Efficacy of the non-instrumentation endodontic treatment with CTZ paste in primary molars: Protocol of a multicenter randomized clinical trial with two years of follow-up

Objective: There is a lack of high-quality evidence on the efficacy of the non-instrumentation endodontic treatment (NIET) in primary molars, compared to the conventional endodontic treatment technique. This protocol describes a multicenter randomized clinical trial that aims to evaluate the efficacy of a NIET technique for primary molars using a paste containing antibiotics (chloramphenicol and tetracycline – CTZ group) compared to a control group of conventional technique and root filling with zinc oxide eugenol (ZOE). Methodology: Children aged 3 to 9 years (N=218) will be randomly allocated to one of the groups: CTZ or ZOE. In CTZ, after the location of root canals entrance, irrigation will be performed using 1% sodium hypochlorite and CTZ paste will be placed over the root canal entrances, with no instrumentation of the root canals. In ZOE group, manual instrumentation of root canals with endodontic K-files will be performed, and then, the root canals will be filled with ZOE paste. At the same appointment, teeth will be restored with a double-seal of glass ionomer and a bulk fill resin composite. Children will be followed-up for 6, 12, 18 and 24 months. The primary endpoint will be the success of endodontic treatments evaluated by clinical and radiographic criteria after 24 months. Conclusions: NIET with CTZ paste could be an option to manage primary teeth, once the technique could have non-inferior efficacy to the conventional technique that involves root canal instrumentation. The approach could have good acceptance from children and parents considering the reduced clinical time.