Dental Amalgam Waste in Dentistry: Sources, Environmental Impact and Management Strategies
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Among the restorative materials, dental amalgam is one of the most commonly used due to its superior characteristics, including clinical durability, affordability, and clinically reliable properties. However, its mercury content has raised environmental concerns, especially regarding the waste generated during routine procedures such as placing, removing, finishing, and replacing old amalgam restorations. This waste can enter dental wastewater systems through plumbing and suction, which is why dental clinics are such an important source of mercury for municipal wastewater treatment plants, even though dentistry only contributes a small amount of global anthropogenic mercury emissions. Once released, amalgam particles can build up in sewage sludge or enter water bodies. Mercury can turn into methylmercury and accumulate in living things, which is considered the most hazardous for the environment and public health. As a result, various regulatory bodies have set guidelines to limit the amount of mercury that can be released from dental offices. Best management practices, including separating waste, recycling, and using ISO-certified amalgam separators, have been shown to significantly lower the amount of mercury released. This review provides insights into the recent information regarding the sources of amalgam waste, its effect on the environment, the regulatory framework, and ways to manage it. It also emphasizes how important it is for dental professionals to use environmentally friendly methods to reduce the environmental impact of dental amalgam.
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This work is licensed under a Creative Commons Attribution 4.0 International License.
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1. Anusavice KJ. Dental Amalgams (In) Philips’ Science of Dental Materials. 11th Ed., Saunders Elsevier, St Louis, Missouri, USA. 2007: p. 495-544.
2. Alla RK. Dental Materials Science (In) Dental Amalgam. Jaypee Brothers Medical Publishers Pvt. Ltd., New Delhi, India. 2013: p. 78-91.
3. Mackenzie L. Dental amalgam: a practical guide. Dental Update. 2021;48(8):607-18. https://doi.org/10.12968/denu.2021.48.8.607
4. Bharti R, Wadhwani KK, Tikku AP, Chandra A. Dental amalgam: An update. J Conserv Dent Endod. 2010;13(4):204-8. https://doi.org/10.4103/0972-0707.73380
5. Chin G, Chong J, Kluczewska A, Lau A, Gorjy S, Tennant M. The environmental effects of dental amalgam. Aust Dent J. 2000;45(4):246-9. https://doi.org/10.1111/j.1834-7819.2000.tb00258.x
6. Haque N, Yousaf S, Nejatian T, Youseffi M, Mozafari M, Sefat F. Dental amalgam. (In) Advanced Dental Biomaterials Woodhead Publishing, 2019: p. 105-125. https://doi.org/10.1016/B978-0-08-102476-8.00006-2
7. Amalgam Separators and Waste Best Management — ADA overview on environmental impacts of dental mercury and separator usage. https://www.ada.org/resources/ada-library/oral-health-topics/amalgam-separators Accessed on 14.11.2025
8. Brownawell AM, Berent S, Brent RL, Bruckner JV, Doull J, Gershwin EM, Hood RD, Matanoski GM, Rubin R, Weiss B, Karol MH. The potential adverse health effects of dental amalgam. Toxicol Rev. 2005;24(1):1-10. https://doi.org/10.2165/00139709-200524010-00001
9. Muhamedagic B, Muhamedagic L, Masic I. Dental office waste–public health and ecological risk. Mater Socio-medica. 2009;21(1):35-8. https://doi.org/10.5455/aim.2009.21.35-39
10. Shraim A, Alsuhaimi A, Al-Thakafy JT. Dental clinics: a point pollution source, not only of mercury but also of other amalgam constituents. Chemosphere. 2011;84(8):1133-9. https://doi.org/10.1016/j.chemosphere.2011.04.034
