Abstract
OBJECTIVES: The aim of this study was to compare two teaching protocols according to the technical quality of root canal therapy (RCT) and the procedural errors occurred in preclinical training. MATERIALS AND METHODS: Two different groups of students were concerned. The first one (G1) performed a crown-down technique to shape the root canal systems and cold lateral condensation technique to fill them. The second one (G2) performed a step-down technique without initial manual scouting to shape the root canal systems, and cold hydraulic condensation technique, to fill them. G2 used clinical operative microscope to check the access cavity preparation. STATISTICAL ANALYSIS: The quality of RCTs and procedural errors were recorded and analyzed using chi-squared test and t-test. RESULTS: Four hundred sixty-eight root canals from 152 maxillary molars were treated by the G1 students: 46.6% canals were judged as acceptable. Four hundred sixty-nine root canals from 152 mandibular molars were treated by G1: 58.8% canals were judged as acceptable. Five hundred fifteen root canals from 156 maxillary molars were treated by G2 students: 84.1% canals were judged as acceptable. Four hundred ninety-three root canals from 156 mandibular molars were treated by G2: 90.9% canals were judged as acceptable. Among the errors, the incidence of "ledges" and "fractured instruments" was statistically significant in G1 compared with G2, both on maxillary and on mandibular molars. CONCLUSIONS: The molar RCTs performed by G2, who got benefit from the new teaching protocol, resulted in a better quality of root filling and in fewer procedural errors compared with the molar RCTs performed by G1.