Patient, tooth, and dentist characteristics associated with multi-visit nonsurgical root canal treatment: findings from the National Dental Practice-Based Research Network

Background: Identifying factors linked to multi-visit nonsurgical root canal treatment (RCT) may help distinguish cases that warrant staging from those suitable for single-visit treatment. This study examined patient-, tooth-, and dentist-level characteristics associated with multi-visit RCT. Methods: Data were analyzed from 1723 patients enrolled in the National Dental Practice-Based Research Network study. The primary outcome was completion of RCT in more than one visit. Patient demographics, preoperative symptoms, clinical and tooth characteristics, procedural difficulty, and dentist factors were evaluated for their association with multi-visit RCT completion using multivariable generalized estimating equation models accounting for clustering of patients within dentists. Results: Overall, 316 patients (18%) received more than one visit. In the final adjusted model, multi-visit RCT was independently associated with academic or public practices (OR= 2.98; p=.03 ) in the Northeast region (OR=2.59; p=.02). Patient-level factors included Asian or Hispanic race/ethnicity (OR=1.68; p=.02) and severe preoperative tooth pain (OR=1.66; p=.002). Tooth-level characteristics associated with multi-visit treatment included molar tooth type (OR=2.08; p<.001), mandibular location (OR=1.37; p=.02), presence of swelling (OR=1.60; p=.04), and tooth movement (OR=1.59; p=.048). Characteristics inversely associated with multi-visit treatment were the tooth being vital (OR=0.48; p<.001) and being tender to biting pressure (OR=0.73; p=.04). Conclusions: Multi-visit RCT reflects clinical complexity, symptom severity, dentist and patient factors, supporting case-based rather than routine treatment decisions. Clinical significance: Recognizing the clinical factors associated with multi-visit RCT may help dentists distinguish cases that truly warrant staging from those appropriate for single-visit treatment, promoting more consistent evidence-informed care.