Interradicular Canals in 213 Mandibular and 235 Maxillary Molars by Means of Micro-computed Tomographic Analysis: An Ex Vivo Study

Introduction: Bacteria and/or toxin residuals in the furcation areas of mandibular and maxillary molars can be the cause of persistent periapical tissue inflammation before or after an endodontic treatment. Methods: The objective of this ex vivo study was to investigate the frequency of interradicular canals and diverticula in first and second mandibular and first and second maxillary molars by means of micro-computed tomographic imaging. Five hundred thirteen extracted molars, 211 mandibular molars and 302 maxillary molars, were included in this investigation. The area between the pulp chamber floor (PCF) and the furcation area was examined, and the data obtained were evaluated with imaging software that generated the corresponding 3-dimensional images. The results were analyzed by means of descriptive statistics. Results: Interradicular canals were observed in 2.8% and 0.3% of the mandibular and maxillary molars, respectively. The diverticula (blind-ended interradicular canals) originated either at the furcation area or at the PCF. The diverticula frequency observed in mandibular molars was 3.3% (PCF) and 4.3% (bifurcation). The maxillary molar diverticula frequency observed was 2.0% (trifurcation), with none of them originating at the PCF. Altogether (n = 513) diverticula originated more frequently from the PCF (59.1%) than from the furcation area (40.9%). Conclusions: Although interradicular canals as well as diverticula were observed in a relatively small number of the investigated molars, practitioners should always be aware of their existence because without an adequate chemical debridement/disinfection of the pulp chamber root canal system, successful endodontic treatment could be compromised in up to 10% of the cases.

Automated summary

This study investigated the frequency of interradicular canals and diverticula in mandibular and maxillary molars. The results showed that the frequency of diverticula originating from the pulp chamber was higher than those originating from the furcation area. Clinicians should be aware of the existence of diverticula to ensure successful endodontic treatment.