[Upper premolars: study of the number of roots and their canals].

The number of roots and cannals were observed and studied in upper bicuspids. For the study of the root cannals was used a diafanization technique. The results were prosessed by stadistic analysis and compared with those published. By the observation, in this work, was stated that the first upper bicuspid has one root and two cannals in the most of the cases. This situation was confirmed by stadistic analysis. Conclusions were extracted refering them to the clinical application.