11. Sanderson S. The great dental amalgam debate. Brit Dent J. 2022;233(10):874. https://doi.org/10.1038/s41415-022-5217-3
12. Jebur N, Vinall-Collier K, Umair AA, Aggarwal VR. Dental amalgam teaching phase-out-a step too soon? Foundation trainees' experience of amalgam use in dental school compared to practice: a mixed-methods survey. Brit Dent J. 2023;235(5):329-34. https://doi.org/10.1038/s41415-023-6228-4
13. Phasing-down the Use of Dental Amalgam | Global Mercury Partnership — UNEP info on Minamata Convention requirements and global phase-down of amalgam. https://www.unep.org/globalmercurypartnership/our-work/mercury-products/phasing-down-the-use-of-dental-amalgam Accessed on 14.11.2025
14. Geier DA, Geier MR. Dental amalgam fillings and mercury vapor safety limits in American adults. Hum Exp Toxicol. 2022;41:09603271221106341. https://doi.org/10.1177/09603271221106341
15. Chadwick RG, Lloyd CH. Dental amalgam: the history and legacy you perhaps never knew?. Brit Dent J. 2022;232(9):633-7. https://doi.org/10.1038/s41415-022-4204-z
16. Kisumbi BK, Osiro OA, Gathece LW, Maina SW. Dental Amalgam Phase‐Down—Status, Alternatives, Strategies and Preparedness for Implementation: A Review. Int J Dent. 2025;2025(1):6688410. https://doi.org/10.1155/ijod/6688410
17. American Dental Association. Amalgam Separators and Waste Best Management. ADA Oral Health Topics. https://www.ada.org/resources/ada-library/oral-health-topics/amalgam-separators Accessed 14.11.2025
18. Mahesh S, Benamanahalli Motaiah K, Shivaswamy M, Nandigunda Subramani M, Kumar Jain Shanthilal V. Dental wastewater treatment using electro-chemical coagulation unit process. Sep Sci Technol. 2025;60(9-10):1171-88. https://doi.org/10.1080/01496395.2025.2483761
19. Sahana M, Krishna BM, Mahesh S. Raw Dental Wastewater Treatment by Electro-Chemical Coagulation Using Copper and Stainless Steel Electrodes: A Comparative Study. Int J Environ Res. 2025;19(6):275. https://doi.org/10.1007/s41742-025-00941-1
20. Sudi SM, Naidoo S. Perspectives on the Minamata Convention and dental amalgam waste management in South Africa. South African Dent J. 2024;79(10):542-6. https://doi.org/10.17159/sadj.v79i10.19172
21. Foláyan MO, Virtanen JI, Gaffar B, Abodunrin O, Sun IG, Duangthip D, Kemoli A, Masumo RM, Vukovic A, Al-Batayneh OB, Mfolo T. Scoping review on the association between early childhood caries and responsible resource consumption and production: exploring Sustainable Development Goal 12. BMC Oral Health. 2024;24(1):98. https://doi.org/10.1186/s12903-023-03831-0
22. Dormen M, Özkan P. Sustainable Dental Approaches for the Environment and Human Health: A Traditional Literature Review. HRU Int J Dent Oral Res. 2025;5(1):51-8. https://doi.org/10.61139/ijdor.1649869
23. Shrikrishna Bhat V, Shrikrishna Bhat T, Balasaheb Chougule M. Biomedical waste analysis in the rural area of Warananagar-Kodoli, Maharashtra, India. Environ Health Eng Manag J. 2024;11(4):429-40. https://doi.org/10.34172/EHEM.2024.42
24. Eshrati M, Momeniha F, Momeni N, Ahmadi E, Hashemian A, Kashani H, Alaeddini M. Clinical Guide Adaptation for Amalgam Waste Management in Dental Settings in Iran. Front Dent. 2024;21:44. https://doi.org/10.18502/fid.v21i44.17053
25. Frost AL. New dental amalgam handling regulations-what every dentist needs to know. Int Dentistry (Afr Ed). 2025;15(2):32-28.
26. Letzel H, de Boer EA, Van T Hof MA. An estimation of the size distribution of amalgam particles in dental treatment waste. J Dent Res. 1997;76(3):780-8. https://doi.org/10.1177/00220345970760031101
27. Adegbembo AO, Watson PA, Lugowski SJ. The weight of wastes generated by removal of dental amalgam restorations and the concentration of mercury in dental wastewater. J Can Dent Assoc. 2002;68(9):553-8.
