•Purpose: to provide clinical data on the presence of the second canal in extracted mandibular incisor teeth of Saudi Arabian Samples.
•N= 80 freshly extracted mandibular incisors (40 central and 40 lateral)
•The teeth were accessed by small round bur then placed in 5.25% sodium hypochlorite for 24 hours to dissolve the organic debris.
•Indian ink was injected inside the root canal systems under negative pressure.
•The teeth were decalcified in 5% nitric acid for three days then dehydrated in different concentrations of ethyl alcohol.
•Following the decalcification process, the teeth were cleared in methyl salicylate and evaluated according to first four types of Vertucci’s classification.
Most highlighted Results:
•(70%) of both mandibular central and lateral incisor teeth had type I canal configuration (one main canal and one main apical foramen)
•30% of the sample had a type III canal configuration (two separate canals and merged into one canal before exiting the tooth through single apical foramen).
•The incidence of two canals in mandibular incisor teeth is about one third of the examined Saudi Arabian samples with no difference between the centrals and laterals.
•The clinician should deal with these teeth as if they have two canals unless it is proved otherwise.