Influence of paste temperature at curing on conversion rate and bending strength of light-cured dental composites.
Pastes of three dental composites were tempered to 20 degrees C, 37 degrees C and 60 degrees C. Test specimens (22 x 2 x 2 mm) were cured by light and stored in deionized water. Three-point bending strength was measured after 1 h and after 24 h. Degree of conversion on the surface exposed to the curing light and the opposite surfaces at the bottom of the mould was analysed by Fourier transform infrared (FTIR) after 1 h. After 1 h, specimens produced using the pastes cured at 60 degrees C showed significantly higher bending strength than the specimens produced using pastes cured at 20 degrees C and 37 degrees C. However, after 24 h the composites pretempered at the lower temperatures had developed the same level of bending strength as the composites cured at 60 degrees C. An increase in the degree of conversion with increased paste temperature was found in all materials after 1 h.
Li
J
J
Centre for Dental Technology and Biomaterials, Karolinska Institute, Huddinge, Sweden.
Nicander
I
I
von Beetzen
M
M
Sundström
F
F
D000180:Acrylic Resins / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D006358:Hot Temperature; D008422:Materials Testing; D018583:Pliability; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements; D017550:Spectroscopy, Fourier Transform Infrared
D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011140:Polyurethanes; D019279:Resin Cements; C065770:Herculite XR; C065771:P50 composite resin; D017438:Bisphenol A-Glycidyl Methacrylate