title: Effect of solution temperature on the mechanical properties of dual-cure resin cements.
abstract: OBJECTIVE
  This study was to evaluate the effect of the solution temperature on the mechanical properties of dualcure resin cements.
  
  
  METHODS
  For the study, five dual-cure resin cements were chosen and light cured. To evaluate the effect of temperature on the specimens, the light-cured specimens were immersed in deionized water at three different temperatures (4, 37 and 60℃) for 7 days. The control specimens were aged in a 37℃ dry and dark chamber for 24 hours. The mechanical properties of the light-cured specimens were evaluated using the Vickers hardness test, three-point bending test, and compression test, respectively. Both flexural and compressive properties were evaluated using a universal testing machine. The data were analyzed using a two way ANOVA with Tukey test to perform multiple comparisons (α=0.05).
  
  
  RESULTS
  After immersion, the specimens showed significantly different microhardness, flexural, and compressive properties compared to the control case regardless of solution temperatures. Depending on the resin brand, the microhardness difference between the top and bottom surfaces ranged approximately 3.3-12.2%. Among the specimens, BisCem and Calibra showed the highest and lowest decrease of flexural strength, respectively. Also, Calibra and Multilink Automix showed the highest and lowest decrease of compressive strength, respectively compared to the control case.
  
  
  CONCLUSIONS
  The examined dual-cure resin cements had compatible flexural and compressive properties with most methacrylate-based composite resins and the underlying dentin regardless of solution temperature. However, the effect of the solution temperature on the mechanical properties was not consistent and depended more on the resin brand.
authors.affiliation: Department of Prosthodontics, School of Dentistry, Dental Research Institute, Pusan National University, Yangsan, Republic of Korea.
authors.forename: En-Sook
authors.initials: ES
authors.lastname: Kang
authors.forename: Yeong-Chan
authors.initials: YC
authors.lastname: Jeon
authors.forename: Chang-Mo
authors.initials: CM
authors.lastname: Jeong
authors.forename: Jung-Bo
authors.initials: JB
authors.lastname: Huh
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Yun
authors.forename: Yong-Hoon
authors.initials: YH
authors.lastname: Kwon
keywords: Compressive properties; Dual-cure resin cements; Flexural properties; Microhardness; Solutiontemperature