Análise comparativa da ação dos instrumentos rotatórios ou reciprocantes no retratamento endodôntico

Abstract

This study evaluated the ability of instruments to centralize, formation of apical deviation, percentage increase of root canal, amount of remaining filling material and increase of root canal diameter after retreatment and reinstrumentation protocols with mechanized instruments. The 54 mesial roots of mandibular molars were instrumented, obturated and randomly divided into three experimental groups: WOG (Primary and Medium), PTN (X2 and X3) and PTU (F2 and F3) groups. In each group, one instrument was used to remove the filling material and another instrument was used for reinstrumentation. The images generated after each step (initial instrumentation, obturation, removal of the filling material and reinstrumentation) were analyzed in 1o mm, 3o mm and 5o mm apical roots and a statistical analysis of the data was performed. The results did not show full capacity of centralization of the studied instruments (= 1.0). Statistically, PTN presented greater apical deviation at 5o mm in relation to WOG. After reinstrumentation, the WOG system showed a greater area increase at 1o and 5o mm apical in relation to PTN and PTU. The increase in diameter evaluated by x ray, the WOG system was statistically more satisfactory than PTN after removal of the filling material. After reinstrumentation, WOG was statistically more significant than the PTN and PTU groups. There was no statistically significant difference between the groups in the remaining filling material count. It was concluded that the WOG system was an alternative to be used in cases of endodontic retreatment.