A titration model for evaluating calcium hydroxide removal techniques

Objective Calcium hydroxide (Ca(OH)2) has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH)2 left after different endodontic irrigation methods. Material and Methods Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH)2 for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH)2 recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH)2 followed by gross Ca(OH)2 removal using hand files and randomized treatment of either: 1) Syringe irrigation; 2) Syringe irrigation with use of an apical file; 3) Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI), or 4) Syringe irrigation with apical file and PUI (n=12/group). Residual Ca(OH)2 was dissolved with glycerin and titrated to measure residual Ca(OH)2 left in the root. Results No method completely removed all residual Ca(OH)2. The addition of 30 s PUI with or without apical file use removed Ca(OH)2 significantly better than irrigation alone. Conclusions This technique allowed quantification of residual Ca(OH)2. The use of PUI (with or without apical file) resulted in significantly lower Ca(OH)2 residue compared to irrigation alone

Subcutaneous emphysema in patients undergoing root canal treatment:a systematic review of the factors affecting its development and management

Background: Subcutaneous emphysema is an infrequent mishap during root canal treatment which, in rare cases, can lead to severe complications. Aim: To systematically review the literature on the factors affecting the development of subcutaneous emphysema during root canal treatment, and on its management. Data sources: An electronic search was conducted in EMBASE (1947–2018), LILACS (1982–2018), PubMed (1950–2018), SciELO (1997–2018), Scopus (1970–2018), Web of Science (1900–2018) and two grey literature databases. Moreover, all issues of nine journals and four endodontic textbooks were hand-searched. Study eligibility criteria, participants, interventions: The retrieved studies were screened by two reviewers to select clinical studies, case reports or case series describing subcutaneous emphysema that developed during or immediately after root canal treatment in adult patients. Study appraisal and synthesis methods: Included studies were critically appraised according to a custom list of quality requirements. The extracted data were arranged in tables, and combined through a narrative synthesis. Results: The search retrieved 99 unique articles. Thirty six case reports and 15 case series describing a total of 65 cases of subcutaneous emphysema were included in this review. The methodological quality was medium. Reported cases of emphysema more often involved females and maxillary teeth. Drying of the root canal system with air under pressure, inadvertent extrusion of hydrogen peroxide through the apical foramen, the air-water spray produced by handpieces or laser devices, and the use of ozone gas were the most commonly suspected causes. Its management involved prescription of antibiotics and NSAIDs/analgesics, local application of ice packs or compresses and hospitalization. The signs and symptoms resolved completely within 1-17 days. Limitations: Case reports and case series are a low level of evidence. Conclusions and implications of key findings: Subcutaneous emphysema can develop during both nonsurgical and surgical root canal treatment. Pressurized air streams or air-water sprays should not be directed towards the root canals or areas with mucosal discontinuity. None of the management approaches were clearly related to expedited recovery. Guidelines should be developed in order to avoid unnecessary or potentially harmful interventions