Oral health care must evolve to support planetary health.
For nearly a third of humanity, tooth decay is not a minor inconvenience but a persistent, often untreated burden — one that has long been addressed with a material, dental amalgam, that carries its own quiet cost to both people and planet. The World Health Organization has now issued comprehensive guidelines charting a different path: mercury-free, less invasive approaches to preventing and treating dental caries that are clinically sound, environmentally responsible, and designed to reach the most vulnerable. This is not merely a technical revision to dental practice — it is a recognition that how we care for human bodies cannot be disentangled from how we care for the world those bodies inhabit.
- Tooth decay silently afflicts 2.7 billion people, often beginning in early childhood and falling hardest on those with the least access to care.
- Dental amalgam — the decades-long standard of treatment — contains mercury that harms ecosystems and poses ongoing risks to patients and the dental workers who handle it daily.
- WHO's new guidelines present clinically validated, affordable alternatives: fluoride varnish, silver diamine fluoride, and mercury-free restorations that match or outperform the old standard without the environmental toll.
- Vulnerable populations — children, pregnant women, those with allergies — receive specific protections under the guidelines, including limits on exposure to BPA derivatives found in some composite materials.
- The path from guideline to practice is steep: governments must rewrite policies, dental schools must retrain faculty, and front-line workers in under-resourced clinics must gain access to new materials and methods before 2030.
- A global launch webinar on World Oral Health Day, March 19, 2026, will formally introduce the guidelines — but the deeper transformation will be measured in clinics, curricula, and communities far beyond that moment.
Tooth decay is the most common noncommunicable disease on Earth, touching nearly a third of humanity and often beginning before a child turns five. For generations, the answer was dental amalgam — effective, familiar, and laced with mercury that accumulates in ecosystems and poses risks to patients and dental workers alike. The World Health Organization has now moved to change that, releasing guidelines that make the case, with comprehensive scientific evidence, that mercury-free dentistry is not a compromise — it is an upgrade.
The guidelines offer eight core recommendations spanning prevention, early intervention, and restoration. Fluoride varnish can stop early decay without drilling. Silver diamine fluoride — a compound with over a century of safe use — can halt moderate lesions with twice-yearly application. When fillings are needed, glass ionomer cements and resin-based composites replace amalgam entirely. All alternatives are tested, affordable, and free of mercury. The guidelines also address safety with unusual specificity, flagging risks for children, pregnant women, and those with allergies, and recommending limits on BPA-derivative exposure from some composite materials.
But publishing a guideline is only the beginning. Health ministries must embed mercury-free approaches into national policy. Dental schools must retrain faculty and rewrite curricula. Community health workers in rural clinics — often the only point of care for underserved populations — must have both the materials and the training to use them. The WHO frames this as a necessary step toward universal oral health coverage by 2030, aligned with the Global Oral Health Action Plan and the broader recognition that health systems must operate within planetary limits.
Gaps remain. Long-term data on some interventions is still sparse. Occupational risks for workers using new materials need further study. Environmental monitoring of mercury-free disposal is still developing. The WHO has called for global collaboration to close these gaps. On March 19, 2026 — World Oral Health Day — the organization will formally launch the guidelines to the world. The harder work of changing practice across thousands of clinics will follow.
Tooth decay is the most common noncommunicable disease on Earth. It affects 2.7 billion people—nearly a third of humanity—and it often starts before a child's fifth birthday. For decades, the standard response has been to fill cavities with dental amalgam, a material that contains mercury. That mercury leaches into the environment and accumulates in ecosystems. It also poses risks to the people who use it and the dental workers who handle it every day. Now the World Health Organization has released a new set of global guidelines designed to change that calculus entirely.
The guidelines, titled "Environmentally friendly and less invasive oral health care for preventing and managing dental caries," represent the first time the WHO has marshaled comprehensive scientific evidence to show that mercury-free approaches work just as well as the old standard—and work better for the planet. The document draws on systematic reviews of clinical performance, toxicology, cost-effectiveness, and environmental impact. It reflects a growing global commitment to phase out mercury use under the Minamata Convention on Mercury, an international treaty signed by nearly every country on Earth. But it also reflects something simpler: the recognition that oral health cannot be separated from planetary health.
