Silver Tooth Filling: Pros, Cons & Alternatives

A silver tooth filling is made from dental amalgam, a mixture of metals that has been used to restore teeth since the 1800s. Despite the common name "silver filling," the material actually contains several metals:

• Silver (~40%) – provides strength and durability


• Tin (~30%) – helps the material set properly


• Copper (~15%) – adds strength and corrosion resistance


• Mercury (~50% by weight) – binds the metals together into a workable paste


• Small amounts of zinc, palladium, or indium in some formulations

Yes, amalgam contains mercury—and that's the primary reason these fillings generate controversy. We'll address the safety question in detail below.

How amalgam fillings work: Your dentist mixes the metal powder with liquid mercury to create a soft, putty-like material. This is packed into the cleaned-out cavity, where it hardens over the next 24 hours into an extremely durable restoration. Unlike composite (white) fillings that are hardened instantly with a curing light, amalgam fillings need time to fully set.

Silver fillings have remained in use for so long because they offer genuine advantages that newer materials still struggle to match in certain situations:

Exceptional durability
Amalgam fillings routinely last 10-15 years, and many last 20 years or more. They withstand heavy chewing forces better than any other direct filling material, making them ideal for large cavities in back teeth (molars) that bear significant bite pressure.

Lower cost
Silver fillings are typically 30-50% less expensive than composite fillings. The material itself is cheaper, and the placement technique is faster—meaning less chair time and lower labor costs. For patients paying out-of-pocket, the savings can be significant.

Less technique-sensitive
Amalgam is more forgiving during placement. It's less affected by moisture contamination, which matters because keeping a tooth perfectly dry during a filling can be challenging, especially for cavities below the gum line or far back in the mouth. This means amalgam fillings are less likely to fail due to placement technique.

Proven track record
With over 150 years of clinical use and hundreds of millions of fillings placed worldwide, amalgam has an extensive safety and performance history. No other dental filling material has been studied as thoroughly.

Self-sealing properties
Over time, the corrosion products from amalgam actually fill in microscopic gaps at the filling's edges. This "self-sealing" property reduces the risk of bacteria leaking under the filling—a common cause of recurrent decay.

Despite their strengths, silver fillings have meaningful drawbacks that explain why many dentists and patients now prefer alternatives:

Appearance
This is the most obvious disadvantage. Silver fillings are highly visible—they start as a shiny silver color and darken to gray or black over time. For any tooth that shows when you smile or talk, amalgam is a poor cosmetic choice.

Mercury content concerns
Although major health organizations consider amalgam safe for most patients, the mercury content is a legitimate concern for some people. We address this in detail in the next section.

More tooth removal required
Amalgam doesn't bond to tooth structure—it's held in place by the shape of the cavity. Your dentist must create undercuts (wider at the bottom than the top) so the filling locks in mechanically. This means removing more healthy tooth structure than a bonded composite filling would require.

Temperature sensitivity
Metal expands and contracts with temperature changes more than tooth enamel does. Over years of drinking hot coffee and cold water, this repeated expansion and contraction can create microfractures in the surrounding tooth. This is one reason amalgam-filled teeth sometimes crack years later.

Galvanic response
If you have amalgam fillings near gold crowns or other metal restorations, the different metals can create a mild galvanic current (like a tiny battery in your mouth). This can cause a sharp, unpleasant metallic taste or zinging sensation, though it's uncommon.

Tooth discoloration
Amalgam can stain the surrounding tooth structure over time, giving the tooth a grayish tint that persists even if the filling is later replaced with composite. This staining is purely cosmetic but can be frustrating.

Environmental concerns
Mercury from dental amalgam can enter the environment through waste water and cremation. Many dental offices now use amalgam separators to capture mercury waste, and some countries have restricted or banned amalgam use for environmental reasons.

This is the question most patients want answered, and the evidence is extensive:

What major health organizations say:

The American Dental Association (ADA), FDA, World Health Organization (WHO), and Centers for Disease Control (CDC) all consider dental amalgam safe for adults and children age 6 and older. Their position is based on decades of research involving millions of patients.

The science behind the safety assessment:

Mercury in amalgam is not the same as the mercury in fish (methylmercury). Dental amalgam contains elemental mercury, which behaves differently in the body. When combined with the other metals in amalgam, the mercury forms a stable compound that releases only very small amounts of mercury vapor over the life of the filling.

Studies measuring mercury levels in people with amalgam fillings consistently show levels well below those associated with health effects. The amount of mercury vapor released from fillings is a tiny fraction of what people absorb from food, water, and air in daily life.

Who should consider alternatives:

Despite the overall safety assessment, some groups may want to avoid amalgam:

• Pregnant or nursing women – as a precaution, many dentists recommend composite fillings during pregnancy


• Children under 6 – developing bodies may be more sensitive to mercury exposure


• People with mercury allergies – rare but real; symptoms include oral lesions and skin rashes


• People with kidney disease – impaired mercury elimination may increase risk


• People who strongly prefer to avoid mercury – patient comfort and peace of mind matter

The FDA's 2020 update:

In 2020, the FDA recommended that certain high-risk groups (pregnant women, nursing mothers, children under 6, and people with pre-existing neurological disease or impaired kidney function) avoid amalgam fillings when possible and use alternatives. This was a precautionary recommendation, not a finding of harm.

Important: If you have existing silver fillings that are in good condition, removing them unnecessarily exposes you to more mercury (from drilling out the amalgam) than leaving them in place. Don't remove functional amalgam fillings solely out of mercury fear without consulting your dentist about the risks and benefits.

