Non-instrumentation Root Canal Treatment of Primary Molars

This randomized clinical trial intended to evaluate the efficacy of a technique of root canal treatment of deciduous molars with non-instrumentation of root canals and use of a paste containing antibiotics (chloramphenicol and tetracycline) and zinc oxide and eugenol (CTZ group). The hypothesis is that the efficacy of non-instrumentation treatment is non-inferior than the standard treatment involving manual instrumentation of root canals and filling with zinc oxide and eugenol paste (ZOE group) after 24 months of follow-up. Children will be randomly allocated to one of the two groups: CTZ group or ZOE group. In the CTZ group, after the location of root canals entrance, an initial irrigation will be conducted using 1% sodium hypochlorite. Then, CTZ paste will be placed in the pulp chamber floor, over the root canal entrances. The instrumentation of the root canals will not be performed for children allocated to this group. For the ZOE group, manual instrumentation with endodontic K files will be performed, aided by irrigation with 1% sodium hypochlorite. After the end of the instrumentation, root canals will be filled with ZOE paste. All teeth will be restored with bulk-fil resin composite. Children will be followed-up for 6, 12, 18 and 24 months after the treatment. The primary endpoint will be the success of endodontic treatment evaluated by clinical and radiographic methods after 24 months. Based on a non-inferiority limit of 15% in the success rate, an anticipated sample size of 218 (109 per group) was estimated, divided among the centers. This sample size was further corrected two times (due to slower-than-anticipated recruitment, and due to the drop of a center participant of the study), reaching a required minimum sample size of 182 participants (91 participants per group). Other secondary endpoints will be clinical time spent with the treatments, children's behavior during the treatment, discomfort immediately after the end of the treatment reported by the c