28. American Dental Association. Best management practices for amalgam waste. J Okla Dent Assoc. 2004;95(1):28-30.
29. Skare I, Engqvist A. Human exposure to mercury and silver released from dental amalgam restorations. Arch Environ Health: An Int J. 1994;49(5):384-94. https://doi.org/10.1080/00039896.1994.9954991
30. Drummond JL, Cailas MD, Croke K. Mercury generation potential from dental waste amalgam. J Dent. 2003;31(7):493-501. https://doi.org/10.1016/S0300-5712(03)00083-6
31. Hylander LD, Meili M. 500 years of mercury production: global annual inventory by region until 2000 and associated emissions. Sci Total Environ. 2003;304(1-3):13-27. https://doi.org/10.1016/S0048-9697(02)00553-3
32. Warwick D, Just A. Dental Amalgam and the Environment. ChampionsGate, FL: International Academy of Oral Medicine and Toxicology (IAOMT). 2014 May.
33. EPA. Locating and estimating air emissions from sources of mercury and mercury compounds. 1997. EPA-454/R-97-012. https://www.epa.gov/sites/default/files/2020-11/documents/mercury.pdf Accessed on 23.11.2025.
34. Pacyna EG, Pacyna JM, Steenhuisen F, Wilson S. Global anthropogenic mercury emission inventory for 2000. Atmos Environ. 2006;40(22):4048-63. https://doi.org/10.1016/j.atmosenv.2006.03.041
35. Ullrich SM, Tanton TW, Abdrashitova SA. Mercury in the aquatic environment: a review of factors affecting methylation. Crit Rev Env Sci Tec. 2001;31(3):241-93. https://doi.org/10.1080/20016491089226
36. Lindberg S, Bullock R, Ebinghaus R, Engstrom D, Feng X, Fitzgerald W, Pirrone N, Prestbo E, Seigneur C. A synthesis of progress and uncertainties in attributing the sources of mercury in deposition. Ambio. 2007;36(1):19-33. https://doi.org/10.1579/0044-7447(2007)36[19:ASOPAU]2.0.CO;2
37. Richardson GM, Wilson R, Allard D, Purtill C, Douma S, Graviere J. Mercury exposure and risks from dental amalgam in the US population, post-2000. Sci Total Environ. 2011;409(20):4257-68. https://doi.org/10.1016/j.scitotenv.2011.06.035
38. Clarkson TW, Magos L. The toxicology of mercury and its chemical compounds. Crit Rev Toxicol. 2006;36(8):609-62. https://doi.org/10.1080/10408440600845619
39. Wolfe MF, Schwarzbach S, Sulaiman RA. Effects of mercury on wildlife: a comprehensive review. Environ Toxicol Chem. 1998;17(2):146-60. https://doi.org/10.1002/etc.5620170203
40. Petersen PE, Baez R, Kwan S, Ogawa H. World Health Organization Future use of materials for dental restoration. In Proceedings of the Report of the Meeting Convened at WHO HQ. pp. 1-67.
41. United Nations Environment Programme. Minamata Convention on Mercury. UNEP; 2013. https://www.unep.org/resources/report/minamata-convention-mercury Accessed 21.11.2025.
42. Mackey TK, Contreras JT, Liang BA. The Minamata Convention on Mercury: Attempting to address the global controversy of dental amalgam use and mercury waste disposal. Sci Total Environ. 2014;472:125-9. https://doi.org/10.1016/j.scitotenv.2013.10.115
43. Council of European Communities. Council Directive 84/156/EEC on mercury discharges. Official Journal of the European Communities. 1984. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:31984L0156 Accessed on 22.11.2025.
44. Hylander LD, Lindvall A, Uhrberg R, Gahnberg L, Lindh U. Mercury recovery in situ of four different dental amalgam separators. Sci Total Environ. 2006;366(1):320-36. https://doi.org/10.1016/j.scitotenv.2005.07.007
45. U.S. Environmental Protection Agency. Dental effluent guidelines and mercury reduction. https://www.epa.gov/eg/dental-effluent-guidelines Accessed on 22.11.2025
46. Ritchie KA, Burke FJ, Gilmour WH, Macdonald EB, Dale IM, Hamilton RM, et al. Mercury vapour levels in dental practices and body mercury levels of dentists and controls. Brit Dent J. 2004;197(10):625-32. https://doi.org/10.1038/sj.bdj.4811831
47. Jones DW. Exposure or absorption and the crucial question of limits for mercury. J Can Dent Assoc. 1999;65(1):42-6.9.
