Effect of bleaching on the elution of monomers from modern dental composite materials.
OBJECTIVE
The aim of this study was to evaluate the effect of bleaching on the elution of monomers from two modern composite materials.


METHODS
Two different resin composites (a nanohybrid the Filtek Supreme XT and an ormocer the Ceram X) were bleached with two products (hydrogen peroxide 38% for 45 min and carbamide peroxide 15% for 56 h). Four groups (n=10, diameter: 4.5 mm, thickness: 2 mm) of each material were fabricated, two for each bleaching product. One group was used as unbleached control and the other one was bleached. Then the samples were stored in 1 ml of 75 vol% ethanol at room temperature, and the storage medium was renewed after 24 h, 7 days, and 28 days. From the storage medium that was removed samples were prepared and analysed with LC-MS/MS.


RESULTS
None of the bleaching products had an effect on the amount of Bis-GMA and TEGDMA released from Ceram X. The amount of Bisphenol A released from the bleached samples of Ceram X was significantly lower compared to the control samples. Bleaching reduced significantly the amount of Bis-GMA released from Filtek Supreme XT. The amount of TEGDMA released from Filtek Supreme XT was not affected by bleaching.


CONCLUSIONS
The bleaching agents tested in the present study reduced the amount of some of the monomers released from the two composite materials. Bleaching of modern composite materials does not increase the release of monomers.
Polydorou
Olga
O
Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Dental School and Hospital, Hugstetter Strasse 55, 79106 Freiburg i. Br., Germany. olga.polydorou@uniklinik-freiburg.de
Beiter
Johannes
J
König
Armin
A
Hellwig
Elmar
E
Kümmerer
Klaus
K
D001559:Benzhydryl Compounds; D017438:Bisphenol A-Glycidyl Methacrylate / Q000032:analysis / Q000737:chemistry; D000077463:Carbamide Peroxide; D002516:Ceramics / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003188:Composite Resins / Q000737:chemistry*; D004338:Drug Combinations; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D013058:Mass Spectrometry; D008422:Materials Testing; D008689:Methacrylates / Q000032:analysis / Q000737:chemistry; D063225:Organically Modified Ceramics; D016877:Oxidants / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry*; D010636:Phenols / Q000032:analysis / Q000737:chemistry; D011092:Polyethylene Glycols / Q000032:analysis / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000032:analysis / Q000737:chemistry; D011140:Polyurethanes / Q000032:analysis / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014073:Tooth Bleaching; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D017438:Bisphenol A-Glycidyl Methacrylate; D000077463:Carbamide Peroxide; D003188:Composite Resins; D004338:Drug Combinations; D000431:Ethanol; D006861:Hydrogen Peroxide; D008689:Methacrylates; D063225:Organically Modified Ceramics; D016877:Oxidants; D010545:Peroxides; D010636:Phenols; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D012821:Silanes; D012997:Solvents; D014508:Urea; C520091:CeramX; C474035:Filtek Supreme; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; C005044:hydroxyethyl methacrylate; C006780:bisphenol A; D000098826:Bisphenol A Compounds