Tooth-Colored Fillings

Last updated: November 6, 2026·Reviewed by Soo Jin Kim, DDS

Tooth-colored fillings repair a tooth damaged by decay, or replace an older filling that has worn, cracked or started to leak, with material that blends in with the natural tooth. After the decayed tissue is removed, composite resin, a mix of a plastic resin and fine glass, quartz or silica particles, is bonded into the space, shaped, and hardened with a curing light, usually in a single visit. Glass ionomer, a tooth-colored material that releases fluoride, is another option in some situations, such as decay near the gumline. A small cavity found at a checkup at ConfiDental in Carlstadt can sometimes be filled the same day, with your permission.

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Who you'll see

Soo Jin Kim, DDS

NYU-trained family and cosmetic dentist with a hospital residency at Mount Sinai

Dental degree

DDS, New York University, Omicron Kappa Upsilon honor society

Residency

Icahn School of Medicine at Mount Sinai

More about Dr. Kim

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Dr. Kim on general dentistry

Overview

A filling replaces tooth structure lost to decay. Once the decayed tissue is removed, the space is filled and sealed, and treating a cavity this way can help prevent further damage to the tooth. Tooth-colored fillings also repair minor chips and cracks and replace older fillings, which over the years may weaken, fracture, and leak around the edges, letting bacteria collect and new decay start. Decay around the edges of old fillings, and decay on root surfaces exposed near the gumline, are both common in older adults. Very early decay that has not yet formed a cavity can sometimes be stopped or reversed with fluoride, so not every weak spot on a tooth calls for a filling.

Composite resin can be used on front or back teeth and offers good durability and resistance to fracture in small to mid-size fillings that take moderate chewing pressure. Glass ionomer, made from a glass powder, bonds chemically to the tooth and releases fluoride. It is used especially in baby teeth, on the neck of the tooth near the gumline, and as a liner beneath other fillings, while for large fillings in back teeth it was found more prone to failure than composite or amalgam. The size and location of the cavity shape which material fits. Dental bonding uses the same family of composite materials for cosmetic changes, such as closing gaps or hiding stains on teeth without decay; a filling instead replaces tooth structure lost to decay or to a failed restoration.

Amalgam, the silver-colored alternative, is a mix of metals including mercury, silver, tin and copper. It has been used for generations and is very durable, while tooth-colored materials look more natural. The FDA encourages non-amalgam fillings, where appropriate, for people at higher risk from mercury exposure, including pregnant or nursing women, children, especially those under six, and people with impaired kidney function or pre-existing neurological disease. It does not recommend removing amalgam fillings that are in good condition unless that is considered medically necessary, because removing an intact filling also removes healthy tooth structure. When an older filling of any kind has failed, repairing the damaged part is considered first where it is feasible, since replacing a whole filling sacrifices sound tooth tissue.

A filling can only replace so much of a tooth. When decay is extensive and little tooth structure remains, a crown, a cap fitted over the rest of the tooth, may be needed instead. An inlay or onlay, made in a dental lab from porcelain or gold and then placed, fits a tooth with too much damage to support a filling but not enough to need a crown. If decay reaches the pulp, the soft tissue inside the tooth, or the nerve dies from decay or injury, a filling alone cannot fix the problem, and root canal treatment is recommended before the tooth is restored.

When It's Recommended

A cavity, where decayed tooth tissue needs to be removed and the space restored
Decay around the edges of an existing filling
An older filling that is worn, cracked, fractured, or leaking around the edges
Minor chips and cracks in a tooth
Decay on a root surface exposed near the gumline
Tooth sensitivity traced to a cavity or a worn filling

What are the risks of Tooth-Colored Fillings?

