Updated on February 1, 2024
5 min read

Composite Fillings – Pros, Cons, Costs & Pictures

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What are Composite Fillings?

Composite fillings are dental fillings made from composite resin, a tooth-colored material. Like other kinds of fillings, they’re intended to treat cavities. The natural-looking color of composite fillings makes them popular.

teeth with dental onlay filling

Composite resin may not last as long as other kinds of fillings. But the materials have continued to improve over time, making composite resin a more durable and esthetic filling material than in the past.1

Pros and Cons of Composite Fillings

Composite resin has advantages, including:

  • Tooth-like color, which is aesthetically optimal
  • Enough durability to last several years
  • Easily bonds to the tooth, requiring less dental tissue to be removed
  • Has multiple indications, such as tooth bonding to restore chipped teeth

On the other hand, here are some of the downsides of composite fillings:

  • Less durability than metal (amalgam or gold) fillings, which can last decades
  • May take more time to place than amalgam fillings
  • More technique sensitive than amalgam fillings 
  • Higher cost than amalgam fillings
  • Possible endocrine disruptors in the composite material

Are Composite Fillings Safe and Durable?

Composite fillings are generally durable enough to withstand normal chewing and biting pressure for several years. They’re also considered safe under most circumstances.

However, there are concerns that they may release trace amounts of harmful substances, both when first placed and due to wear over time.1

Composite vs. Amalgam

Composite fillings are often compared and contrasted with amalgam (metal) fillings. Most dental fillings are either made from composite resin or amalgam.2

Several studies have shown composite fillings to be about as durable as amalgam.1 

One review found that composite fillings may be more likely to fail than amalgam fillings. However, the main cause of failure was found to be recurring tooth decay, not fracture of the fillings.4

Dental amalgam also contains mercury, which has raised concerns about it being toxic. Mercury can enter the environment when old amalgam fillings are replaced.5 Composite resin avoids these concerns, as it doesn’t contain mercury.

Since some governments around the world have agreed to phase out amalgam, composite fillings have continued to become more common.1, 2, 3

Potential Endocrine Disruptors

There have been concerns about composite fillings releasing potentially toxic chemicals into the mouth.5, 6 One such chemical is bisphenol A (BPA), which is used in many plastics and resins.1, 5

BPA is an endocrine disruptor, mimicking the effects of estrogen and other hormones in the body.7 Exposure to small amounts of it over time may cause adverse effects.8

Dental composite resin isn’t made with pure BPA, but it is often made with derivatives of BPA.8, 9, 10 Some of these have been found to have a similar hormonal effect.10, 11

UDMA, which can be leached from dental fillings over time, may also have adverse effects.12 One study of 119 different composite resins found that only one didn’t contain UDMA or a BPA derivative.8

The American Dental Association (ADA) doesn’t consider dental fillings a major source of BPA or other harmful substances.10 It also recommends ways for dentists to reduce BPA exposure, such as using rubber dams and polishing new restorations.9

How Long Do Composite Fillings Typically Last?

Composite fillings can last several years. Studies have found a median filling lifespan as low as 3 or 4 years, while others have estimated that composite fillings can last over 7 years.13, 14

This is one area where amalgam fillings tend to perform better. However, people may prefer the aesthetic benefits of composite despite its lower longevity.1

Poor diet and oral hygiene practices can contribute to new tooth decay, which also affect the lifespan of fillings.2, 3, 13 Genetic factors may also play a role.2

In addition, tobacco and alcohol use may increase the chances of failure of a composite filling.2

How Much Do Composite Fillings Cost?

Composite fillings can cost between $90 to several hundred dollars. By contrast, amalgam fillings may cost only $50 for small fillings.15

Insurance Coverage

Insurance policies vary, and some may cover the entire cost of a composite filling. However, it’s possible insurance will consider composite to be a cosmetic option.

