ALEXANDRU ANDREI ILIESCU, ANCA MELIAN, IONEL DAN-CRISTIAN, CRISTINA STEFANESCU, DIANA MARIA ANTON, GABRIELA POPA, MIHAELA SALCEANU, CRISTINA IORDACHE, MARIUS MANOLE THE EFFICIENCY AND DEGREE OF PENETRABILITY OF FREQUENT WASHING SOLUTIONS USED IN ENDODONTAL TREATMENT The new directions of contemporary endodontics to the evolution of treatment techniques are: CTCB, digital radiography, operating microscope, apex locators, titanium nickel rotation tools and rotating systems that allow them to be used, special endodontic irrigation means, use of ultrasonic means, laser applications. The success rate of nowadays endodontic treatments based on the principles accepted and adopted so far should be rather high. However, there are studies that indicate a fairly low percentage of fully successful endodontic treatments. The main causes for which these data are recorded are various, some are strictly the dentist’s technique and some are related to the patient’s field. Obviously, there is a contradiction between what can be achieved and the final result. The study includes a batch of 52 teeth pluriradicular as well as monoradiculars considered irrecoverable and extracted due to clinical situations requiring this method of treatment. Anatomy of dental canals is an important factor to be considered in the irrigation efficiency of the apical region; the degree of permeability of dentinal canals in this area is poor due to very small diameters, cumulative factors can lead for sure to a failure of endodontic treatment. In the coronal and media regions of the channels, the effectiveness of the lavage solutions used could be assessed. These very good results were in accordance with the studies performed and presented.