Canal and isthmus debridement efficacy of the VPro endosafe negative-pressure irrigation technique

Introduction: This study compared canal and isthmus debridement efficacies between side-vented needle irrigation (SNI) and the VPro EndoSafe (VPro) negative-pressure device (Vista Dental, Racine, WI) in mesial roots of mandibular first molars with narrow isthmuses in a closed-canal design. Methods: Twenty teeth with narrow isthmuses were selected using micro-computed tomography scanning. Collagen solution was reconstituted with 1% NH ₄OH to simulate debris and injected into canals via vacuum. Canals were instrumented to size 40/.04. Final irrigation was performed with 17% EDTA and 6% NaOCl using SNI with a 30-G needle or the VPro system. Roots were demineralized, and Masson trichrome-stained sections were prepared at 1.2 to 3.2 mm from the anatomic apex for a total of 6 canal levels. Debris-filled areas within the canals and isthmuses were measured using ImageJ software (National Institutes of Health, Bethesda, MD) and statistically analyzed using repeated-measures analysis. Results: There was no significant difference between techniques and debridement efficacy among the 6 levels within the canal (P =.108). The debridement efficacy at 1.6 mm differed significantly from that at 3.2 mm. VPro had significantly more debris at isthmus levels 2.0 and 2.4 mm than SNI (P =.009). A significant difference was observed between the canal and the isthmus (P <.001). Neither VPro nor SNI removed debris completely from the apical third or isthmus. Conclusions: VPro EndoSafe did not differ significantly from SNI in the overall debridement efficacy in the apical third of mesial roots of mandibular first molars.