Release of bisphenol A and its derivatives from orthodontic adhesive systems available on the European market as a potential health risk factor

Konrad Małkiewicz 1  ,  
Department of Orthodontics, Medical University of Warsaw, Poland
Department of Drug Technology and Pharmaceutical Biotechnology, Medical University of Warsaw, Poland
Faculty of Management, Siedlce University of Natural Sciences and Humanities, Poland
Lubuski College of Public Health, Zielona Góra, Poland
Institute of Chemistry, Siedlce University of Natural Sciences and Humanities, Poland
Ann Agric Environ Med 2015;22(1):172–177
Treatment with fixed orthodontic appliances requires the application of adhesive systems to enable secure fastening of brackets and retainers to the surface of tooth enamel. The orthodontic bonding systems are similar in terms of chemical composition to dental filling materials, the chemical stability of which is not satisfactory. Particularly alarming is the release of bisphenol A and its derivatives to the external environment, which has been well-documented for materials used in conservative dentistry.

Material and Methods:
The aim of the study was an in vitro assessment of the release of biologically harmful bisphenol A and its derivatives from orthodontic adhesives available on the European market, as a potential health risk factor for orthodontic patients. [b]Material and methods[/b]. The study assessed levels of BPA, BPA polymers and Bis-GMA resin in eluates of six commonly used orthodontic adhesives: Light Bond, Transbond XT, Resilence, Aspire, GrĕnGloo and ConTec LC, obtained after one hour, 24 hours, 7 days and 31 days of material sample storage in water. The presence and concentration of the studied chemicals in the obtained solutions were identified using the HPLC method.

The highest (p≤0.05) concentration of BPA at 32.10µg/ml was observed in the Resilence material eluates. The highest concentration of poly-bisphenol A was found in solutions obtained after incubation of ConTec LC adhesive at 371.90µg/ml, whereas the highest amount of Bis-GMA resin (425.07µg/ml) was present in Aspire material eluates.

1) In conditions of the current experiment it was demonstrated that most of the assessed orthodontic adhesive resins available on the European market and released into the outside environment – biologically harmful bisphenol A or its derivatives, posing a potential threat to the patients’ health. 2) Release of BPA and its derivatives into aqueous solutions is the highest in the early stages of sample incubation.