In this case, it may only cover the cost of a composite filling up to the cost of an amalgam one. You may have to pay the difference out of pocket.15

Other Types of Filling Materials

Besides composite resin, the most common dental filling material is amalgam. Amalgam has historically been more durable, but new developments have made composite resin increasingly durable as well.1, 5

Amalgam is also being phased out, or has already been phased out, in many countries.1, 2, 5

Other alternatives to composite fillings include:

  • Gold, which is highly durable but less commonly used today. It’s also more expensive than composite resin.
  • Ceramic or porcelain, which is also durable and more expensive. Ceramic fillings are less likely to stain than composite, which makes them an attractive choice for more visible teeth.
  • Glass ionomer, which is less durable but has a toothlike color. This material also releases fluoride over time and does not require as much moisture control as composite resin.
  • Compomers, which are a hybrid of composite resin and glass ionomer cement.

Composite Filling Procedure

Here’s what you can expect during this procedure:

  1. Your dentist will administer an injection of local anesthesia. They may apply a numbing gel before the injection to minimize discomfort from the injection itself.
  2. Once you are numb, your dentist will carefully remove decayed material from your tooth using a dental drill. After that, they’ll clean and dry the area.
  3. Next, they will apply an adhesive to the exposed part of your tooth. This allows the filling to bond to the tooth.
  4. Using a syringe, your dentist will place the composite resin into the prepared area of your tooth. They’ll use a small ultraviolet light to cure the resin, allowing it to solidify.
  5. Your dentist will test your bite to make sure it’s still even with your new filling.


Composite fillings are a popular choice for many kinds of dental cavities. This is in part because they match teeth’s natural color.

While composite resin for dental fillings is less durable than traditional amalgam, it can still last several years with good oral care.

Talk to your dentist about the pros and cons of composite fillings and whether they’re the right choice for you.

Last updated on February 1, 2024
13 Sources Cited
Last updated on February 1, 2024
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. Chan, Keith H. S. et al. “Review: Resin Composite Filling.” Materials vol. 3,2 : 1228–1243.
  2. Aminoroaya, Alireza et al. “A review of dental composites: Challenges, chemistry aspects, filler influences, and future insights.” Composites Part B: Engineering vol. 216 , 108852.
  3. Vieira, Alexandre R. et al. “A Pragmatic Study Shows Failure of Dental Composite Fillings Is Genetically Determined: A Contribution to the Discussion on Dental Amalgams.” Frontiers in Medicine vol. 4 .
  4. Hurst, Dominic. “Amalgam or composite fillings — which material lasts longer?” Evidence-Based Dentistry vol. 15 : 50-51.
  5. Dental Effluent Guidelines.” Environmental Protection Agency.
  6. Gupta, Saurabh K et al. “Release and toxicity of dental resin composite.” Toxicology international vol. 19,3 : 225-34.
  7. MacKay, Harry and Alfonso Abizaid. “A plurality of molecular targets: The receptor ecosystem for bisphenol-A (BPA).” Hormones and Behavior vol. 101 , 59-67.
  8. Dursun, Elisabeth et al. “Bisphenol A Release: Survey of the Composition of Dental Composite Resins.” The open dentistry journal vol. 10 : 446-453.
  9. Bisphenol A.” American Dental Association.
  10. Bector, Aditi et al. “Xenoestrogens in Sealants and Composites.” Biomedical Journal of Scientific and Technical Research vol. 3,4 : 3430-3434.
  11. Boonen, Imke et al. “Assessing the estrogenic activity of chemicals present in resin based dental composites and in leachates of commercially available composites using the ERα-CALUX bioassay.” Dental Materials vol. 37,12 : 1834-1844.
  12. Chang, Chih-Yang et al. “Toxic Effects of Urethane Dimethacrylate on Macrophages Through Caspase Activation, Mitochondrial Dysfunction, and Reactive Oxygen Species Generation.” Polymers vol. 12,6 : 1398.
  13. Chrysanthakopoulos, Nikolaos Andreas. “Reasons for Placement and Replacement of Resin-based Composite Restorations in Greece.” Journal of dental research, dental
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