48. Arenholt-Bindslev D. Environmental Aspects. In Biocompatibility of Dental Materials 2008. Berlin, Heidelberg: Springer Berlin Heidelberg. 325-334. https://doi.org/10.1007/978-3-540-77782-3_13
49. Osiro OA, Kariuki DK, Gathece LW. The Minamata Convention on Mercury and its implications for management of dental caries in low-and middle-income countries. Int Dent J. 2019;69(4):247-51. https://doi.org/10.1111/idj.12461
50. Musliu A, Beqa L, Kastrati G. The use of dental amalgam and amalgam waste management in Kosova: An environmental policy approach. Integrated Environmental Assessment and Management. 2021;17(5):1037-44. https://doi.org/10.1002/ieam.4408
51. Toxicological Profile for Mercury. Atlanta (GA): Agency for Toxic Substances and Disease Registry (US); 2024 Oct. Table 7-1, Regulations and Guidelines Applicable to Mercury (Hg). https://www.ncbi.nlm.nih.gov/books/NBK611018/table/ch7.tab1/ Accessed 21.11.2025.
52. Sara Johansson. Tackling Mercury Pollution of EU Waters: Why coal combustion must end by 2027 at the latest. 2021, The European Environmental Bureau (EEB). https://eeb.org/wp-content/uploads/2021/12/EEB_Mercury_Briefing-1.pdf Accessed on 21.11.2025
53. OSHA Instruction. Inorganic Mercury and Its Compounds. CPL 02-02-006. 1978. https://www.osha.gov/enforcement/directives/cpl-02-02-006 Accessed 20.11.2025
54. Cieplik F, Dame-Teixeira N, Priya H, Schmalz G, Scholz K, Tenuta l, et al. Policy Statement on Safety of Dental Amalgam. 2025. https://www.iadr.org/science-policy/safety-dental-amalgam Accessed 20.11.2025.
55. Tibau AV, Grube BD. Mercury contamination from dental amalgam. J Health Pollut. 2019;9(22):190612. https://doi.org/10.5696/2156-9614-9.22.190612
56. Warwick D, Young M, Palmer J, Ermel RW. Mercury vapor volatilization from particulate generated from dental amalgam removal with a high-speed dental drill–a significant source of exposure. J Occup Med Toxicol. 2019;14(1):22. ttps://doi.org/10.1186/s12995-019-0240-2
57. Skare I, Engqvist A. Human exposure to mercury and silver released from dental amalgam restorations. Arc Environ Health: An Int J. 1994;49(5):384-94. https://doi.org/10.1080/00039896.1994.9954991
58. Jokstad A, Fan PL. Amalgam waste management. Int Dent J. 2006;56(3):147-53. https://doi.org/10.1111/j.1875-595X.2006.tb00087.x
59. Smith L, Ali M, Agrissais M, Mulligan S, Koh L, Martin N. A comparative life cycle assessment of dental restorative materials. Dent Mater. 2023;39(1):13-24. https://doi.org/10.1016/j.dental.2022.11.007
60. Bjørklund G, Dadar M, Mutter J, Aaseth J. The toxicology of mercury: Current research and emerging trends. Environ Res. 2017;159:545-554. https://doi.org/10.1016/j.envres.2017.08.051
61. Mackert Jr JR, Berglund A. Mercury exposure from dental amalgam fillings: absorbed dose and the potential for adverse health effects. Crit Rev Oral Biol Med. 1997;8(4):410-36. https://doi.org/10.1177/10454411970080040401
62. Vandeven JA, McGinnis SL. An assessment of mercury in the form of amalgam in dental wastewater in the United States. Water, Air and Soil Pollution. Water Air Soil Pollut. 2005;164(1):349-366. https://doi.org/10.1007/s11270-005-4008-1
63. Fan PL, Batchu H, Chou HN, Gasparac W, Sandrik J, Meyer DM. Laboratory evaluation of amalgam separators. J Am Dent Assoc. 2002;133(5):577-89. https://doi.org/10.14219/jada.archive.2002.0233
64. International Standard ISO 11143. Dental Equipment–Amalgam Separators; 1999. Geneva, Switzerland: International Organisation for Standardisation; 1999. 1–23.