Konrad Małkiewicz   
Department of Orthodontics, Medical University of Warsaw, Poland
1. Kloukos D, Pandis N, Eliades T. Bisphenol-A and residual monomer leaching from orthodontic adhesive resins and polycarbonate brackets: A systematic review. Am J Orthod Dentofacial Orthop. 2013; 143: 104–112.
2. Amirouche-Korichi A, Mouzali M, Watts D. Effects of monomer ratios and highly radiopaque fillers on degree of conversion and schrinkage-strain of dental resin composites. Dent Mater. 2009; 25: 1411–1418.
3. Moharamzadeh K, van Noort R, Brook IM, Scutt AM. HPLC analysis of components released from dental composites with different resin composition using different extraction media. J Mater Sci: Mater Med. 2007; 18: 133–137.
4. Leprince JG, Leveque P, Nystern B, Gallez B, Devaux J, Leloup G. New insight into the “depth of cure” of dimethacrylane-based dental composites. Dent Mater. 2012; 28: 512–520.
5. Finer Y, Santerre JP. Biodegradation of dental composite by esterases: dependence on enzyme concentration and specificity. J Biomater Sci Polym Ed. 2003; 14: 837–849.
6. Negishi T, Kawasaki K, Suzaki S, Maeda H, Ishii Y, Kyuwa S, Kuroda Y, Yoshikawa Y. Behavioral Alterations in Response to Fear-Provoking Stimuli and Tranylcypromine Induced by Perinatal Exposure to Bisphenol A and Nonylphenol in Male Rats. Environ Health Perspectiv. 2004; 112: 1159–1164.
7. Stump DG, Beck MJ, Radovsky A, Garman RH, Freshwater L, Sheets LP, Marty MS, Waechter JM, Dimond SS, van Miller JP, Shiotsuka RN, Beyer D, Chappelle AH, Hentges SG. Developmental neurotoxicity study of dietary bisphenol A in Sprague-Dawley rats. Toxicolog Sci. 2010; 115: 167–182.
8. Tyl RW, Myer CB, Marr MC, Thomas BF, Keimowitz AR, Brine DR, Veselica MM, Fail PA, Chang TY, Seely JC, Joiner RL, Butala JH, Dimond SS, Cagen SZ, Shiotuka RN, Stropp GD, Waechter JM. Three-Generation Reproductive Toxicity Study of Dietary Bisphenol A in CD Sprague-Dawley Rats. Toxicolog Sci. 2002; 68: 121–146.
9. European Commission directive 2011/8/EU http://eur-lex.europa.eu/LexUri-Serv/LexUriServ.do?uri=OJ:L:2011:026:0011:0014:EN:PDF (access: 2013.09.10).
10. Balakrishnan B, Henare K, Thorstensen EB, Ponnampalam AP, Mitchell MD. Transfer of bisphenol A across the human placenta. Am J Obstetrics Gyn. 2010; 202: 393–397.
11. Bakopoulou A, Papadopoulos T, Gerefis P. Molecular toxicology of substances released from resin based dental restorative materials. Int J Molec Sci. 2009; 10: 3861–3899.
12. Kleinsasser NH, Wallner BC, Harreus UA, Kleinjung T, Folwaczny M, Hickel R, Kehe K, Reichl FX: Genotoxicity and cytotoxicity of dental materials in human lymphocytes as assessed by a single cell microgel electrophoresis (comet) assay. J Dent. 2004; 32: 229–234.
13. Drozd K, Wysokinski D, Krupa R, Wozniak K. Bisphenol A-glycid methacrylate induces a broad spectrum of DNA damage In human lymphocytes. Arch Toxicol. 2011; 85: 1453–1461.
14. Eliades T, Eliades G, Brantley WA, Johnston WM. Residual monomer leaching from chemically-cured and visible light-cured orthodontic adhesives. Am J Orthod Dentofacial Orthop. 1995; 108: 316–321.
15. Eliades T, Hiskia A, Eliades G. Assessment of bisphenol-A release from orthodontic adhesives. Am J Orthod Dentofacial Orthop. 2007; 131(1): 72–75.
16. Eliades T, Voutsa D, Sifakakis I, Makou M, Katsaros Ch. Release of bisphenol A from light-cured adhesive bonded to lingual fixed retainers. Am J Orthod Dentofacial Orthop. 2011; 139: 192–195.
17. Kitahara Y, Takahashi S, Tsukagoshi M, Fujii T. Formation of bisphenol A by thermal degradation of poly(bisphenol A carbonate). Chemosphere. 2010; 80: 1281–1284.
18. Chang M-Ch, Chen L-I, Chan Ch-P, Lee J-J, Wang T-M, Yang T-T, Lin P-S, Lin H-J, Chang H-H, Jeng J-H. The role of reactive oxygenspecies and hemooxygenase-1 expression in the cytotoxicity, cell cycle alteration and apoptosis of dental pulp cells inducted by Bis-GMA. Biomater. 2010; 31: 8164–8171.
19. Blasiak J, Synowiec E, Tatnawska J, Czarny P, Popławski T, Reiter R.J. Dental methacrylates May Ebert genotoxic effects via the oxidative induction of DNA double strand breaks and the inhibition of their repair. Mol Biol Rep. 2012; 39: 7487–7496.
20. Zhang H-Q, Zhang X-F, Zhang L-J, Chao H-H, Pan B, Feng Y-M, Li L, Sun X-F, Shen W. Fetal exposure to bisphenol A affects the primordial follicle formation by inhibiting the meiotic progression of oocytes. Mol Biol Rep. 2012; 39: 5651–5657.
21. Bouskine A, Nebout M, Brücker-Davis F, Benahmed M, Fenichel P. Low Doses of Bisphenol A Promote Human Seminoma Cell Proliferation by Activating PKA and PKG via Membrane G-Protein-Coupled Estrogen Receptor. Environ Health Perspectiv. 2009; 117: 1053–1058.
22. Durando M, Kass L, Piva J, Sonnenschein C, Soto AM, Luque EH, Munoz de Toro M. Prenatal Bisphenol A Exposure Induces Preneoplastic Lesions in the Mammary Gland in Winstar Rats. Environ Health Perspectiv. 2007; 115: 80–86.
23. Poimenova A, Markaki E, Rachiotis C, Kitraki E. Corticosterone-regulated actions in the rat brain are affected by perinatal exposure to low dose of bisphenol A. Neurosci. 2010; 167: 741–749.
24. Salian S, Doshi T, Vanage G. Neonatal exposure of male rats to bisphenol A affects the fertility of male offspring. Life Sci. 2009; 85: 742–752.
25. Update on Bisphenol A for Use in Food Contact Applications U.S. Food and Drug Administration January 2010. FDA, 2010 http://www.fda.gov/newsevents/ publichealthfocus/ucm197739.html (access: 2013.09.10).