What is the Difference Between Amalgam and Composite

In the world of dentistry, the choice between amalgam vs composite fillings has long been a topic of discussion. Both materials have their unique advantages and disadvantages, and their use often depends on the specific needs of the patient and the dentist’s recommendation. This article offers an in-depth look into these two popular filling materials, guiding you through their key differences, similarities, benefits, and potential drawbacks.

What is the Main Difference Between Amalgam and Composite?

The main difference between amalgam and composite is that amalgam is a silver-colored filling made from a combination of metals including mercury, silver, tin, and copper, while composite is a tooth-colored filling material made of resin-based compounds and finely ground glass-like particles. Amalgam has been used for over a century and is known for its durability, especially in molars. In contrast, composite provides a more aesthetic solution that blends seamlessly with the natural tooth and bonds directly to the tooth structure, often preserving more of the natural tooth compared to amalgam.

What is Amalgam and What is Composite?

Amalgam is a dental filling material traditionally made from a mixture of metals, including mercury, silver, tin, and copper. Due to the presence of mercury, amalgam fillings have a silvery appearance. They have been used for over a century in dental practices and have a reputation for strength and durability.

On the other hand, composite is a tooth-colored filling material primarily made of resin, a plastic material. It’s known for its aesthetic properties, allowing for a more natural appearance when filling a cavity or repairing a chipped tooth. Composite fillings bond directly to the tooth, which can provide further support.

Key Differences Between Amalgam and Composite

Composition: Amalgam is primarily a mixture of metals, while composite is a resin-based material.
Appearance: Amalgam fillings are metallic and silvery, whereas composite fillings are tooth-colored.
Bonding: Composite materials bond directly to the tooth, while amalgam does not.
Durability: Amalgam is generally considered more durable and can last longer than composite, especially in areas with heavy chewing loads.
Placement Technique: The cavity preparation for amalgam fillings might be more extensive because the filling doesn’t bond directly to the tooth. In contrast, composite fillings require less removal of tooth structure.
Cost: Typically, amalgam fillings are less expensive than composite fillings.
Sensitivity: Patients might experience less post-treatment sensitivity with composite than with amalgam.
Health Concerns: There have been concerns and debates about the mercury content in amalgam, although numerous scientific studies have deemed them safe for use. Composite doesn’t contain mercury.

Key Similarities Between Amalgam and Composite

Purpose: Both are primarily used for filling dental cavities.
Protection Against Tooth Decay: Both materials help seal off areas of decay to prevent further deterioration of the tooth.
Functionality: After curing or setting, both materials can handle the forces of chewing and biting.
Longevity: With proper care, both amalgam and composite fillings can last for several years, though the exact duration can vary.
Biocompatibility: While the compositions differ, both are generally considered safe for use in patients, barring individual allergies or sensitivities.
Modification: If needed, both types of fillings can be adjusted by the dentist after placement, whether for comfort or fit.

Pros of Amalgam Over Composite

Durability: Amalgam fillings are known for their strength, especially in molars and areas that experience significant chewing forces.
Longevity: Typically, amalgam fillings can last longer than composite ones, sometimes even 10-15 years or more with proper care.
Cost-Effective: Amalgam fillings are usually less expensive than their composite counterparts, making them an economical choice for many patients.
Less Technique-Sensitive: The procedure for placing an amalgam filling is less sensitive to moisture and other factors, which can be an advantage in certain situations.
Proven Track Record: Amalgam has been used in dentistry for over a century, and its long-term effects and performance are well-documented.
Low Maintenance: Amalgam fillings generally require less maintenance and are less likely to need early replacement or repair than composite fillings.

Cons of Amalgam Compared to Composite

Aesthetics: Amalgam fillings have a metallic appearance that can be less aesthetically pleasing than the tooth-colored composite fillings.
Tooth Preparation: Because amalgam doesn’t bond directly to the tooth, more tooth structure might need to be removed to place an amalgam filling compared to a composite one.
Sensitivity: Some patients might experience thermal sensitivity with amalgam fillings, especially in the initial days after placement.
Mercury Content: While considered safe by many health organizations, the mercury in amalgam has raised concerns among some patients and professionals.
Less Conservative: Amalgam fillings don’t bond to teeth, often necessitating more extensive cavity preparations.
Potential for Cracks: Over time, amalgam can expand and contract with temperature changes, which might lead to cracks in the tooth.
Biocompatibility Concerns: Some patients might have allergies or sensitivities to metals used in amalgam.

