Composite vs Amalgam Dental Fillings: Appearance, Durability and How Dentists Choose

The mirror comes out, the light swings in, and the dentist says the sentence nobody enjoys: “There is a cavity on that lower molar.” Then comes the second sentence, the one that often catches people off guard. “We can do a white filling or a silver one. Do you have a preference?” Suddenly you are being asked to weigh up composite vs amalgam fillings with a suction tube in your mouth and roughly ninety seconds to decide.

Most people default to what they have heard: white looks better, silver lasts longer, mercury sounds worrying. Each of those beliefs has a grain of truth wrapped in a layer of folklore.

This explainer separates the two. It walks through what each material is, how it is placed, what the trials show about durability, what the safety evidence actually says, and how a dentist weighs a decision that looks cosmetic from the chair but is mostly about engineering.

What a filling actually does, and why the material matters

A cavity is a hole created when acid from bacteria dissolves the mineral in tooth enamel and the softer dentin underneath. A filling has one job: replace the lost structure so the tooth can chew, stay sealed against bacteria and stop the decay from spreading toward the nerve. MedlinePlus describes fillings as the standard treatment once decay has broken through the enamel surface, because at that point the tooth cannot remineralize on its own.

Every filling faces the same hostile environment. Molars absorb chewing forces many times a day, the mouth swings from ice water to hot coffee within minutes, and a film of bacteria never stops trying to work its way into any gap along the edge. The two most common direct materials meet these challenges in very different ways.

Dental amalgam is a metal alloy made by mixing liquid mercury with a powder of silver, tin and copper; the mercury binds the powder into a paste that hardens in the tooth. Composite resin is a plastic matrix filled with tiny glass or ceramic particles, colored to match enamel and hardened with a blue light. Amalgam relies on physical retention; the cavity is shaped so the set metal is locked in place. Composite is glued, bonded chemically to etched enamel and dentin.

That single difference, locking versus bonding, drives almost everything else: how much healthy tooth is removed, how long the appointment takes, how the filling wears, and how it fails. When you understand it, the composite vs amalgam fillings debate stops being about color and starts being about how each material survives a decade of chewing.

Composite vs amalgam fillings: the differences side by side

Before going deeper, here is the whole comparison in one place. The durability figures come from a Cochrane systematic review of randomized trials in permanent back teeth, and the regulatory notes reflect NHS guidance; everything else describes material properties that are widely accepted in dental textbooks and consumer health resources.

Feature	Composite (tooth-colored)	Amalgam (silver-colored)
What it is	Resin matrix with glass or ceramic filler, light-cured	Alloy of mercury with silver, tin and copper
Appearance	Matched to tooth shade; can stain over years	Metallic gray; may darken with corrosion
How it stays in	Chemical bond to enamel and dentin	Mechanical lock in a shaped cavity
Tooth removal needed	Usually only decayed tissue	Often extra healthy tooth to create undercuts
Moisture during placement	Must be kept dry; saliva weakens the bond	Tolerates some moisture
Chair time	Longer, placed in layers	Shorter, packed in one go
Failure in trials (Cochrane)	Roughly twice the failure and secondary decay rate	Fewer failures over up to seven years
Repairability	New resin can be bonded to old	Usually replaced entirely
Thermal behavior	Close to tooth; slight shrinkage on setting	Expands and contracts more than tooth
Regulatory notes (NHS)	No age restrictions	Avoided under 15, in pregnancy and breastfeeding unless clinically necessary

Two caveats sit behind that table. The trial data compared amalgam with composites from an earlier generation, so modern resins may perform better than the numbers suggest. And the regulatory limits on amalgam are precautionary, driven mainly by environmental mercury targets rather than by evidence of harm to patients, a distinction that matters when you read the safety sections below.

How is a composite filling placed?

