title: A temporary filling material may cause cusp deflection, infractions and fractures in endodontically treated teeth.
abstract: OBJECTIVE
  To test the hypothesis that Coltosol F might cause infractions and cusp fracture in root-filled teeth because of material expansion.
  
  
  METHODS
  Thirty-two extracted human molar teeth were root filled and prepared with mesial-occlusal-distal (MOD) cavities with or without undercuts. The specimens were filled proximally with glass-ionomer cement and then occlusally with either Coltosol F or zinc oxide eugenol (ZOE). The tooth specimens were kept in water at 37 degrees C for a period of 20 days, and every second day the intercusp distance (ICD) of each specimen was measured in a travelling microscope, and the number of infraction lines as well as fractures were noted.
  
  
  RESULTS
  The number of infraction lines increased in teeth filled with Coltosol F. Between day 8 and 16, seven of 16 teeth filled with Coltosol F showed fracture and exhibited a mean increase in ICD of 316 +/- 156 microm. Teeth filled with ZOE did not show an increase in number of infraction lines or in ICD, and none showed fracture.
  
  
  CONCLUSIONS
  The hygroscopic expansion of Coltosol F in a cavity may lead to cusp deflection, infraction development and fracture. Masticatory forces will in vivo aggravate this unfavourable condition. The material is not recommended for temporary filling in root-filled teeth except for a few days.
authors.affiliation: Department of Cariology and Endodontics, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. mhl@odont.ku.dk
authors.forename: M H
authors.initials: MH
authors.lastname: Laustsen
authors.forename: E C
authors.initials: EC
authors.lastname: Munksgaard
authors.forename: C
authors.initials: C
authors.lastname: Reit
authors.forename: L
authors.initials: L
authors.lastname: Bjørndal
mesh_terms: D002133:Calcium Sulfate / Q000009:adverse effects; D003738:Dental Cements / Q000009:adverse effects*; D003794:Dental Restoration, Temporary / Q000009:adverse effects*; D006801:Humans; D008963:Molar; D019228:Tooth Crown / Q000293:injuries; D014082:Tooth Fractures / Q000209:etiology*; D019553:Tooth, Nonvital; D019287:Zinc Sulfate / Q000009:adverse effects
chemical_list: C504942:Coltosol F; D003738:Dental Cements; D019287:Zinc Sulfate; D002133:Calcium Sulfate