Uptake, clearance and metabolism of TEGDMA in guinea pigs.
OBJECTIVE
The resin monomer triethyleneglycoldimethacrylate (TEGDMA) is used as a diluent in many resin-based bonding, cementing and direct tooth filling materials.


METHODS
In the present study the uptake and the clearance of 14C-TEGDMA applied via different routes were examined in vivo in guinea pigs. TEGDMA (0.02 mmol/kg by weight labeled with a tracer dose 14C-TEGDMA 0.7Bq/g by weight) was administered by gastric tube or by subcutaneous injection. Urine, feces, and exhaled carbon dioxide were collected for 24h after administration. The animals were killed 24h after the beginning of the experiment and various organs removed and 14C-radioactivity measured.


RESULTS
It was apparent that 14C-TEGDMA was taken up rapidly from the stomach and small intestine after gastric administration and was widely distributed in the body following administration by each of the routes. Clearance from most tissues following gastric and intradermal administration was essentially complete within one day. Low fecal 14C-levels (<1% of the administered dose) and urinary levels of about 15% after 24h were noted with each route of administration. Direct measurement of exhaled carbon dioxide showed that 60-65% of the administered dose of 14C left the body via the lungs during 24h. It is likely that 14C-pyruvate is formed in vivo resulting possibly in the formation of toxic 14C-TEGDMA-intermediates.


CONCLUSIONS
Despite using a high administered dose, the peak TEGDMA levels in all tissues examined after 24h were at least 100,000-fold less than known toxic levels.
Reichl
Franz-Xaver
FX
Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr. 26, 80336, Munich, Germany. reichl@lrz.uni-meunchen.de
Durner
Jürgen
J
Hickel
Reinhard
R
Spahl
Wolfgang
W
Kehe
Kai
K
Walther
Udo
U
Gempel
Klaus
K
Liebl
Bernhard
B
Kunzelmann
Karl-Heinz
KH
Hume
Wyatt
W
D000704:Analysis of Variance; D000818:Animals; D001944:Breath Tests; D003188:Composite Resins / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity; D005243:Feces; D006168:Guinea Pigs; D007408:Intestinal Absorption; D008297:Male; D008657:Metabolic Clearance Rate; D011092:Polyethylene Glycols / Q000032:analysis / Q000493:pharmacokinetics* / Q000633:toxicity; D011109:Polymethacrylic Acids / Q000032:analysis / Q000493:pharmacokinetics* / Q000633:toxicity; D019289:Pyruvic Acid / Q000032:analysis; D014018:Tissue Distribution; D014556:Urine
D003188:Composite Resins; D011109:Polymethacrylic Acids; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D019289:Pyruvic Acid