[Cleanliness of the walls of root canals in teeth with incomplete development of root, rinsed with 2% chlorexidine. A SEM study].

INTRODUCTION The aim of the study was to evaluate the cleanliness of the walls of root canals with incomplete development of root, whose lumen was rinsed with 2% chlorhexidine solution during mechanical preparation. MATERIAL AND METHODS Use was made of 8 maxillary premolar teeth with a single root canal and with incomplete development of the root apex (the teeth were removed during the growing stage for orthodontic reasons). The coronal and middle parts of the canals were instrumented using Gates-Glidden no. 3 and 4 drills, and the apical section with the help of Hedstroem size 50-80 files. During instrumentation of the canals irrigation was carried out using 2% chlorhexidine solution. Irrigating solution, volume 2 mL, was introduced into the canal with the use of a syringe and an endodontic needle after using each instrument, and 5 mL volume after complete instrumentation of the canal. RESULTS Observations using a scanning electron microscope with x200 and x1000 magnification showed relatively effective removal of pulp remains and dentine chips, and the presence of a thick smear layer covering the canal walls throughout their length. Statistical analysis did not show significant differences in the degree of cleaning of particular sections of the canals. CONCLUSION The presence of the smear layer in canals irrigated with chlorhexidine is evidence that it does not have properties for it to be dissolved, and this dictates the necessity of using chelating agents.