title: A comparative study of selected physical properties of five root-canal sealers.
abstract: OBJECTIVE
  To investigate selected physical properties of five root-canal sealers.
  
  
  METHODS
  The solubility, film thickness, flow, working and setting times of Roth 801, Tubli-Seal EWT, AH Plus, Apexit and Endion were evaluated. Solubility was measured by weight change of standard specimens in water over a 3-month period. Film thickness was measured as the distance between weighted glass slides containing a standard quantity of sealer. Flow was assessed by rate of sealer extrusion through a standard bore diameter, after unit time. Working time was taken as the point at which flow rate was reduced by 10%. The indentation test using a modified Gilmore needle was employed to investigate the setting times.
  
  
  RESULTS
  AH Plus was the least soluble, whilst Apexit was the most unstable in water. The solubility values in increasing order were: AH Plus<Tubli-Seal EWT<Endion<Apexit. Also, AH Plus had the highest film thickness. All sealers showed comparable flow rates. The working time varied from 50 min for Endion to over 2 h for AH Plus and Tubli-Seal EWT. The range of setting times recorded was from 70 min for Tubli-Seal EWT to 8 days for Roth 801.
  
  
  CONCLUSIONS
  1. AH Plus showed the greatest stability in solution and Tubli-Seal EWT performed well, but Apexit and Endion had higher solubility values. 2. The film thickness values in increasing order were: Tubli-Seal EWT<Apexit<Endion=Roth 801<AH Plus. 3. The flow rates for all sealers were similar. 4. The working times for all sealers were greater than 50 min. 5. Roth 801 did not set when incubated in volumes sufficient to fill the test matrices.
authors.affiliation: Department of Conservative Dentistry, Eastman Dental Institute for Oral Health Care Sciences, University College London, London, UK.
authors.forename: F R S
authors.initials: FR
authors.lastname: McMichen
authors.forename: G
authors.initials: G
authors.lastname: Pearson
authors.forename: S
authors.initials: S
authors.lastname: Rahbaran
authors.forename: K
authors.initials: K
authors.lastname: Gulabivala
mesh_terms: D002126:Calcium Hydroxide / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004853:Epoxy Resins / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D012212:Rheology; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D013997:Time Factors; D014783:Viscosity; D014867:Water / Q000737:chemistry; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
chemical_list: C074418:Apexit; C098488:Endion; D004853:Epoxy Resins; D005899:Glass Ionomer Cements; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C534916:epoxy resin-based root canal sealer; D014867:Water; C074935:Roth's 801 Sealer; C048769:tubliseal; D002126:Calcium Hydroxide