The appointment starts the same way for either material. Mayo Clinic describes the routine: the dentist numbs the area, removes the decayed tissue with a drill, air abrasion or laser, and checks that the remaining tooth is sound. From there, the composite pathway becomes a bonding exercise.

A rubber dam, a small sheet of latex or silicone stretched around the tooth, is often placed to keep saliva away. Dryness is not a preference; it is a requirement. Water and saliva sitting on the surface prevent the adhesive from soaking into the tooth, and a weak bond is the most common reason a composite filling later leaks or falls out.

Next comes etching: a mild acid gel roughens the enamel for a few seconds, creating microscopic pores. The gel is rinsed away, the surface is dried to a frosty look, and a thin liquid bonding agent is painted on and light-cured. That layer acts as the glue.

The composite itself is placed in increments, usually no thicker than a couple of millimeters at a time. Each layer is shaped and then hardened with a blue light for a short burst. Layering matters because resin shrinks slightly as it sets; small layers keep that shrinkage from pulling the filling away from the walls of the cavity. On a large molar filling this can mean five or six cycles of place, shape, cure.

Finally the dentist checks the bite with marking paper, adjusts any high spots and polishes the surface smooth so it resists staining and plaque. The filling is fully hard the moment you leave; there is no waiting period before eating, though numbness usually makes a cautious lunch sensible.

How is an amalgam filling placed, and why does it need a different shape?

Amalgam does not stick to teeth. It holds on the way a dovetail joint holds a drawer together: the cavity is carved so that the opening is slightly narrower than the base, and once the metal hardens it cannot slide out. Dentists call these undercuts.

That mechanical logic changes the preparation. After the decay is removed, the dentist may need to extend the cavity into healthy enamel and dentin to create those retentive walls and to reach a minimum depth, since a thin sliver of amalgam fractures under chewing load. For a small cavity, this can mean removing noticeably more tooth than a composite would require. For a large cavity that already has plenty of depth, the difference shrinks.

The alloy arrives as a sealed capsule containing mercury and metal powder. A mixing machine shakes it for a few seconds into a soft, silvery paste. The dentist packs this into the cavity with hand instruments, condensing it firmly to squeeze out excess mercury and eliminate voids, then carves the anatomy of the tooth into the surface before it stiffens. Because it tolerates a little moisture, amalgam is forgiving in deep cavities near the gum line where a perfectly dry field is hard to achieve, which is one reason it stayed popular for back teeth so long.

Amalgam reaches most of its strength over the following hours and continues hardening for about a day. Dentists commonly advise avoiding heavy chewing on a fresh amalgam for the rest of the day, and polishing is sometimes done at a later visit. WHO notes that placement and removal are the moments when mercury vapor release is highest, which is why modern practices use high-volume suction and, increasingly, amalgam separators to capture waste.

White fillings vs silver fillings: how much does appearance really matter?

For a front tooth, the answer is obvious. Nobody wants a gray patch at the edge of a smile, and composite has been the standard for visible teeth for decades. The real debate concerns molars and premolars, the teeth that show only when you laugh or yawn.

Here it helps to be honest about what each material looks like at year one and at year ten. A fresh composite is nearly invisible when the shade is well matched. Over time, resin absorbs pigments from coffee, tea, red wine and tobacco, and the margin where it meets enamel can pick up a faint brown line. Regular polishing slows this but does not stop it. A fresh amalgam is bright silver; over years it dulls and can darken, and the surrounding tooth may take on a grayish cast as corrosion products seep into dentin. Some people also develop a harmless bluish mark on the gum or cheek, an amalgam tattoo, if tiny particles lodge in soft tissue during placement.

Appearance also carries a practical cost in one direction. Because composite mimics tooth color, a leaking margin or new decay beside it is harder for the dentist to spot on a visual check; the gray edge of a failing amalgam is easier to see. Bitewing X-rays help with both, since amalgam is bright white on film and most modern composites contain radiopaque fillers.

