title: Physical properties of 5 root canal sealers.
abstract: BACKGROUND
  The aim of this study was to evaluate the pH change, viscosity and other physical properties of 2 novel root canal sealers (MTA Fillapex and Endosequence BC) in comparison with 2 epoxy resin-based sealers (AH Plus and ThermaSeal), a silicone-based sealer (GuttaFlow), and a zinc oxide-eugenol-based sealer (Pulp Canal Sealer).
  
  
  METHODS
  ISO 6876/2001 specifications were followed. The pH change of freshly mixed and set sealers was evaluated during periods of 1 day and 5 weeks, respectively. The viscosity was investigated at different injection rates (72, 10, and 5 mm/min) at room temperature by using a syringe-based system that was based on the Instron 3360 series universal testing system.
  
  
  RESULTS
  The flow, dimensional change, solubility, and film thickness of all the tested sealers were in agreement with ISO 6876/2001 recommendations. The MTA Fillapex sealer exhibited a higher flow than the Endosequence BC sealer (P < .05). The MTA Fillapex and Endosequence BC sealers showed the highest film thicknesses among the tested samples. The Endosequence BC sealer exhibited the highest value of solubility, which was in accordance with 3% mass fraction recommended by the ISO 6876/2001, and showed an acceptable dimensional change. The MTA Fillapex and Endosequence BC sealers presented an alkaline pH at all times. The pH of fresh samples of the AH Plus and ThermaSeal sealers was alkaline at first but decreased significantly after 24 hours. The viscosity of the tested sealers increased with the decreased injection rates.
  
  
  CONCLUSIONS
  The tested sealers were pseudoplastic according to their viscosities as determined in this study. The MTA Fillapex and Endosequence BC sealers each possessed comparable flow and dimensional stability but higher film thickness and solubility than the other sealers tested.
authors.affiliation: Center for Biomedical Materials and Engineering, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin, China; Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Hui-min
authors.initials: HM
authors.lastname: Zhou
authors.forename: Ya
authors.initials: Y
authors.lastname: Shen
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Yu-feng
authors.initials: YF
authors.lastname: Zheng
authors.forename: Markus
authors.initials: M
authors.lastname: Haapasalo
mesh_terms: D000468:Alkalies / Q000737:chemistry; D017607:Aluminum Compounds / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D055598:Chemical Phenomena; D003799:Dental Stress Analysis / Q000295:instrumentation; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004338:Drug Combinations; D004853:Epoxy Resins / Q000737:chemistry; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D010087:Oxides / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry; D012995:Solubility; D013499:Surface Properties; D013594:Syringes; D013696:Temperature; D013997:Time Factors; D014783:Viscosity; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
chemical_list: D000468:Alkalies; D017607:Aluminum Compounds; D017610:Calcium Compounds; D002130:Calcium Phosphates; D004129:Dimethylpolysiloxanes; D004338:Drug Combinations; C550603:EndoSequence root repair material; D004853:Epoxy Resins; C515718:GuttaFlow; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C089258:Thermaseal Silverfree; D015035:Zinc Oxide-Eugenol Cement; C534916:epoxy resin-based root canal sealer; C086631:mineral trioxide aggregate; D006171:Gutta-Percha
keywords: Flow; pH change; physical properties; root canal cements; tricalcium silicate sealer; viscosity