65. Drummond JL, Hathorn RM, Cailas MD. Particle size analysis of dental waste stream components. Dent Mater. 2001;17:322–332. https://doi.org/10.1016/S0109-5641(00)00090-7
66. Drummond JL, Liu Y, Wu TY, Cailas MD. Particle versus mercury removal efficiency of amalgam separators. J Dent. 2003;31(1):51-8. https://doi.org/10.1016/S0300-5712(02)00067-2
67. Jones DW. Putting dental mercury pollution into perspective. Brit Dent J. 2004;197(4):175-7. https://doi.org/10.1038/sj.bdj.4811564
68. Kall J, Robertson K, Sukel AP, Just MA. International Academy of Oral Medicine and Toxicology (IAOMT) Position Paper against Dental Mercury Amalgam Fillings for Medical and Dental Practitioners, Dental Students, Dental Patients, and Policy. 1-91. https://elearning.iaomt.org/wp-content/uploads/2022/05/IAOMT-Position-Paper-on-Dental-Amalgam.pdf Accessed on 20.11.2025.
69. Hiltz M. The environmental impact of dentistry. J Can Dent Assoc. 2007;73(1):59-62.
70. Saridena USNG, Sanka GSSJ, Alla RK, Ramaraju AV, Sajjan MC S, Mantena SR. An overview of advances in glass ionomer cements. Int J Dent Mater. 2022;4(4):89-94. https://doi.org/10.37983/IJDM.2022.4403
71. Gosavi SS, Gosavi SY, Alla RK. Local and systemic effects of unpolymerised monomers. Dent Res J. 2010;7(2):82-7.
72. Alla RK, Sanka GSSJL, Saridena USNG, Ramaraju AV, Raju M, Mantena SR. Fiber-Reinforced Composites in Dentistry: Enhancing structural integrity and aesthetic appeal. Int J Dent Mater. 2023;5(3):78-85. https://doi.org/10.37983/IJDM.2023.5303
73. Dara L, Buchi D, Mantena SR, K MV, D BR, Chandrappa V. Recent Advances in Dental Composites: An Overview. Int J Dent Mater. 2019;1(2):48-54. https://doi.org/10.37983/IJDM.2019.1202
74. Mudunuri S, Madhu Varma K, Kalyan Satish R, Sita Rama Kumar M, Sai Dinesh J, Anil Kumar P. Fiber-reinforced composites in endodontic practice: a review. Int J Dent Mater. 2020;2(4):122-34. https://doi.org/10.37983/IJDM.2020.2404
75. Fleisch AF, Sheffield PE, Chinn C, Edelstein BL, Landrigan PJ. Bisphenol A and related compounds in dental materials. Pediatrics. 2010;126(4):760-8. https://doi.org/10.1542/peds.2009-2693
76. Bengtsson UG, Hylander LD. Increased mercury emissions from modern dental amalgams. Biometals. 2017;30(2):277-83. https://doi.org/10.1007/s10534-017-0004-3
77. Sakchhi S, Elbanna L, Chakor M, Nikferjam AZ, Saeedi N, Badve S, et al. Green Dentistry: Sustainable Practices and Materials for a Healthier Planet. Int J Dent Mater. 2025;7(3):84-92. https://doi.org/10.37983/IJDM.2025.7303
78. Duane B, Stancliffe R, Miller FA, Sherman J, Pasdeki-Clewer E. Sustainability in dentistry: a multifaceted approach needed. J Dent Res. 2020;99(9):998-1003. https://doi.org/10.1177/0022034520919391