Determining the setting of root canal sealers using an in vivo animal experimental model.

Abstract

To present and explore the potential of an animal-based experimental model developed to determine the set of root canal sealers in vivo. The setting of AH Plus, BioC Sealer, TotalFill BC Sealer, and Sealapex was determined using either ISO 6876 or the novel in vivo method proposed in this study. The in vitro setting time of the sealers tested was determined in accordance with ISO 6876:2012. In determining the in vivo set, 24 adult Wistar rats were followed up for two evaluation periods: 1 and 4 weeks. Their upper-right incisor was extracted, and its pulp tissue was removed. The root canal was then filled from retrograde with one of the 4 sealers, and the tooth was re-implanted and fixed with a layer of a flowable composite resin. After 1 or 4 weeks of the surgical procedures, the animals were euthanized, and their incisors were extracted. Two-mm-thick slices of the middle third of the tooth root were obtained and assessed with a Gillmore device, to determine whether or not the sealer had set. The following in vitro results were obtained by using ISO 6876 methodology: AH Plus set after a mean time of 423 ± 20 min and 476 ± 35 min, in metal and plaster molds, respectively. BioC Sealer set after 7 days (in dental plaster molds), whereas TotalFill BC Sealer and Sealapex did not set even after 25 days in both tested conditions (metal or dental plaster molds). Using the novel in vivo methodology, AH Plus, BioC Sealer, and TotalFill BC Sealer set after both 7 and 30 days. In contrast, Sealapex did not set at either time point. AH Plus and BioC Sealer set under both in vitro and in vivo test conditions. TotalFill BC Sealer did not set under in vitro conditions but did after 1 week under in vivo conditions. Sealapex did not set under either in vitro or in vivo conditions. The influence of the testing conditions on the setting results is a clear indication that new in vivo experimental models should be useful in future studies on Bioceramics root canal sealers.