Where does that leave the choice? Many dentists treat appearance as a legitimate factor for premolars and the first molars, which are visible in a wide smile, and as a lower priority for second molars at the very back. Patient preference is a valid reason to choose composite. The point is to weigh it against durability rather than assume it costs nothing.

How long do composite fillings last compared with amalgam?

This is where evidence rather than opinion should lead, and the best evidence is a Cochrane systematic review that pooled randomized trials comparing direct composite with amalgam in permanent back teeth. The trials followed several thousand fillings for up to seven years. Composite fillings failed roughly twice as often as amalgam over that period, and the rate of secondary decay, new cavities forming at the edge of the filling, was also roughly double. Fracture rates of the filling itself did not differ meaningfully.

The review authors were careful about what those numbers mean. The trials were conducted with composites and bonding systems that predate current products; adhesives and filler technology have improved since. The included participants were largely children and adolescents, not adults with heavy bites or gum recession. And the overall quality of evidence was rated low, so the direction of the effect is fairly convincing while the precise size is not.

Consumer health guidance reflects that picture. Cleveland Clinic notes that fillings of any type can serve for many years with good care and that amalgam has historically been regarded as the more durable option for large load-bearing fillings, while composite has closed the gap in small and medium cavities. Ranges you will see quoted online, often five to ten years for composite and ten to fifteen for amalgam, are averages drawn from practice-based studies rather than promises, and individual fillings routinely outlast or fall short of them.

What shortens the life of either material is more predictable than the material itself: grinding at night, a diet heavy in sugar or acid, a large filling with thin remaining tooth walls, and gaps in daily cleaning. A well-placed composite in a person who flosses will usually outlive a hastily placed amalgam in someone who does not.

Are composite fillings safe?

Yes, for the overwhelming majority of people, and the question deserves a fuller answer than a single word because composite has its own chemistry to consider.

Composite resins are built on methacrylate monomers, small molecules that link together into a hard plastic when the blue light hits them. A common concern involves bisphenol A, or BPA, an industrial chemical used in some plastics. Most dental composites do not contain BPA as an ingredient, but some are made from derivatives of it, and trace amounts can be released in the first hours after placement, mainly from the thin uncured layer on the surface. Dentists typically remove that layer by polishing and rinsing, and measured exposures fall rapidly to background levels. Mainstream reviews have not linked composite fillings to health harm from BPA at the amounts involved.

Allergy is possible but uncommon. A small number of people react to acrylate monomers with contact sensitivity, more often affecting dental staff who handle uncured material daily than patients who receive the hardened product. If you have a known acrylate allergy, say so before treatment.

The more everyday safety issue is technical rather than toxic. Because composite must be bonded in a dry field, a poorly sealed margin can allow bacteria underneath, leading to sensitivity or hidden decay. That is a failure of placement conditions, not evidence that the material is harmful, and it is the main reason dentists sometimes steer away from composite in cavities they cannot keep dry.

Composite is also the material used for children under 15, during pregnancy and while breastfeeding in health systems that follow NHS guidance, precisely because it carries no mercury question. That regulatory preference is often read as proof that composite is the “healthier” choice. It is more accurate to say composite avoids a specific precaution that applies to amalgam.

Is the mercury in amalgam fillings dangerous?

This is the question underneath most searches for composite vs amalgam fillings, so it deserves precision.

Amalgam contains about half its weight as mercury, bound into an alloy with silver, tin and copper. Once set, the metal releases very small amounts of mercury vapor, mostly during chewing, grinding or brushing, and more briefly during placement and drilling out. WHO lists dental amalgam among the everyday sources of low-level mercury exposure alongside certain fish and some skin-lightening products, and it distinguishes these from the high-dose occupational and environmental exposures that cause recognized mercury poisoning.

What has the evidence found in patients? Large randomized trials in children, the same trials that fed the Cochrane durability review, measured kidney function, memory, attention and nerve conduction over several years and found no differences between children given amalgam and those given composite. Population studies in adults have not shown a consistent link between the number of amalgam fillings and neurological or kidney disease. Mainstream health bodies continue to regard existing amalgam fillings as safe for the general population.

