Regaining apical patency after obturation with gutta-percha and a sealer containing mineral trioxide aggregate.

INTRODUCTION: MTA Fillapex (Angelus Solucoes Odontologicas, Londrina PR, Brazil) was introduced as a mineral trioxide aggregate (MTA)-based sealer used for endodontic obturation. There is a lack of research that evaluates the ability of different solvents to soften MTA-based sealers during retreatment. This study tested the ability of 4 commonly used endodontic solvents to soften gutta-percha and MTA Fillapex to allow for the re-establishment of apical patency. METHODS: Eighty-six extracted maxillary anterior teeth were instrumented to the working length to a size 45 (.04 taper size). Teeth were divided into 2 groups (n = 43 for each group). MTA Fillapex was placed into all canals. Group 1 was obturated with gutta-percha to the working length, and group 2 was obturated 2 mm short of the working length to ensure the apical 2 mm was filled with sealer only. Both groups were divided into 4 subgroups (n = 10). The remaining teeth served as the control group. Each subgroup was exposed to 1 of the following solvents: chloroform, Endosolv R (Septodont, Saint-Maur, France), Endosolv E (Septodont), or eucalyptol. RESULTS: Patency was re-established in 100% of the teeth in groups 1 and 2 when tested with chloroform or Endosolv E, 80% of the teeth in group 1 and 90% in group 2 when tested with eucalyptol, and 10% of the teeth in group 1 and 50% in group 2 tested when with Endosolv R. The chi-square test indicated there was a statistical difference between Endosolv R and the other tested solvents for both groups. CONCLUSIONS: Chloroform, Endosolv E, and Eucalyptol soften GP and MTA Fillapex sufficiently to aid in re-establishing apical patency during endodontic retreatment.

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(4)OH 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.