comparative evaluation of effi cacy of endovac irrigation system to max-i probe in removing smear layer in apical 1 mm and 3 mm of root canal: an in vitro scanning electron microscope study

background: the purpose of this study was to compare the effi cacy of endovac irrigation system and side-vented closed ended needle (max-i probe) in removing smear layer from root canals at 1 mm and 3 mm from working length using protaper rotary instrumentation. materials and methods: a total of 50 freshly extracted maxillary central incisors were randomly divided into two groups after complete cleaning and shaping with protaper rotary fi les. in one group, fi nal irrigation was performed with endovac system while in other group, fi nal irrigation was done with a 30 gauge max-i probe. 3% sodium hypochlorite (naocl) and 17% ethylenediaminetetracetic acid were used as fi nal irrigants in all teeth. during instrumentation, 1 ml of 3% naocl was used for irrigation after each rotary instrument in the similar manner as in fi nal irrigation. after instrumentation and irrigation, teeth were sectioned longitudinally into buccal and palatal halves and viewed under scanning electron microscope for evaluation of smear layer. statistical analysis was performed using kruskal-wallis and mann-whitney u-test. ( p < 0.05) results: at 3 mm level, there was no signifi cant difference between two groups. at 1 mm level, endovac group showed signifi cantly better smear layer removal compared with max-i probe ( p = 0.0001). conclusion: endovac system results in better smear layer removal at 1 mm from working length when compared to max-i probe irrigation. key words: endovac, max-i probe, root canal irrigation, scanning electron microscope,smear layer