Canal and isthmus debridement efficacy using a sonic irrigation technique in a closed-canal system

Introduction: This in vitro study compared debridement efficacies of a sonic irrigation technique (Vibringe; Cavex Holland BV, Haarlem, The Netherlands) with side-vented needle irrigation (SNI) in the mesiobuccal root of maxillary first molars. Methods: Twenty roots with narrow isthmuses (≤1/4 canal diameter) were selected using micro-computed tomography scanning. Collagen solution was injected into canals/isthmuses and reconstituted with NH ₄OH to simulate canal debris. Each root was sealed apically and embedded in polyvinyl siloxane simulating a closed-canal system. Canals were instrumented to size 40/.04 taper 1 mm short of the anatomic apex. The final irrigation was performed with the Vibringe or SNI. Roots were demineralized, sectioned at 6 levels (1.2-3.2 mm) from the anatomic apex, and stained using Masson trichrome stain. The areas occupied by canals and isthmus and the debris-containing areas were statistically analyzed with repeated-measures analyses using "irrigation technique" as the between factor and "canal level" as the within factor (α = 0.05). Results: Canals had significantly more debris at 1.2 and 1.6 mm (P <.001), but there was no overall difference between the 2 techniques (P =.561). Significant differences were found between the Vibringe and SNI at 2.4, 2.8, and 3.2 mm (P <.05). There was no significant difference in the remaining debris in the isthmus for SNI at all (P > .05). Considerably more debris remained at 1.2 and 2.0 mm for the Vibringe (P <.05). A significant difference was observed between the canal and the isthmus (P <.001). Conclusions: There is no difference between the Vibringe and SNI in their overall debridement efficacy in apical one third of the mesiobuccal root of maxillary first molars.