Quality of root canal treatment performed by undergraduate students using nickel-titanium reciprocating versus hand instruments.

Abstract

To compare the technical quality of root canal treatment (RCT) depending on the incidence of procedural errors performed by undergraduate students using nickel-titanium reciprocating and conventional hand instrumentation techniques, and to assess the impact of case difficulty and localization of the teeth (maxillary or mandibular molars). Dental records and periapical radiographs of molars that were treated with either hand or reciprocating WaveOne (WO) instruments were evaluated retrospectively. The technical quality of RCTs, the incidence of ledge formation, perforation, instrument fracture, overinstrumentation, underfilling, overfilling, inadequate root canal filling, and the effects of case difficulty and tooth localization were compared using the chi-square test with a significance of 5% (α=0.05). While overinstrumentation was more frequent in the WO group (247 teeth), the incidence of inadequate root canal fillings was higher in the hand instrumentation group (245 teeth) (p<0.01). No significant difference was observed in the incidence of other procedural errors (p>0.05). The number of teeth with acceptable technical quality in preparation and obturation was 172 (69.6%) in the WO group, whereas it was 142 (58%) in the hand instrumentation group, presenting a significant difference between the instrumentation techniques (p<0.01). Higher technical quality rates were observed with WO instrumentation in the high difficulty category and in maxillary teeth (p<0.01). Higher technical quality in preparation and obturation can be achieved with WO reciprocating instruments and file-matched greater tapered gutta-percha cones. No significant difference was observed between the groups in the incidence of procedural errors except for overinstrumentation and insufficient root canal filling. WO instrumentation and obturation with file-matched greater tapered gutta-percha cones provided better technical quality in the high difficulty category and in maxillary teeth.