Histopathologic comparison of periapical inflammation between conventional and profile rotary instrumentation in cat

The purpose of this study was to evaluate and compare the histopathological inflammation of the periapex following preparation of the root canal with conventional and profile rotary instrumentation in cat's teeth. Methods & Materials: In this experimental study, thirty mature healthy cat were used. One canine was used as a negative control for every cat and three residual teeth were prepared with one of the following techniques of instrumentation: (1) step – back by using S-S K-type files, (2) crown down by using Ni-Ti files (3) by profile GT rotary system at 150 rpm speed. Vital animals were perfused at intervals 8, 24 & 48 hours after instrumentation. The canine teeth were separated from the jaws with some of the supporting structures. Then, decalcification and the laboratory processing was done. After obtaining data, they were analyzed with Kruskal Wallis test. 1) The infiltration of inflammatory cells and infiltration of inflammatory cells into the bone marrow was increased by passing the time and maximum infiltration was in 48 hour interval (P<0.05). 2) Although the amount of infiltration of inflammatory cells, edema, vasodilatation and infiltration of inflammatory cells to the bone marrow spaces in the groups of profile and crown – done were less than step – back but they didnt show significant statistically difference. Periapical inflammation in vital teeth without periapical pathosis was not statistically different following various methods of instrumentation.