Efficiency of Supplementary Contemporary Single-file Systems in Removing Filling Remnants from Oval-shaped Canals: An In Vitro Study

Abstract

This study investigated the performance of supplementary three single-file systems for eliminating root filling residue from oval-shaped canals utilizing cone-beam computed tomography (CBCT). Thirty single-rooted human mandibular premolars with oval-shaped canals were chosen. After decoronation and working length determination, ProTaper Universal (PTUR) rotary files were used to prepare canals up to F3. Irrigation was fulfilled by 2.5% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA), and lastly distilled water. By utilizing the lateral compaction technique, canals were filled by gutta-percha and Endosequence BC Sealer. The PTUR retreatment system (D1, D2, and D3) eliminated the primary filling material sequentially. Subsequently, specimens were categorized into three groups at random: group I: WaveOne Gold (WOG) primary file, group II: TruNatomy (TRN) medium file, and group III: XP-endo Finisher R (XPF-R). The volume of residual left from filling material was quantified utilizing CBCT imaging before and after the supplementary retreatment. Statistical analyses were done by one-way analysis of variance (ANOVA) and Tukey's test at a 5% significance level. The volume of removed root filling after using XPF-R was significantly higher than using WOG in all sections and TRN in the coronal third, while nonsignificantly higher than using TRN in the apical and middle. XPF-R as a supplementary technique revealed the highest percentage reduction of root filling material (73.13%) in comparison with the other systems (37.39% WOG and 44.16% TRN) in oval-shaped canals. Neither one of the methods and tools used to remove filling material from oval-shaped root canals is perfectly efficient. The performance of supplementary techniques using contemporary single-file systems improves the cleaning and reshaping of root canal space that permits a proper disinfection to optimize the outcome of retreatment option.