Effectiveness of single- versus multiple-visit endodontic treatment of teeth with apical periodontitis: a systematic review and meta-analysis

Aim The clinical question this review aimed to answer is: does single-visit root canal treatment without calcium hydroxide dressing, compared to multiple-visit treatment with calcium hydroxide dressing for 1 week or more, result in a lower healing (success) rate (as measured by clinical and radiographic interpretation)? Methodology CENTRAL, MEDLINE, EMBASE and HEALTH STAR databases were used. Reference lists from identified articles were scanned. A forward search was undertaken on the authors of the identified articles. Papers that had cited these articles were also identified through Science Citation Index to identify potentially relevant subsequent primary research. Review methods The included studies were randomized controlled clinical trials (RCTs) comparing healing rate of single- and multiple-visit root canal treatment in humans. The outcome measured was healing of radiographically detectable lesions. Data in those studies were independently extracted. Results Only three RCTs were identified and included in the review, covering 146 cases. Sample size of all three studies was small; none demonstrated a statistically significant difference in healing rates. Risk differences of included studies were combined using the inverse variance-weighted method (RDPooled = -6.3%; 95% CI: -20.3-7.8). Conclusion Based on the current best available evidence, single-visit root canal treatment appeared to be slightly more effective than multiple visit, i.e. 6.3% higher healing rate. However, the difference in healing rate between these two treatment regimens was not statistically significant (P = 0.3809).