The sample comprised artificial deciduous teeth with coronary and root pulp (Denarte, São Paulo, SP, Brazil) divided into three groups: group I was instrumented with a manual technique (G1), group II used a roundabout technique (G2), and group III used a reciprocating instrumented technique (G3). The manual instrumentation group used instrumentation techniques such as the scheduling Crown–Down manual, which were performed with the Kerr type files 1st series 21 mm (VDW, Munich, Germany). The instrumentation system used the RECIPROC file Reciproc 25/0.08 (VDW, Munich, Germany), while the instrumentation group's rotary system used the Mtwo files of sizes 10/0.4, 15/0.5, 20/0.6, 25/0.6–21 mm, adapted to the VDW engine (VDW, Munich, Germany).
The procedure to gain access to the root canal was performed by an endodontist, experienced in crown opening with a round bur no. 1014, exploitation of channels C file—Pilot # 10 0.2, 21 mm, to the working length (CT) without resistance, and widening the entrance of the conduits with Gates Glidden drills using no. 2–4. It was then performed at timed instrumentation conduits. We used a stopwatch to measure the instrumentation time in each root canal.
The procedure to gain access to the root canal was performed by an endodontist, experienced in crown opening with a round bur no. 1014, exploitation of channels C file—Pilot # 10 0.2, 21 mm, to the working length (CT) without resistance, and widening the entrance of the conduits with Gates Glidden drills using no. 2–4. It was then performed at timed instrumentation conduits. We used a stopwatch to measure the instrumentation time in each root canal.