title: Dimensional change of a calcium aluminate cement for posterior restorations in aqueous and dry media.
abstract: OBJECTIVE
  A calcium aluminate cement has recently been developed, with claims of being an alternative to dental amalgam and resin composites in posterior cavities. However, its' mechanical properties are not well evaluated and the aim of the study was therefore, to evaluate its' dimensional stability over time.
  
  
  METHODS
  The dimensional changes of the cement, Doxadent, and two composite resins, Esthet-X and InTen-S, were tested during 360 d. The specimens were stored at 37+/-1 degrees C either in 100% air humidity (dry) or immersed in distilled water (wet), except for the first 24h when all specimens were stored at 100% air humidity and 37+/-1 degrees C.
  
  
  RESULTS
  During the first 24h, Doxadent decreased in volume with 0.04%, while InTen-S and Esthet-X decreased with 1.60 and 1.75%, respectively. From d 1-360, the dry Doxadent specimens increased in volume with 2.0% and in weight with 5.5%, while the corresponding increase for the wet specimens were 4.1 and 6.3%, respectively. The volume of both composites increased 0.8% or less in dry and wet conditions, while the increase in weight for InTen-S was 1.2% for the wet specimens and 0.6% for the dry. The corresponding figures for Esthet-X were 0.7 and 0.2%.
  
  
  CONCLUSIONS
  Doxadent was less dimensionally stable than the composites tested. Doxadent increased 2 times more in volume immersed in water than in 100% air humidity, while the increase in weight was almost similar. The clinical implications of the results found in the present study are uncertain. A material that continues to absorb water during prolonged periods and continues to react is questionable for clinical use.
authors.affiliation: Department of Odontology, Dental Technician Program, Umeå University, Umeå, Sweden. anders.berglund@odont.umu.se
authors.forename: A
authors.initials: A
authors.lastname: Berglund
authors.forename: Anna Karin
authors.initials: AK
authors.lastname: Hulterström
authors.forename: Ewa
authors.initials: E
authors.lastname: Gruffman
authors.forename: Jan W V
authors.initials: JW
authors.lastname: van Dijken
mesh_terms: D000042:Absorption; D017607:Aluminum Compounds; D017610:Calcium Compounds; D003188:Composite Resins; D003738:Dental Cements; D003793:Dental Restoration, Permanent; D004355:Drug Stability; D004356:Drug Storage; D006813:Humidity; D008963:Molar; D013997:Time Factors; D014867:Water
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003188:Composite Resins; D003738:Dental Cements; C462459:DoxaDent; C466112:Esthet-X; C477684:In Ten-S composite resin; D014867:Water; C035219:calcium aluminate