So why are amalgam restrictions tightening? Two reasons. The first is precaution for groups considered more vulnerable to any mercury exposure: developing children and the fetus, hence the NHS guidance to avoid amalgam under 15 and in pregnancy or breastfeeding unless clinically necessary. The second is environmental. Mercury from dental waste and cremation enters water and air, and the international Minamata Convention, which WHO supports, commits countries to phasing down amalgam use. Those are public health and pollution decisions, not a finding that your existing filling is poisoning you.

A practical consequence follows: removing sound amalgam simply to be rid of mercury exposes you to a brief vapor spike during drilling and sacrifices tooth structure. Mainstream guidance does not recommend it unless the filling is failing or the patient has a documented allergy.

Who usually gets composite, who usually gets amalgam, and who is asked to wait

Dentists rarely apply a single rule. A pattern does emerge, though, from guidance and from how the materials behave.

Composite is the usual choice for front teeth and any surface that shows in a smile, for small to medium cavities in back teeth where a dry field is achievable, and for cavities where preserving healthy tooth matters because the walls are already thin. It is also the default for children under 15, pregnant patients and those who are breastfeeding under NHS-style rules, and for anyone with a confirmed metal allergy.

Amalgam is still considered for large cavities on molars that bear heavy chewing forces, especially where the cavity extends below the gum line and saliva or blood cannot be reliably excluded. Patients who grind their teeth heavily, or who have several large fillings that have repeatedly failed in composite, may be offered amalgam for its tolerance of harsh conditions. Deep cavities in patients with limited ability to sit still for a long appointment, including some with disabilities or dental anxiety, sometimes suit the shorter amalgam procedure.

Some people are asked to wait or to consider a different route altogether. A cavity that has reached the nerve is not a filling case; it needs root canal treatment or extraction. A tooth with so little structure left that any filling would be a stopgap is often better served by a crown or an onlay, an indirect restoration made in a laboratory. Active gum disease is usually stabilized first, since bleeding tissue undermines both bonding and the seal at the margin. And where early decay has not yet broken the enamel surface, Mayo Clinic notes that fluoride treatment and monitoring may be preferred to any filling at all.

Whatever the pattern suggests, the decision rests with the dentist examining the tooth, who sees details no general rule can capture.

How dentists choose between composite and amalgam fillings

Watch a dentist decide and you will notice it happens in seconds, but the reasoning is layered. Here is how it typically unfolds.

First, location and visibility. A front tooth or a premolar edge that shows in photographs pushes toward composite immediately.

Second, size and depth. The dentist estimates how much tooth will remain after decay is removed. A small cavity with thick walls favors composite because bonding preserves structure. A very large cavity may favor amalgam, or may prompt the bigger conversation about a crown.

Third, moisture. Can the tooth be isolated with a rubber dam or cotton rolls and suction? If the cavity dips below the gum, if the tongue and cheek crowd the field, or if the patient struggles with the dam, reliable bonding becomes doubtful and amalgam’s forgiveness becomes attractive.

Fourth, bite forces. Worn, flattened teeth or a history of cracked fillings suggest a heavy bite, which stresses any restoration and historically has favored metal.

Fifth, the patient. Age, pregnancy, allergies, dental anxiety and stated preference all count. The NHS notes that patients can ask for tooth-colored fillings and that the dentist will explain whether the tooth is suitable.

Sixth, the wider history. Someone with many previous fillings and ongoing decay activity has a mouth that will test any material; the dentist may weigh durability more heavily and pair the filling with a prevention plan. Someone with an otherwise healthy mouth and one small cavity has more freedom to choose on appearance.

The best way to read this is that the two materials are not rivals for every tooth. They are tools with overlapping but distinct ranges, and a good decision matches the tool to the specific hole, the specific bite and the specific person in the chair.

