The aim of study was to check the application of a new x-ray contrast hollow waveguide which is suitable for x-ray diagnostics and treatment required in endodontics. Er:YAG and Alexandrie laser system generating a wavelength of 2940 nm and 375 nm were used. The root canals of 10 teeth were treated endodontically and result of that treatment was compared with the common cleaning methods. During the treatment the x-ray images were taken with conventional files and using this new design hollow waveguide. After laser therapy the teeth were cut in a longitudinal axis and viewed using the scanning electron microscope. It was demonstrated that no differences exist between of x-ray opacity of the metal instrument used for the endodontic treatment and the special hollow waveguide. In SEM the open dentinal tubules were visible. No cracks were determined. A smear layer was removed. The surface modification after laser treatment was not found.

        Key words: dentistry – laser – endodontics