When to avoid

Decay that has reached the pulp, or a nerve that has died from decay or injury, where a filling alone cannot fix the problem and root canal treatment comes first
A tooth with too little structure left to support a filling, where an inlay, onlay or crown is considered instead
Early decay that has not formed a cavity, which can sometimes be stopped or reversed with fluoride instead
An intact amalgam filling in good condition, which the FDA does not recommend removing unless it is considered medically necessary

Possible risks

Temporary tooth sensitivity and gum soreness around the treated tooth, which usually fades within a week or two
Pain when biting if the new filling sits too high, which can be corrected by reshaping the filling
A throbbing toothache, or pain with heat or cold, which can signal that decay reached the pulp or the nerve is damaged, and may require root canal treatment or extraction
Nerve (endodontic) problems, which accounted for almost all composite filling failures in the first year after placement in one pooled analysis
New decay at the edges of the filling, which was more common with composite than with amalgam in trials of back-tooth fillings
Chipping, fracture, or wear of the filling over time
Staining at the edges of the filling, which polishing can often address when it is superficial
Eventual repair or replacement; a pooled analysis of composite fillings in back teeth found average annual failure rates of 1.8% at 5 years and 2.4% at 10 years, mainly from new decay and fracture
A small, temporary rise in bisphenol A (BPA) levels in saliva and urine after resin-based fillings are placed, mostly within 24 to 48 hours, with levels back to pre-treatment values after 2 to 4 weeks

Who needs extra care

A history of allergy to components of composite resin or glass ionomer, which steers the choice toward another filling material
A high risk of tooth decay, which was linked to a significantly higher risk of composite filling failure, so fluoride and other preventive care are weighed alongside the filling
Fillings that span several tooth surfaces, which carry a higher risk of failure than smaller ones
Heavy clenching or grinding of the teeth (bruxism), which has been linked to a higher risk of filling failure

What to Expect During Treatment

We examine your teeth, often with digital dental x-rays, which can show some cavities before they are visible
We numb the tooth and the surrounding gum with a local anesthetic
A dental dam, a thin protective sheet, or another form of isolation keeps the tooth clean and dry
We remove the decayed or damaged tooth tissue, or the old filling, with specialized instruments
A composite shade is chosen to blend with your tooth
An etch and a bonding agent condition the prepared surface
The composite goes in as thin layers or a bulk fill, with a curing light hardening each portion
We shape the filling to the contours of the tooth, then check your bite and adjust it until it feels normal when you close
We polish the filling to smooth any rough edges
A direct filling usually requires only one visit

How do Tooth-Colored Fillings work?

Composite resin holds to the tooth by adhesion. The enamel and dentin are conditioned, either by etching with acid and rinsing or with a self-etching adhesive, and a bonding agent lets the resin lock into the prepared surface.

Composite stays soft until a curing light hardens it, so the filling is shaped on the tooth itself. It can be built up in thin layers, each hardened in turn, or placed as a bulk-fill composite in thicker portions, and a 2026 Cochrane overview found the two approaches had a similarly low risk of failure.
Glass ionomer sets through a chemical reaction within a few minutes and bonds to the tooth through an ion-exchange layer that forms where the material meets the tooth surface. It releases fluoride into the surrounding tooth.
In a deep cavity, softened tissue closest to the pulp may be left in place beneath a sealed filling, or removed in stages, rather than cleared completely in one step. A 2021 Cochrane review found fewer failures, such as exposure of the pulp, with these selective or stepwise approaches than with complete removal in permanent teeth.

Recovery & Aftercare

Eating and drinking can typically resume once the visit is over, and waiting until the numbness wears off helps you avoid accidentally biting the inside of your cheek
Chewing slowly and paying attention while the area is still numb lowers the chance of an accidental bite
Minor sensitivity and gum soreness are common at first and usually fade within a week or two, and over-the-counter acetaminophen or ibuprofen can help
A filling that makes biting uncomfortable can typically be reshaped at a follow-up visit
Contact the dental office right away if the filling breaks, or if you develop severe pain that does not ease with medication, a swollen face or jaw, or fever, chills or other signs of infection
Brushing twice a day with fluoride toothpaste and keeping up with regular cleanings and examinations help protect filled teeth from new decay

Alternative Treatments

Amalgam (silver-colored) fillings, a durable mix of metals that contains mercury and does not match the color of the tooth
Inlays and onlays of porcelain or gold, made in a dental lab, for teeth with too much damage for a filling but not enough to need a crown
Crowns for teeth with extensive decay and little remaining tooth structure
Fluoride treatment for early decay that has not yet formed a cavity
Dental bonding for cosmetic repair of chips, gaps or stains on teeth without decay
Root canal treatment when decay has reached the pulp, followed by a filling or crown
Tooth extraction when a tooth is too damaged to restore