The choice between amalgam and composite is the most common filling decision patients face. Here's how they compare:

Durability

• Amalgam: 10-15+ years, excellent for large cavities in molars


• Composite: 5-10 years on average, improving with newer formulations


• Winner: Amalgam, especially for large restorations on back teeth

Appearance

• Amalgam: Silver/gray, highly visible, darkens with age


• Composite: Tooth-colored, blends with natural teeth, virtually invisible


• Winner: Composite, by a wide margin

Cost

• Amalgam: $75-$200 per filling (without insurance)


• Composite: $150-$400 per filling (without insurance)


• Winner: Amalgam, typically 30-50% cheaper

Tooth preservation

• Amalgam: Requires more drilling to create mechanical retention


• Composite: Bonds directly to tooth, preserving more healthy structure


• Winner: Composite, removes less natural tooth

Sensitivity

• Amalgam: May cause temperature sensitivity due to metal conductivity


• Composite: Can cause post-placement sensitivity that usually resolves


• Winner: Tie – both can cause temporary sensitivity

Longevity in high-stress areas

• Amalgam: Excellent under heavy chewing forces


• Composite: More prone to wear and fracture under heavy load


• Winner: Amalgam for large cavities in molars

When amalgam is the better choice:

• Large cavities in back teeth


• Teeth difficult to keep dry during filling placement


• Budget is a primary concern


• The tooth isn't visible when you smile

When composite is the better choice:

• Any visible tooth


• Small to medium cavities


• You want to preserve maximum tooth structure


• You prefer to avoid mercury


• Cosmetic appearance matters to you

Silver amalgam fillings are among the most affordable dental restorations:

Without insurance:

• Small amalgam filling (one surface): $75-$150


• Medium amalgam filling (two surfaces): $100-$200


• Large amalgam filling (three or more surfaces): $150-$300

With dental insurance:
Most dental insurance plans cover amalgam fillings at 80-100% after your deductible. Many plans that cover composite fillings on front teeth will only cover the amalgam price for back teeth, meaning you'd pay the difference if you choose composite for a molar.

Cost comparison with other filling materials:

• Amalgam: $75-$300


• Composite (white): $150-$400


• Gold inlay/onlay: $500-$4,500


• Porcelain inlay/onlay: $500-$2,500

Why price varies:

• Geographic location (urban vs. rural, region of the country)


• Size of the cavity (more surfaces = higher cost)


• Dentist's experience and practice type


• Whether sedation or additional procedures are needed

Insurance tip: If your insurance covers only amalgam pricing for back teeth and you want composite, ask your dentist's office about the "upgrade" cost. Many patients find the out-of-pocket difference is only $50-$100—worth it for a tooth-colored result.

This is one of the most common questions patients ask. The answer depends on the condition of the filling, not just its appearance:

Replace silver fillings when:

• The filling is cracked, broken, or has visible gaps – bacteria can enter gaps between the filling and tooth, causing decay underneath


• There's decay around or under the filling – your dentist may detect this on X-rays before you notice symptoms


• The tooth has fractured – old amalgam fillings can contribute to tooth fractures over time


• You're experiencing pain or sensitivity – this may indicate the filling is failing


• The filling is significantly worn down – reducing its ability to protect the tooth

Think carefully before replacing silver fillings if:

• The filling is intact and functioning well – replacing a good filling involves drilling, which removes healthy tooth structure and carries a small risk of nerve damage


• Your only reason is cosmetic – weigh the cosmetic benefit against the biological cost of more drilling


• Your only reason is mercury concern – removing amalgam releases significantly more mercury vapor than leaving it in place; if you're concerned about mercury, leaving a functional filling alone is actually the safer choice


• The tooth would need a crown after removal – large amalgam fillings may not be easily replaced with composite; removal might require a crown, increasing cost significantly

The replacement process:
When a silver filling does need replacement, your dentist will use a rubber dam and high-volume suction to minimize amalgam particle and vapor exposure. The old filling is drilled out, any new decay is removed, and a new restoration (usually composite or a crown for larger teeth) is placed.

What to expect: Some sensitivity for 1-2 weeks after replacement is normal. If the original filling was large, your dentist may recommend a crown instead of a new filling for better long-term protection.

Amalgam use is declining worldwide, driven by cosmetic preferences, environmental concerns, and improving alternatives:

Global trends:

• Norway, Sweden, and Denmark have banned amalgam entirely


• The European Union banned amalgam for children under 15 and pregnant/breastfeeding women in 2018, with broader phase-down plans


• Japan rarely uses amalgam, favoring other materials


• The United States and Canada continue to consider amalgam safe but have seen significant declines in use

Why amalgam isn't disappearing faster:
Despite the trend toward composite, amalgam remains valuable in specific situations—particularly for large restorations in back teeth, in areas with limited access to modern dental technology, and for patients on tight budgets. No alternative material yet matches amalgam's combination of durability, ease of placement, and affordability.

Emerging alternatives:

• Bulk-fill composites – newer composite formulations designed to be placed in larger increments, closing the gap with amalgam for bigger cavities


• Glass ionomer cements – release fluoride and bond to tooth, useful for specific situations


• Bioactive materials – next-generation materials that interact with tooth structure to promote remineralization

For now, both amalgam and composite remain valid choices, and the best filling material depends on your specific situation, tooth location, cavity size, and personal preferences.