Subcutaneous Emphysema Caused by Sodium Hypochlorite plus RC-Prep

Introduction: “RC-Prep”, a chemo-mechanical preparation for root canals, includes EDTA and urea peroxide as ingredients. For lubrication and its chelating effect, RC-Prep is useful as an adjunct in root canal enlargement. Furthermore, its cleaning action, due to its foaming properties in combination with sodium hypochlorite, can be useful in root canal treatment in many situations. Methods: In a case of upper gingiva swelling, we used sodium hypochlorite with RC-Prep in the treatment of an infected root canal of the left maxillary premolar at the first visit. Within 2 min after use, the patient’s face became swollen. We kept the root canal open, and conducted a CT scan to investigate. Results: We diagnosed subcutaneous emphysema and prescribed 1 week of pain killers and antibiotics. The pain and swelling in the face finally resolved at 11 days after the incident. Conclusions: The cause of the emphysema was considered to have been the use of a sodium hypochlorite solution after using RC-Prep for an opened root apex.