The guideline makes eight core recommendations and two best practice statements. For prevention, it strongly endorses fluoride varnish applied to all teeth, and targeted sealants for children at high risk. For early-stage decay, fluoride varnish can stop the disease in its tracks. For moderate lesions, a twice-yearly application of silver diamine fluoride—a compound that has been used safely in dentistry for over a century—can halt progression without drilling. When restoration is necessary, the guidelines recommend glass ionomer cements and resin-based composites instead of amalgam. All of these alternatives are mercury-free. All have been tested. All are affordable.
The guidelines also attend to safety in ways the old system often did not. They specify protocols for handling resin-based materials to protect both patients and dental workers. They flag special concerns for vulnerable populations: people with allergies, children, adolescents, and pregnant or breastfeeding women. They recommend limiting exposure to BPA derivatives—chemicals found in some composite materials—among these groups. This is not abstract caution. It is the result of asking: who bears the burden of our dental practices, and how do we reduce it?
Implementing these guidelines will require more than publishing a document. Governments and health ministries must integrate mercury-free products and less invasive techniques into national policies. Dental schools must retrain their faculty and rewrite their curricula. Professional associations must update their protocols. Front-line health workers—many of them in rural clinics with minimal resources—must have access to these materials and the training to use them. The guidelines call for all of this, and they also call for something harder: expanding access to oral health care through primary health care systems and community-based delivery models, so that the 2.7 billion people affected by tooth decay can actually receive treatment.
The WHO is framing this as a decisive step toward universal health coverage for oral health by 2030. That is the stated goal of the Global Oral Health Action Plan 2023–2030. It is also aligned with the broader sustainable development agenda—the recognition that health systems must operate within planetary boundaries. Dr. Benoit Varenne, the WHO's Dental Officer, called the guideline "a landmark in global oral health." Dévora Kestel, director of the WHO's Department of Noncommunicable Diseases and Mental Health, put it differently: "Oral health care must evolve to support planetary health."
The guideline also identifies what remains unknown. Long-term effectiveness and cost-effectiveness data are still sparse for some interventions. The occupational exposure risks for dental workers using mercury-free materials need more study. The environmental impact of disposing of these new materials needs monitoring. The WHO is calling for strengthened global collaboration to fill these gaps and drive innovation forward. On March 19, 2026, the organization will host a global launch webinar to mark World Oral Health Day and introduce the guideline formally. The real work—the work of changing practice in thousands of clinics across dozens of countries—will begin after that.
Citas Notables
For the first time, countries have strong evidence showing that safe and less invasive interventions with mercury-free products can effectively prevent, stop and manage dental caries, while providing a more environmentally sustainable alternative to dental amalgam.— Dr. Benoit Varenne, WHO Dental Officer
Oral health care must evolve to support planetary health. By promoting mercury-free products and less invasive clinical procedures, this guideline strengthens both environmental protection and universal access to safe, essential oral health care.— Dévora Kestel, Director a.i., WHO Department of Noncommunicable Diseases and Mental Health
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter that these guidelines exist now, when dentists have been using alternatives to amalgam for years already?
Because guidelines carry weight. A dentist in rural Kenya or Peru can point to WHO evidence and say to their ministry: this is what the world's health authority recommends. It changes what's possible to fund, to train for, to scale. Without the guideline, it's just one dentist's preference. With it, it's policy.
But mercury in dental fillings—isn't that a solved problem in wealthy countries? Why frame it as urgent now?
Solved for some people, yes. But 2.7 billion people still have untreated tooth decay. Most of them live where dental care is scarce and expensive. If the only option offered is mercury amalgam, and it's cheap, they'll take it. The guideline says: there's a better path. It just requires investment and will.
The guidelines mention research gaps. What's actually unknown about these mercury-free alternatives?
Whether they last as long as amalgam in real-world conditions. Whether they're truly cheaper at scale. What happens to dental workers' health over decades of handling resin composites. Whether the environmental cost of manufacturing and disposing of these materials is actually lower. These are not small questions.
Who pushed for this? Was it environmental groups, or did it come from within dentistry itself?
Both. The Minamata Convention created legal pressure to phase out mercury. But the WHO brought together oral health experts, toxicologists, environmental scientists, and health systems people. It wasn't activists writing this—it was the scientific establishment saying: we have the evidence now. We can do better.
What happens if a country reads this guideline and does nothing?
Nothing official happens. But they're signatory to the Minamata Convention. They've committed to phasing down mercury. And now they have a roadmap showing it's possible. The pressure becomes harder to ignore—from their own health workers, from international partners, from their own citizens who understand what mercury does.