The effect of post-cure heating on residual, unreacted monomer in a commercial resin composite.
OBJECTIVE
This paper examined the influence of post-cure temperature on the amount of unreacted monomer remaining in a commercial light-cured resin composite restoration following initial light-curing and subsequent post-cure heating.


METHODS
Discs of composite were light-cured and then subjected to immediate post-cure heating (50, 75, 100, or 125 degrees C for 7 min) or were left unheated (control). They were then placed in a solvent for two weeks at 37 degrees C to extract the unreacted monomer. HPLC analysis was used to determine the amounts of TEGDMA, BIS-GMA, and ethoxylated BIS-GMA remaining after the different treatments. The amounts of each monomer leaching were compared using ANOVA with respect to the different curing treatments.


RESULTS
Even the lowest post-cure heat treatment (50 degrees C) resulted in 80% reduction in remaining, unreacted TEGDMA, 75% reduction in BIS-GMA, and 77% lower ethoxylated BIS-GMA than the light-cured only control. Post-cure heating at 75 degrees C and above resulted in the lowest amount of each type monomer remaining uncured in the polymer and did not significantly decrease with an increase in post-cure temperature for the most part.


CONCLUSIONS
One of the main benefits of post-cure heating of resin composite restorations could be the enhancement of biocompatibility of these restorations as a result of the significant decrease in potentially leachable, unreacted monomer.
Bagis
Y H
YH
University of Ankara School of Dentistry, Ankara, Turkey.
Rueggeberg
F A
FA
D000704:Analysis of Variance; D001672:Biocompatible Materials / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000032:analysis / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003188:Composite Resins / Q000032:analysis / Q000737:chemistry*; D004058:Diffusion; D006358:Hot Temperature; D006801:Humans; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000032:analysis / Q000737:chemistry; D011092:Polyethylene Glycols / Q000032:analysis / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000032:analysis / Q000737:chemistry; D019279:Resin Cements / Q000032:analysis / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013223:Statistics as Topic
D001672:Biocompatible Materials; D003188:Composite Resins; D008689:Methacrylates; D011109:Polymethacrylic Acids; D019279:Resin Cements; D012997:Solvents; C065770:Herculite XR; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C074277:ethoxylated bis-phenol A dimethacrylate; D017438:Bisphenol A-Glycidyl Methacrylate