Comparação da infiltração apical entre a desobturação imediata do canal radicular e a desobturação após 8 dias para a preparação do espaço para o espigão

Introduction: The success of endodontically treated teeth may be influenced by the ability to maintain the integrity of the apical seal. Objective: To compare the apical leakage in teeth where post space preparation was made immediately after root filling, with delayed post space preparation (8 days after). Materials and Methods: A total of 40 recently extracted human teeth with single root canal, were prepared using step-back technique. The teeth were randomly divided into four groups: 17 teeth in groups I and II and 3 teeth in each of the groups III and IV (controls). In groups I and II the teeth were filled with gutta- -percha and zinc oxide-eugenol sealer by the lateral condensation technique. In group I the post space was made immediately at the time of obturation. In group II the post space was made 8 days after the root filling. ProTaper Universal retreatment files were used for post space preparation. In groups I and II the teeth were covered with fingernail polish except for the last 2mm. In group III the teeth were not obturated (positive control). In group IV the teeth were covered all over the root surface with fingernail polish (negative control). The methylene-blue dye method was used to measure the apical leakage. Results: Teeth whose post space preparation was made immediately had a mean distance of 1,23 mm of apical leakage (group I), whereas teeth that had been prepared 8 days after had a mean distance of 2,36 mm of apical leakage (group II), being the differences statistically significant (p<0,05). Conclusions: The timing for post space preparation may conditionate the apical leakage.