Abstract
Background and objective: As a cause of treatment failures, lack of a working knowledge of pulp anatomy ranks second only to errors in diagnosis and treatment planning. The purpose of this study was to investigate variations in the root canal system of maxillary first and second permanent premolar teeth.
Materials and Methods: In this study, 188 maxillary first premolars and 138 second premolars, after access cavity preparation, the teeth were decalcified by 5% Nitric acid, dehydrated, cleared using Methyl salysilate, dye-injected and studied.
Results: The results showed that 6.38% of maxillary first premolars had one canal, 90.43% had two canals and 3.19% had three canals, and also 50% of maxillary second premolars had one canal and 50% had two canals.
Conclusion: The first and second maxillary premolars should always be considered as having two root canals, unless Other wist is Proved, and also first maxillary premolars with three canals should be considered.