What the first days and weeks after a filling usually look like

Numbness wears off over the first few hours. Until it does, chewing risks biting the cheek or tongue, so soft food on the other side of the mouth is the usual advice. Amalgam continues to harden for about a day, and dentists commonly suggest avoiding sticky or very hard foods on that side until the next day; composite is fully set at the chair, so eating is limited only by numbness.

Sensitivity to cold, sweet or pressure is common with either material and usually fades. Cleveland Clinic describes this settling over days to a few weeks as the inflamed nerve inside the tooth calms down. Deeper fillings tend to be more sensitive for longer because less dentin insulates the nerve. Composite carries an extra cause: if the resin shrank slightly on setting or the bond is imperfect, tiny fluid movements under the filling can trigger sharp twinges on biting. Amalgam carries its own: metal conducts temperature well, so cold drinks may register more sharply for a while.

A filling that feels “high” when you close your teeth together is worth mentioning promptly. Even a fraction of a millimeter can bruise the ligament around the tooth and create an ache that resolves quickly once the dentist adjusts the surface. This is a two-minute fix, not a complication.

Beyond the first month, the filling should be unnoticeable. Composite may pick up stains over years and can be repolished at routine visits. Amalgam may darken. Both are checked at regular examinations, visually and with periodic X-rays, for marginal breakdown or new decay. Daily cleaning is the single largest factor in how long either lasts: brushing twice daily with fluoride toothpaste and cleaning between teeth, exactly the routine MedlinePlus recommends for preventing decay in the first place.

What are the downsides of composite fillings?

Composite has earned its popularity, and it also has weaknesses that patients rarely hear about while looking at a shade guide.

Technique sensitivity is the biggest. The bond depends on a dry, clean surface, correct etching time, an even adhesive layer and thorough light curing of every increment. Skip or rush any step and the filling may look perfect while leaking underneath. This is why the same material performs differently in different hands and different cavities, and why the Cochrane review found composite’s secondary decay rate about double that of amalgam.

Shrinkage stress follows. Resin contracts a little as it sets, pulling on the bonded walls. In a small cavity this is negligible; in a large one it can create a microscopic gap or postoperative sensitivity. Layering reduces the effect but cannot abolish it.

Wear and staining come next. Modern composites resist wear well, but in a heavy grinder they wear faster than metal, and the surface gradually roughens, holding pigment and plaque. A composite that looked seamless can show a brown margin after several years.

Chair time is longer, which matters for young children, people with anxiety or gag reflexes, and anyone who struggles to keep still with a rubber dam in place.

Detection is harder. Because it matches enamel, early failure at the margin is less visible on inspection, so problems may be caught later than with the obvious gray edge of amalgam.

Against all this stands a genuine advantage that offsets several downsides: repairability. When a composite chips or a margin stains, the dentist can often roughen the surface and bond fresh material without removing the whole filling, preserving tooth each time. Amalgam usually has to come out entirely, and each replacement enlarges the cavity. Over a lifetime, that difference in how failures are managed can matter as much as how often they occur.

What people often get wrong about composite vs amalgam fillings

Some beliefs circulate so widely that they sound like settled fact. Several do not survive a look at the evidence.

“White fillings are healthier.” Composite avoids mercury, and that is a real distinction for children and in pregnancy under precautionary rules. For a healthy adult, trials have not shown health differences between the two, while durability evidence favors amalgam in large back-tooth fillings. Healthier is not the right word; different trade-offs is.

“Old silver fillings should be removed to detox.” Removal releases more mercury vapor than leaving the filling alone, and it sacrifices sound tooth. Mainstream guidance reserves replacement for fillings that are failing, decayed or causing a documented allergic reaction.

“Composite fillings always fall out early.” The trials that found higher composite failure used older materials and mostly followed children. Well-bonded modern composites in small and medium cavities routinely last many years. The material is more demanding, not doomed.

