Objective:The complete filling material removal during endodontic retreatment is a clinical procedure difficult to achieve. The aim of this study was to evaluate the efficacy of reciprocating and continuous rotary nickel-titanium instruments used in root canal retreatment.Materials and Methods:Forty freshly extracted human premolars were cleaned and shaped by the crown-down technique, followed by filling by the lateral compaction technique. The teeth were randomly separated into two groups (n = 20), according to the system used for filling material removal: G1 - Reciproc and G2 - ProTaper Universal Retreatment System. The teeth were photographed under operating microscope at ×8 magnification; and the total area of the root canal and remaining filling material were quantified.Results:No statistically significant difference (P > 0.05) in residual filling material was observed between groups; however, the time required for filling removal was significantly shorter for Reciproc system (P < 0.05).Conclusions:It was observed remaining filling material in all teeth, irrespective of the system used; however, root canal retreatment was faster when reciprocating motion was used.

The cleaning capacity of hybrid and rotary instrumentation techniques in mesial flattened canals of mandibular first molars was evaluated by morphometrical analysis in this study. Twenty human mandibular first molars were randomly assigned into two groups, according to instrumentation technique, as follows: group 1, instrumentation with ProTaper Starter Kit (Dentsply/Maillefer) rotary system; group 2, manual instrumentation using K files (Dentsply/Maillefer) by crown-down technique in middle and apical thirds, cervical preparation with Gates-Glidden #1 and #2 (Dentsply/Maillefer) burs, and to finalise the preparation, ProTaper F2 and F3 rotary files. Serial transverse cross-sections (5 µm) of the apical third, stained with hematoxylin and eosin, were analysed at 100× original magnification. The images were submitted to morphometrical analysis with an integration grid to determine the percentage of root canal area with debris. Statiscal analysis (t-Student, P < 0.05) showed significant difference between the techniques (P < 0.05), although neither completely cleaned the root canal.

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The axial displacement of a tooth within the alveolar bone is called traumatic intrusive luxation. The treatment of immature permanent teeth with incomplete root formation is a challenging procedure, as the prognosis is uncertain. The objective of the present article is to report the successful treatment of traumatic intrusive luxation in teeth with incomplete root formation, where mineral trioxide aggregate (MTA) was used as an apical plug to induce apexification. A 10-year-old boy was referred to our department for emergency treatment of dentoalveolar trauma to the maxillary central incisors. After clinical and radiographic examination, the teeth were surgically repositioned and rigidly fixed. Three months later, a pulp vitality test of both teeth elicited a negative response. Endodontic therapy with an MTA plug was used to induce apexification as root formation was incomplete. The root canals were then filled. Clinical and radiographic examination was then performed again at 2 and 4 months later. The MTA apical plug was effective in inducing apexification and maintaining both teeth.