Extrusion of endodontic materials

 I had an endodontic mishap the other day which I am waiting to follow up to see the result of. The case was an extirpation of an upper lateral incisor. Due to the severe caries ring barking the tooth I cleared the decay and restored the tooth before placing a rubber dam. This is to ensure that the rubber dam seals against convex restoration rather than concave caries as well as for restorative ease to clear caries without the risk of catching the rubber dam on the bur and before rubber dam placement causes gingival bleeding. One thing I have done in the past is to avoid opening the pulp chamber before placing the rubber dam to avoid contamination of the pulp but realistically this isn't so much of a big deal if a dry field is kept and likely the root canal space is already infected. Instead, leaving caries to remove after restoration may result in more difficult access and a more difficult procedure. I place cavit over the caries to mark where I have to drill and to make reaccessing the caries easier. After restoration with a GIC, I placed the rubber dam and accessed the pulp chamber. This is more difficult as I lost orientation of where tooth structure and restoration met. If I had accessed the pulp before restoration I could place cavit in the pulp chamber in the shape of the access cavity and remove this with ultrasonics after restoration and my access would already be completed. 

I reaccessed the tooth but had difficulty clearing caries as the restoration was in the way and ended up making quite a narrow access cavity as I didn't want to remove too much more tooth structure to access it and the restoration made the visual access more difficult. The narrow access led to several problems. I extirpated the pulp including an intrapulpal injection because the pulp was quite inflamed. I irrigated with NaOCl and didn't bother dry with paper points because the access was difficult getting a point in. I placed calcium hydroxide in the pulp chamber but had difficulty getting it down because of the lack of access. In future I would be very careful to clear the irrigant from the pulp space before placing a medicament as the irrigant would dilute the medicament and take space for it to be introduced into the root canals. I used a file to push the medicament down and placed cavit over this. As the access was very narrow the cavit had a hermetic seal right at the cavo surface margin. I then took a plugger and pushed the cavit down the cavity. At this point the patient jumped with pain and had a lasting pain in the gum above the tooth. I surmise that I forced either hypochlorite, calcium hydroxide, air or a combination of these out of the tooth with positive pressure. 

Concerns with this event are a "surgical emphysema", hypochlorite incident or tissue necrosis due to calcium hydroxide extrusion. What I would change in the future to avoid this happening again would be to:

-Remove all caries before restoring

-Place substantial cavit to allow easy reaccess

-Make sure that enough restoration is removed around the access to provide good vision and to allow easy instrumentation

-Dry the canal before placing medicament

-Place the cavit layer down at the base of the preparation before allowing it to contact all walls and form a seal to avoid positive pressure. If the access is narrow, use a cotton pellet to wick up excess medicament, place it in the access but don't force it down, use a probe to push the cavit to one side of the access to break the seal and only then push it down

I will await the next appointment with the patient to follow up how the complication went in the days following the procedure