Avaliação da eficácia da instrumentação manual x automatizada durante o retratamento endodôntico em canais radiculares obturados com guta-percha e cimento à base de hidróxido de cálcio

The aim of this study was to evaluate the effectiveness of the manual and mechanized instrumentation at gutta-percha and calcium hydroxide-based sealer removal from root canals. Thirty palatal roots of upper molars were, ex vivo, evaluated about the effectiveness of manual stainless-steel and rotary nickel titanium (ProTaper Universal, Dentsply-Maillefer, Ballaigues) instruments on desobturation and reinstrumentation of root canals filled with gutta-percha and calcium hydroxide-based sealer (Sealapex, Sbron Endo). Roots were then sectioned, the remaining filling material inspected under operatory microscope and photographed by digital camera. The AUTOCAD 2004 program measured and calculated remaining filling material by thirds and total root canal area. For the manual technique the Kruskal-Wallis test didn’t revealed difference between cervical, medium and apical thirds (P=0.253). For rotary technique the Kruskal-Wallis test revealed statistically significant difference between cervical, medium and apical thirds (P<0.0001). The 5% Tukey’s test identified higher amount of filling material on the apical third than cervical and medium. Using rotary technique more filling materials remains at the apical portion. Both groups showed filling material remaining on 3 thirds. Keywords: endodontics, retreatment, root canal obturation