C-shaped Root Canal Prevalence and Configurations in Egyptians

1. Scientific Background: The main goal of conventional root canal treatment is to prevent or heal apical periodontitis through cleaning, shaping and three-dimensional obturation of the root canal system. To establish this goal; recognition of root canal anatomy is required to minimize the risk of treatment failure. Studies recorded variations among different ethnicities in the prevalence and configurations of some root canal systems in particular interest is the root canal configurations of the mandibular first and second molars. Anatomical variations recorded include radix entomolaris, radix paramolaris and C-shaped canal. The prevalence of C-shaped root canal ranges between 2.6% to 44.5% among different ethnicities with the highest percentage in Asian populations. C-shaped root canal anatomy has challenges in the diagnosis and endodontic management. Challenge in diagnosis is attributed to the variations in the root canal anatomy that may extend along the entire length of the canal. Preoperative identification of C-shaped root canal and its configurations is difficult by conventional radiographic techniques due to their inherent limitations. Challenges in endodontic management are attributed to the presence of complex isthmi, fins and webs connecting the individual root canals that may complicate the proper cleaning and shaping of the root canal rendering it more difficult. Therefore, it is important to detect and identify the configuration of C-shaped canals before root canal treatment. Preoperative recognition of the prevalence and root canal configurations will direct the attention of endodontists to its presence and will facilitate the root canal accessing, negotiation, determining the best three-dimensional instrumentation and obturation technique.
2. Rationale of the study:

Different methods have been used to investigate the prevalence and configurations of C-shaped root canal including: microscopic examination of extracted demineralized teeth after black ink infiltration or microscopic examination for polyester cast resin of the pulp space of demineralized extracted teeth or microscopic examination of extracted teeth with methylene blue dye infiltration followed by resin imbibition, conventional radiography, medical CT and most recently CBCT.

CBCT was reported to be accurate for various root canals morphological analysis because of the 3-dimensional reconstruction of the internal and external morphology of the tooth and high spatial resolution in all planes. It has the ability to investigate the morphology of the root canal system without intervention. Compared to medical CT, CBCT can be accomplished with a substantially lower effective dose and reduced acquisition time.

According to my knowledge, there is only one study that has investigated the prevalence of the C-shaped root canal in mandibular first and second molars among members of sub-Egyptian population, but the configurations of C-shaped root canal have not been studied yet.

Knowledge of the prevalence rate and root canal configurations will direct the attention of endodontists to its presence and will facilitate the root canal accessing, negotiation, determining the best instrumentation and obturation technique thus, long term success rate of the endodontic therapy.