title: Comparison of polymer-based temporary crown and fixed partial denture materials by diametral tensile strength.
abstract: OBJECTIVE
  The purpose of this study was to investigate the diametral tensile strength of polymer-based temporary crown and fixed partial denture (FPD) materials, and the change of the diametral tensile strength with time.
  
  
  METHODS
  One monomethacrylate-based temporary crown and FPD material (Trim) and three dimethacrylate-based ones (Protemp 3 Garant, Temphase, Luxtemp) were investigated. 20 specimens (ø 4 mm × 6 mm) were fabricated and randomly divided into two groups (Group I: Immediately, Group II: 1 hour) according to the measurement time after completion of mixing. Universal Testing Machine was used to load the specimens at a cross-head speed of 0.5 mm/min. The data were analyzed using one-way ANOVA, the multiple comparison Scheffe test and independent sample t test (α = 0.05).
  
  
  RESULTS
  Trim showed severe permanent deformation without an obvious fracture during loading at both times. There were statistically significant differences among the dimethacrylate-based materials. The dimethacrylate-based materials presented an increase in strength from 5 minutes to 1 hour and were as follows: Protemp 3 Garant (23.16 - 37.6 MPa), Temphase (22.27 - 28.08 MPa), Luxatemp (14.46 - 20.59 MPa). Protemp 3 Garant showed the highest value.
  
  
  CONCLUSIONS
  The dimethacrylate-based temporary materials tested were stronger in diametral tensile strength than the monomethacrylate-based one. The diametral tensile strength of the materials investigated increased with time.
authors.affiliation: Department of Dentistry, School of Medicine, Ajou University, Suwon, Korea.
authors.forename: Seung-Ryong
authors.initials: SR
authors.lastname: Ha
authors.forename: Jae-Ho
authors.initials: JH
authors.lastname: Yang
authors.forename: Jai-Bong
authors.initials: JB
authors.lastname: Lee
authors.forename: Jung-Suk
authors.initials: JS
authors.lastname: Han
authors.forename: Sung-Hun
authors.initials: SH
authors.lastname: Kim