Leachability of plasticizer and residual monomer from commercial temporary restorative resins.
OBJECTIVE
This study was performed to determine the compositions of commercial temporary restorative resins and to evaluate the leachability of plasticizer and residual monomer from them.


METHODS
The chemicals in four commercial temporary restorative resins (Dura Seal, Fit Seal, Plast Seal Quick, and Poly Seal) were detected by GCMS and HPLC. The amounts of plasticizers and residual monomers that leached from cured resin samples immersed in ethanol for 1 h to 14 d were determined by HPLC.


RESULTS
Phthalate esters used as plasticizers contained 40-55 wt% either di-n-butyl phthalate (DBP) or butyl phthalyl butyl glycolate. The resin monomer included methyl methacrylate (MMA) or a mixture of MMA and 2-hydroxyethyl methacrylate (HEMA); 1,3-butanediol dimethacrylate was added as a cross-linking agent. Each resin contained 40-60 wt% monomer. The amounts of phthalate esters leached increased with immersion time up to 7 d, reaching 120-190 microg/mg, and did not change subsequently. The residual monomers leached gradually for up to 3d and did not change subsequently. The amount of leached residual monomer (MMA, HEMA) was 20-90 microg/mg after 3d storage. More than 50% of the leachable plasticizers and monomers were eluted from the cured resins within 24 and 3 h, respectively.


CONCLUSIONS
The amounts of leached plasticizers and residual monomers were extremely large compared with the concentrations of endocrine disrupters and their potentially genotoxic effects. Therefore, it is very important to evaluate the leachability of these compounds from temporary restorative resins.
Kawahara
T
T
Department of Operative Dentistry, Graduate School of Biomedical Science, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
Nomura
Y
Y
Tanaka
N
N
Teshima
W
W
Okazaki
M
M
Shintani
H
H
D000180:Acrylic Resins / Q000737:chemistry*; D002072:Butylene Glycols / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003794:Dental Restoration, Temporary; D003993:Dibutyl Phthalate / Q000031:analogs & derivatives* / Q000737:chemistry; D004058:Diffusion; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D020366:Methylmethacrylate / Q000737:chemistry*; D010968:Plasticizers / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D013997:Time Factors
D000180:Acrylic Resins; D002072:Butylene Glycols; D008689:Methacrylates; C102650:Plast Seal; D010968:Plasticizers; D012117:Resins, Synthetic; D020366:Methylmethacrylate; D003993:Dibutyl Phthalate; C028491:1,3-butylene glycol; C005044:hydroxyethyl methacrylate; C030189:Dura-Seal; C048569:butyl phthalyl butyl glycolate; D019904:Polymethyl Methacrylate