Micro-CT Analysis of the Root Canal Configuration of Maxillary Second Molars with Fusion

Abstract

Purpose: The present study investigated the root canal configuration of maxillary second molars with root fusion using micro-computed tomography (micro-CT).
 Materials & Methods: A total of 136 fused maxillary second molars were scanned with micro-computed tomography. Images were transferred to CTAn v.1.18.8 software (Bruker-microCT) to obtain three-dimensional models. The specimens were classified according to the fusion type. According to Vertucci, classification of the root canal configuration of fused roots was determined using CTVol v. 2.3.2.0 (Bruker-microCT) and DataViewer v.1.5.6 (Bruker-microCT) softwares. The specimens that could not be represented were also specified. The frequency of canal configuration according to the fusion type was calculated.
 Results: For Type 1 fusion (n=40) and Type 2 fusion (n=22), the most common canal configuration for mesiobuccal (MB), distobuccal (DB) and palatal (P) canals was Type I. In type 3 fusion specimens (n = 21), DB and P canals were completely fused in 1 sample in accordance with Vertucci type IV, while in the remaining specimens, types II, I, V, VI and IV were observed in decreasing order in the MB canal. In type 4 fusion, MB and DB canals were completely fused in 4 of 21 specimens and showed Vertucci type VI, II, I and III configurations. In the remaining 17 samples, MB had Vertucci type I, II, IV, V, VI, VII configurations, while DB showed type I, V and III configurations. In 7 samples with type 5 fusion all canals displayed different configurations. In type 6 fusion, the canal configurations of 6 samples could not be classified. Type II, I, and V configurations were seen in 9 of the remaining 19 samples with a single canal.
 Conclusion: Vertucci type I was the dominant canal configuration in the P and DB, however, MB showed much more diverse configurations either independently or when included in fusion.