The truth is that many composites are superior to amalgam. A 1994 study by the prestigious Clinical Research Associates group of Provo, Utah, examined 21 dental filling materials over a 3-year period. They ranked each according to wear, marginal adaptation (closeness of fit to the tooth), surface smoothness, wear of opposing teeth, breakage and color match. Amalgam was ranked 14th in overall strength, durability and effectiveness behind 11 composite filling materials and two porcelain/ceramic materials. Ten of the top 11 materials were composites. The study also showed that recurrent decay and root canal therapy did not happen often enough on all materials combined to even be considered as significant.[1]
Nonetheless, to this day, the FDA and American Dental Association (ADA) insist that composite resins are inferior to amalgam because they amalgams wear faster, have more recurrent decay and may increase the need for root canals. They still assert that “Dental amalgam fillings are strong and long-lasting, so they are less likely to break than some other types of fillings.”[2] The Provo study, conducted over 25 years ago, demonstrated that all of their claims are untrue.
A recent study conducted on over 76,000 patients confirmed this finding.[3] Further support is derived from a large retrospective cohort study that included 58 dental clinics with 440 dental units to examine failed dental restorations (650,000 patients). Failures in amalgam (17%) versus composite resin restorations (12%) between 2014 and 2021 clearly indicate that composite is superior to amalgam.[4]
Banning amalgam fillings would not only address associated health risks but also improve dental outcomes and reduce long-term costs. Amalgam requires removal of healthy tooth structure and weakens teeth, often leading to cracks, root canals, or extractions.[5] Composite resin fillings, made of quartz or silicon powder in a resin matrix, are superior.[6]
All dental schools teach composite placement, often dedicating more time to it than amalgam—some no longer teach amalgam at all. Composite is the preferred restoration method, making technical concerns minimal.[7]
Cost is not a barrier. Dr. Graeme Munro-Hall’s report for the World Alliance for Mercury-Free Dentistry shows no price difference between amalgam and mercury-free alternatives (both around $0.50 per filling).[8] With rising mercury prices since the Minamata Convention, amalgam is expected to become more expensive, not to mention the added environmental and health costs.
- “Clinicians Report | Gordon J. Christensen,” Clinician’s Report, 1994, https://www.cliniciansreport.org/. ↑
- Center for Devices and Radiological Health, “Dental Amalgam – White Paper: FDA Update/Review of Potential Adverse Health Risks Associated with Exposure to Mercury in Dental Amalgam,” WebContent, accessed January 9, 2019, https://www.fda.gov/medicaldevices/productsandmedicalprocedures/dentalproducts/dentalamalgam/ucm171117.htm. ↑
- Mark Laske et al., “Longevity of Direct Restorations in Dutch Dental Practices. Descriptive Study out of a Practice Based Research Network,” Journal of Dentistry 46 (March 2016): 12–17, https://doi.org/10.1016/j.jdent.2016.01.002. ↑
- Guy Tobias et al., “Survival Rates of Amalgam and Composite Resin Restorations from Big Data Real-Life Databases in the Era of Restricted Dental Mercury Use,” Bioengineering (Basel, Switzerland) 11, no. 6 (June 7, 2024): 579, https://doi.org/10.3390/bioengineering11060579. ↑
- Tobias et al. ↑
- Laske et al., “Longevity of Direct Restorations in Dutch Dental Practices. Descriptive Study out of a Practice Based Research Network.” ↑
- Asher Zabrovsky et al., “Next Generation of Dentists Moving to Amalgam-Free Dentistry: Survey of Posterior Restorations Teaching in North America,” European Journal of Dental Education 23, no. 3 (2019): 355–63, https://doi.org/10.1111/eje.12437; C. D. Lynch, R. J. McConnell, and N. H. Wilson, “Posterior Composites: The Future for Restoring Posterior Teeth?,” Prim Dent J 3 (May 2014): 49–53; Elham T. Kateeb and John J. Warren, “The Transition from Amalgam to Other Restorative Materials in the U.S. Predoctoral Pediatric Dentistry Clinics,” Clinical and Experimental Dental Research 5, no. 4 (2019): 413–19, https://doi.org/10.1002/cre2.196; Katariina Ylinen and Göran Löfroth, “Nordic Dentists’ Knowledge and Attitudes on Dental Amalgam from Health and Environmental Perspectives,” Acta Odontologica Scandinavica 60, no. 5 (January 1, 2002): 315–20, https://doi.org/10.1080/00016350260248319. ↑
- Graeme Munro-Hall, “A Comparison of Availability, Affordability, Effectiveness, Risks and Benefits of Dental Materials,” Not sure, chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://minamataconvention.org/sites/default/files/documents/submission_from_organization/WAMFD_Comparison_report_DentalAmalgam.pdf. ↑