What the Research Says

Dental x-rays may show some cavities before they can be seen just by looking at the teeth[4]
Composite resin is now the preferred filling material because it more closely matches the natural appearance of the tooth[4]
Repairing a filling that has only partly failed preserves existing tooth structure, while replacing the whole filling sacrifices sound tooth tissue[10]
A pooled analysis of 12 long-term studies of composite fillings in back teeth found that a person's risk of decay and the number of tooth surfaces filled played a significant role in how long fillings lasted[14]
The FDA encourages non-amalgam fillings, such as composite resin or glass ionomer, where appropriate for people at higher risk from mercury exposure, including pregnant women and young children[8]

Frequently Asked Questions

What are tooth-colored fillings?

Tooth-colored fillings restore a tooth after decay is removed, or replace an old filling that has worn, cracked or started to leak, using material that blends in with the natural tooth. Most are composite resin, which is bonded into the space and hardened with a curing light, usually in one visit. Glass ionomer, which releases fluoride, is used in some situations, such as decay near the gumline.

Does getting a filling hurt?

The tooth and the surrounding gum are numbed with a local anesthetic before any decay is removed, so the procedure itself is generally not painful. Once the numbness wears off, mild sensitivity and gum soreness around the tooth are common and usually fade within a week or two, and over-the-counter pain relievers can often ease them.

Are tooth-colored fillings safe?

Tooth-colored fillings are generally considered safe. The FDA encourages non-amalgam fillings such as composite resin and glass ionomer, where appropriate, for people at higher risk from mercury exposure, including pregnant women and young children. The risks section covers what to weigh before treatment.

How long do tooth-colored fillings last?

A direct filling is usually placed in a single visit, but fillings do not last a lifetime. How long one lasts depends on the person's risk of decay, how many tooth surfaces it covers, and the forces it takes from chewing and grinding. When part of a filling wears or breaks, it can often be repaired rather than fully replaced, which preserves more of the tooth.

What happens during a filling appointment?

We numb the tooth first, then remove the decay or old filling and keep the tooth clean and dry. The prepared surface is treated with an etch and a bonding agent, and composite is placed and hardened with a curing light, in layers or in one bulk portion. Then the filling is shaped, your bite is checked and adjusted, and the surface is polished.

When is a filling not the right treatment?

Early decay that has not formed a cavity can sometimes be stopped or reversed with fluoride instead. Decay that has reached the pulp, or a nerve that has died, needs root canal treatment before the tooth is restored, and a tooth with too little structure left may need an inlay, onlay or crown. A dental examination, often with x-rays, can determine which applies.

Can old silver fillings be replaced with tooth-colored fillings?

An amalgam filling that is worn, cracked, leaking at the edges, or has decay beneath it can be replaced with a tooth-colored filling. The FDA does not recommend removing amalgam fillings that are in good condition unless that is considered medically necessary, because taking out an intact filling also removes healthy tooth structure. Where only part of a filling has failed, repairing it can preserve more of the tooth.

Can a cavity be filled at the same visit as a checkup?

Sometimes, with your permission. What happens when a checkup finds a small problem, and how often recall visits are set, is answered under dental cleanings and exams. A regular checkup is where a cavity is usually found while it is still small; as Dr. Kim puts it, "We can catch things early so we don’t lose teeth, cavities, gum disease."

Who is a good candidate for tooth-colored fillings?

Tooth-Colored Fillings is commonly recommended for individuals experiencing a cavity, where decayed tooth tissue needs to be removed and the space restored, decay around the edges of an existing filling, an older filling that is worn, cracked, fractured, or leaking around the edges, minor chips and cracks in a tooth. Schedule a consultation at ConfiDental Family and Cosmetic Dentistry in Carlstadt to find out if Tooth-Colored Fillings is right for you.

Sources & References

This article draws from 17 peer-reviewed sources.

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