“Amalgam causes cracked teeth.” Amalgam expands and contracts with temperature more than tooth does, and large old amalgams are found in many cracked molars. But those teeth were already weakened by the large cavity and the undercut preparation; the metal is a contributor, not a lone culprit. Large composites in thin-walled teeth crack too.

“A filling is a permanent fix.” No filling lasts forever. Every restoration has a service life, and the tooth around it continues to age, wear and face acid. Regular checks and prevention protect the investment.

“You can’t have amalgam anymore.” Use is being phased down under the Minamata Convention that WHO supports, and restricted for certain groups, but it remains a legitimate, regulated material for adults where a dentist judges it the better option.

Questions to ask your care team before choosing a filling

The conversation about material often lasts less than a minute. A few questions can turn it into a genuinely informed choice without taking much longer.

• How large is this cavity, and how much healthy tooth will remain after the decay is removed? The answer tells you whether preserving structure or maximizing strength matters more.
• Can this tooth be kept reliably dry during the procedure? If not, ask how that affects the choice between composite and amalgam.
• Would this tooth be better served by a crown or an onlay rather than a direct filling? Very large cavities sometimes need indirect restorations to avoid repeat failures.
• Do I show signs of grinding or a heavy bite, and how would that influence the material or the need for a night guard?
• If the filling chips or stains later, can it be repaired rather than replaced?
• How will you check this filling at future visits, and how often do you recommend X-rays for someone with my decay history?
• Are there reasons in my medical history, such as pregnancy, breastfeeding or a known metal or acrylate allergy, that rule one material in or out?
• What sensitivity should I expect in the first weeks, and at what point should I come back?
• Is there early decay elsewhere that could be managed with fluoride and monitoring instead of a filling?
• What can I change day to day so this filling and the teeth around it last as long as possible?

Notice that none of these questions is about which material is “better.” They are about your tooth, your mouth and your habits. A dentist who answers them is giving you the same reasoning they use themselves, and the final choice, made together, is far more likely to be one you are content with years later when the filling is still quietly doing its job.

When to call your doctor or dentist

Mild sensitivity to cold or sweet in the first days after a filling is expected and usually fades over a few weeks. Certain signs are different and warrant a prompt call rather than waiting for the next routine appointment.

• Pain that is severe, throbbing or wakes you at night, or pain that worsens rather than improves after the first week. This can signal that the nerve inside the tooth is inflamed beyond what settles on its own.
• Sharp pain on biting that persists beyond the first few days, which may point to a high spot, a crack in the tooth or a gap under the filling.
• Sensitivity lasting more than a few weeks without easing, or new sensitivity that appears months after placement.
• Swelling of the gum, face or jaw, a bad taste, a pimple-like bump on the gum near the tooth, or fever. These suggest infection and should be assessed the same day; MedlinePlus describes dental abscess as a condition needing urgent treatment.
• A filling that feels loose, has visibly chipped, or has come out. An exposed cavity is vulnerable to further decay and fracture.
• A rough or sharp edge that repeatedly catches your tongue or cheek, or floss that shreds at the filling margin.
• Signs of an allergic reaction after placement, such as itching, rash or swelling in or around the mouth, which are rare with either material but need review.

Seek urgent medical care, not just a dental appointment, if facial swelling spreads toward the eye or neck, if you have difficulty swallowing or breathing, or if fever comes with a spreading infection. These are emergencies.

Whatever the material in your tooth, the people who placed it want to hear about problems early. Small adjustments made in the first weeks prevent most of the larger issues that appear later, and every decision about repair or replacement belongs with the clinician who can examine the tooth directly.

Frequently asked questions

Are composite fillings safe?

Yes, composite fillings are considered safe for the general population. They are built from methacrylate resins and glass filler hardened by light. Trace amounts of chemicals such as BPA derivatives can be released in the first hours after placement, but exposures fall quickly and have not been linked to harm in mainstream reviews. Acrylate allergy is rare. The main practical risk is a poor bond in a wet field, which leads to leakage rather than toxicity.

