Excretion of dental resin monomers and metabolic intermediates via urine in guinea pigs

Abstract 

Objective

Monomers like BisGMA (Bisphenol-A-glycidyldimethacrylate) and comonomers like TEGDMA (triethyleneglycoldimethacrylate) are used in dental restorative materials in order to build up the three-dimensional network of filling materials. Since earlier investigations revealed uptake and subsequent metabolism of unpolymerized remainders of (co)monomers, the present experiment investigates the metabolic urine pattern of guinea pigs (n=4) after application of TEGDMA or BisGMA (each dose=0.02mmol/kg body weight=100%), respectively.

Methods

For the investigations BisGMA was pre-dissolved in DMSO and subsequently diluted with 0.9% NaCl solution (final DMSO concentration 1%) and TEGDMA was dissolved in 0.9% NaCl solution. The solutions were administered with a gastric tube into the animals. Control animals received either 0.9% NaCl or 0.9% NaCl solution with 1% DMSO solution.

Results

After 24h in collected urine the following metabolites were identified. After administration of TEGDMA (mean relative concentration of administered substances)±s.d. [%]; n=4): unchanged TEGDMA: 12±1.5%, MA: 2.4±0.8%, and triethyleneglycol: 35±2.2%. After administration of BisGMA (mean±s.d. [%]; n=4): unchanged BisGMA: 11.4±2.7%, MA: 2.2±0.6%, and bisphenol-A-bis(2,3-dihydroxypropyl)ether: 60.1±5.2%).

Conclusion

No further metabolites like the previously identified intermediate 2,3-epoxymethacrylic acid and derived reaction products were identified in the urine, indicating that these metabolites must have reacted further.

Keywords: TEGDMA, BisGMA, Metabolites, Urine