Investigating the prevalence of a second mandibular incisor root canal in CBCT and periapical graphies in Shiraz

Accurate knowledge considering root canal morphology is critical in performing standard root canal treatment. Human permanent mandibular incisors usually have a single root with a single canal, but sometimes, second canal is probable, which causes a failure in endodontic treatments. In clinical situations, conventional periapical radiography is commonly used to study the root canal morphology  but the limitations of periapical radiography have led to significant interest in cone-beam computed tomography (CBCT). The purpose of this study is to compare the ability of PA radiographs and CBCT in showing the number of the mandibular incisor canals.

In this cross-sectional study a total number of 292 CBCT and PA radiographs from mandibular incisors were taken from 73 patients (41 females and 32 males). These radiographs were gathered from patients who needed CBCT and PA examinations as a part of their treatment procedure. Two dental students trained by a board certified oromaxillofacial radiologist separately examined the PA and CBCT images in axial, coronal and cross-sectional views. Data analysis was performed using student T-Test.

The results from observing CBCT views showed that the majority of mandibular incisors (78.4%) had one canal and the rest demonstrate two root canals. None of these teeth demonstrated two root canals in the PA radiographs. Presence of a second canal was more likely in central incisors in comparison with lateral incisors and it was also more common in males than females.

Although PA radiographs is a routine method for endodontic treatments, when an endodontic treatment fails or there is a possibility of existence of second canal, CBCT is recommended.