Are composite fillings healthier than amalgam?

Not in a way that trials have been able to measure for healthy adults. Composite avoids mercury, which is why it is preferred for children under 15 and during pregnancy or breastfeeding under precautionary NHS guidance. But randomized trials comparing the two materials in children found no differences in kidney, memory or nerve outcomes. Each material carries different trade-offs; neither has been shown to improve overall health.

How long do composite fillings last?

It varies widely with size, location, bite and daily care. Consumer guidance commonly quotes several years to a decade or more for composite, with amalgam historically lasting longer in large back-tooth fillings. The Cochrane review supports that direction, finding roughly double the failure rate for composite over follow-up of up to seven years, using older materials. A small, well-bonded composite in a well-cared-for mouth often outlasts those averages.

What are the main downsides of composite fillings?

Composite is technique-sensitive: it needs a dry field, careful etching and thorough curing, so results depend heavily on placement conditions. It shrinks slightly as it sets, wears faster than metal under heavy grinding, picks up stains over years and takes longer to place. Early failure at the margin is also harder to spot visually. Its offsetting strength is repairability, since fresh resin can often be bonded to the old without full replacement.

Are composite fillings worth it for back teeth?

Often yes, particularly for small to medium cavities where a dry field is achievable and preserving tooth structure matters. For very large molar cavities under heavy bite forces, or where the cavity sits below the gum and cannot be kept dry, a dentist may judge amalgam or a crown the sounder choice. “Worth it” depends on the specific tooth, and the treating dentist’s assessment of size, moisture and bite should guide the answer.

Should I have my old amalgam fillings replaced with white ones?

Mainstream guidance does not recommend replacing sound amalgam fillings simply because they contain mercury. Drilling out amalgam releases more mercury vapor than leaving it in place and removes healthy tooth each time. Replacement is appropriate when a filling is fractured, leaking, decayed underneath or causing a documented allergic reaction, or when appearance genuinely matters to you and your dentist confirms the tooth can support a new bonded restoration.

Why do white fillings sometimes hurt when biting afterward?

Biting pain after a composite filling usually has one of two causes. The filling may be slightly high, bruising the ligament around the tooth; a quick adjustment fixes this. Or the resin may have shrunk slightly on setting, leaving a microscopic gap where fluid movement triggers a sharp twinge. Mild sensitivity typically settles over days to a few weeks. Pain that persists or worsens should be checked by your dentist.

Is amalgam still used in pregnancy or for children?

Under NHS guidance, amalgam is not used for children under 15 or for patients who are pregnant or breastfeeding unless the dentist considers it clinically necessary. This reflects precautionary limits on mercury exposure in developing children and the fetus, alongside international commitments to phase down amalgam under the Minamata Convention. Composite or other mercury-free materials are the usual alternatives in these groups.

Can a composite filling be repaired instead of replaced?

Frequently, yes. If a composite chips, wears or develops a stained margin, the dentist can often roughen the existing surface and bond fresh resin to it, preserving the underlying tooth. Amalgam generally cannot be added to in the same way and is usually removed entirely when it fails, enlarging the cavity each time. Whether repair is suitable depends on the extent of the damage and the condition of the tooth.

White fillings vs silver fillings: which is easier to check for new decay?

Silver fillings are easier to inspect visually because a failing margin shows as a dark line against enamel. White fillings blend in, so early leakage or decay at the edge can be less obvious on a glance. Both are checked with periodic bitewing X-rays, on which amalgam appears bright white and most modern composites contain radiopaque fillers that also show up, allowing hidden decay beneath either material to be detected.

References

• WHO Fact Sheet: Mercury and health
• Cleveland Clinic: Dental fillings
• MedlinePlus: Tooth decay

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.