start our access cavity preparation in the right direction.
The case below shows a rotated tooth #1-4 under a PFM crown. Preparing a typical access cavity in the Buccal-Lingual direction would definitely result in mishaps. Understanding the orientation of the tooth prior to the start of root canal treatment can result in achieving a safe and a conservative access prep. Note that even the rubber dam clamp wings are not good guides for the orientation of the chamber floor and for locating canals.
Heavy bite, specially with less than ideal occlusion or cusp-fossa relationship, can result in cracks and fractures in teeth. Here is an example of a case with heavy occlusal pressure concentrated on the lingual inclinations of the buccal and lingual cusps of tooth #2-4. Two mesial enamel cracks are evident in this case.
Lets imagine the following scenario if we do nothing for this asymptomatic tooth:
With time, the cracks propagate and involve the pulp chamber. Based on the position of the existing restoration, a tooth split may result no matter how innocent (don’t blame the amalgam fillings). Clinical symptoms (pulpitis) appear. Root canal is done and the initial sensitivity symptoms do resolve. A crown is then fabricated for a possibly deeply cracked tooth. The biting tenderness however persists post-endodontic treatment. If the patient is lucky not to go through further unnecessary treatments (i.e. retreatment, apical surgery, etc.), the tooth will eventually be replaced with an implant. And, this is one of the reasons why root canals get their poor reputation. “Root canals don’t work”, “every root canaled tooth fractures”, or the most insulting to my profession that I have ever heard: “root canaled tooth is an eventual space maintainer for an implant.”
So, lets contemplate the above scenario and think about prevention and saving teeth instead.
Excessive root dentin removal during endodontic treatment and use of posts are the predominant risk factors for root fractures. Common clinical findings associate with root fractured teeth have been discussed in a previous post (It is ‘Game Over’!)
Vertical root fractures are usually detected through careful probing around a tooth but sometimes all you need is air-water syringe.
Sometimes when the conventional endodontic access is not possible, the unconventional approach can save the day.
A clinician should always aim at establishing a straight line access (SLA) in order to properly instrument, irrigate and obturate the canal system. Depending on the initial challenges, establishing a SLA could mean accessing an anterior tooth through its buccal surface [example below], accessing an anterior tooth through its incisal edge, or accessing a molar tooth through its mesial marginal ridge or its MB cusp.