In Situ Assessment of the Setting of Tricalcium Silicate–based Sealers Using a Dentin Pressure Model

• EndoSequence BC sealer is a premixed root canal sealer that sets when in contact with dentinal fluid; thus, its setting cannot be monitored in vitro.
• Calcium silicate–based root canal sealers are bioactive after hydration and contact with tissue fluids.
• The fluid pressure setup is a reliable method to assess the setting characteristics of sealers in vitro. Immersion of materials in solution does not mimic the clinical scenario.
• The dentinal fluid present in the root canal is adequate to allow EndoSequence BC Sealer to set inside the root canal.

IntroductionEndoSequence BC Sealer (Brasseler, Savannah, GA) is a premixed tricalcium silicate–based root canal sealer that requires moisture from the root dentin to hydrate. The aim of this study was to investigate the setting of EndoSequence BC Sealer and other sealers in contact with human dentin in a simulated clinical environment.MethodsEndoSequence BC Sealer, MTA Fillapex (Angelus, Londrina, Brazil), Septodont Sealer (Septodont, Saint Maur-des-Fosses, France), and Apexit Plus (Ivoclar, Schaan, Lichtenstein) were assessed. Caries-free lower premolars extracted for orthodontic purposes in patients aged 13–16 years were standardized to a 10-mm root length and were filled with test sealers and set up in a dentin pressure model for 14 days. In addition, set sealers immersed in physiologic solution for 14 days were also assessed. The set materials in solution and materials retrieved from the dentin pressure setup were characterized by scanning electron microscopy and X-ray diffraction analysis. The setting time and radiopacity were assessed using ISO 6876:2002 specifications. Furthermore, mineral ion leaching was evaluated by inductively coupled plasma mass spectrometry.ResultsAll the sealers tested exhibited formation of a calcium phosphate phase when in contact with physiologic solution. Septodont Sealer and Apexit Plus did not exhibit the formation of a calcium phosphate phase in the dentin pressure setup. The fluid in the system was enough to allow the setting of EndoSequence BC Sealer, which did not set in a dry environment. All materials leached calcium with the Septodont Sealer, exhibiting double the calcium ion leaching compared with EndoSequence BC Sealer.ConclusionsUsing the dentinal fluid pressure system resulted in an adequate flow of dentinal fluid that allowed EndoSequence BC Sealer to set inside the root canal. Although the sealers tested were tricalcium silicate based, the hydration reaction and bioactivity in the presence of dentinal fluid were different to hydration in vitro. Thus, clinically, material bioactivity cannot be assumed.