In vitro comparative study of some filling materials ability on retrograde apical sealing

ABSTRACT

Background and Aim: Application of a retrograde filling material in a cavity prepared in root-end through endodontic surgery has great importance to provide apical seal and prevent bacterial penetration. Therefore, The aim of this in vitro study was to compare the sealability of Gray-colored Portland Cement [GPC], White-colored Mineral Trioxide Aggregate [WMTA], and [Sealapex] with addition of Zinc Oxide [ZnO] when used as retrograde filling materials to investigate which of these materials has the best apical sealability. Materials and Methods: The sample of study consisted of sixty recently extracted, single-rooted, permanent human teeth. The root canals were prepared using Crown-Down technique and obturated with laterally condensed gutta-percha points and zinc oxide-eugenol sealer, then the coronal restorative material [GIC] was placed. After that, [2-3 mm] of each root apex was sectioned at 45° angle, the apical cavities with the depth of [2-3 mm] were performed for the retrograde filling, then the sample was randomly divided into 3 equal groups of 20 teeth each, according to the retrograde filling material used /[Group1 [GPC], Group2 [WMTA], Group3 [Sealapex + ZnO]/]. After retrograde filling, the apical sealability was assessed by immersion in 2% methylene blue dye [100% humidity at 37°C] for 24 hours. The teeth were sectioned longitudinally in a buccolingual direction, then the extent of dye penetration was examined by a stereomicroscope [20X magnification]. Results: Kruskal-Wallis, one-way ANOVA, and Bonferroni tests were used, it showed that [WMTA] was the best retrograde filling material as an apical sealing [P<0.05] material. There was a statistically significant difference in the mean of apical dye leakage between [WMTA] and [GPC]. The next material was [Sealapex + ZnO], but there was no statistically significant difference in the mean of apical dye leakage between it and [WMTA]. The last material was [GPC], but also there was no statistically significant difference in the mean of apical dye leakage between it and [Sealapex + ZnO]. Conclusions: [WMTA] is a promising material as an apical sealing material used in retrograde filling, it has an apical sealability better than other materials used in this study, and [GPC] can not be used in a retrograde filling. KeyWords Apical sealability, Retrograde filling, PC, MTA, Sealapex