Pros of Composite Over Amalgam

Aesthetics: Composite fillings are tooth-colored and can be closely matched to the shade of the surrounding teeth, making them virtually invisible.
Preservation of Tooth Structure: Because composite bonds to the tooth, less tooth structure may need to be removed compared to when placing amalgam fillings.
Bonding Capability: Composites bond directly to the tooth structure, providing additional support and seal.
Minimal Sensitivity: Composite fillings often result in less post-treatment sensitivity compared to amalgam.
Metal-Free: For those concerned about metals or potential allergic reactions, composite provides a metal-free option.
Immediate Functionality: After a composite filling is placed, it’s fully set, allowing patients to eat immediately.

Cons of Composite Compared to Amalgam

Durability in Large Fillings: For particularly large fillings or those in molars, composite might not be as durable as amalgam.
Longevity: Composite fillings might not last as long as amalgam fillings, often requiring replacement or repair sooner.
Cost: Generally, composite fillings are more expensive than amalgam fillings.
Placement Time: The procedure for placing a composite filling can be longer than for an amalgam filling, especially if there’s significant decay.
Staining Potential: Over time, composite fillings might become stained from certain foods, drinks, or tobacco.
Technique Sensitivity: The procedure to place a composite filling is more technique-sensitive, requiring a dry field and more precise placement to ensure success.
Material Wear: Composite might wear down faster than amalgam, especially in areas of heavy chewing.

Situations When Amalgam is Better Than Composite

Large Cavities in Molars: Due to its superior strength and durability, amalgam can be a better choice for large cavities in the back teeth, where the chewing forces are significant.
Below the Gumline Fillings: Amalgam may be more suitable for cavities located below the gumline because it is less sensitive to moisture during placement than composite.
Patients with Bruxism: For patients who clench or grind their teeth, the durability of amalgam can be beneficial.
Cost Concerns: When budget is a primary concern, amalgam fillings are typically less expensive than composite.
Deep Cavities: In cases where the cavity is deep and close to the pulp, amalgam’s thermal conductivity can be advantageous.
Lengthy Dental Procedures: For patients who have difficulty keeping their mouths open for extended periods, the quicker placement of amalgam might be preferable.

Situations When Composite is Better Than Amalgam

Front Teeth Fillings: For cavities in the front teeth or any visible area, the tooth-colored appearance of composite is a clear advantage.
Minimal Tooth Removal: If the goal is to preserve as much natural tooth structure as possible, composite’s adhesive properties can be advantageous.
Small to Mid-sized Cavities: For smaller cavities, the aesthetic and bonding benefits of composite make it a preferable choice.
Teeth with Fragile Structures: Composite can bond and support the remaining tooth structure, helping to prevent breaks or fractures.
Allergic Reactions: For patients allergic to metals used in amalgam, composite offers a metal-free alternative.
Aesthetic Concerns: Patients who prioritize aesthetics might prefer composite due to its ability to blend seamlessly with the natural tooth.
Immediate Cosmetic Corrections: Composite can also be used for dental bonding procedures to fix minor chips or gaps between teeth.

FAQs

How long does it take for amalgam and composite fillings to set?

Amalgam fillings can take up to 24 hours to fully set, although it’s generally safe to eat after a few hours. Composite fillings, on the other hand, are cured using a special light during the procedure, so they set immediately.

Are there any health concerns related to the mercury in amalgam fillings?

The American Dental Association (ADA) and other health organizations have stated that the mercury in amalgam, when combined with other metals, is safe for use in fillings. The amount of mercury released in the mouth under the pressure of chewing and grinding is extremely low and falls well below general safety standards. However, if patients have concerns, they should discuss alternatives with their dentist.

Can existing amalgam fillings be replaced with composite ones?

Yes, amalgam fillings can be replaced with composite ones if they are worn out, broken, or if a patient prefers a tooth-colored alternative for aesthetic reasons. It’s essential to consult with a dentist before making this decision.

How should one care for teeth after getting a filling, irrespective of the material used?

After receiving a filling, it’s recommended to avoid eating or drinking for a few hours to allow the filling to set (especially for amalgam). Regular oral hygiene practices like brushing, flossing, and regular dental check-ups are vital. It’s also advisable to avoid very hard, sticky, or chewy foods that might dislodge a new filling.

Do composite fillings stain over time?

While composite fillings are designed to match the color of natural teeth, they can stain over time, especially if frequently exposed to coffee, tea, red wine, or tobacco products. Regular dental cleanings can help minimize staining.

What factors determine the cost difference between amalgam and composite fillings?

The cost can vary based on factors like the dentist’s expertise, geographic location, the complexity of the filling, and the material costs. Typically, composite fillings might be more expensive due to the material cost and the longer time needed for placement.

Conclusion

After a comprehensive exploration of amalgam vs composite, it’s evident that both materials have a significant place in modern dentistry. The choice between them should be based on individual patient needs, the specific dental situation, and aesthetic preferences. As dental technology and materials continue to evolve, it’s crucial to stay informed about the latest developments to make the best decisions for one’s oral health.

Points of Comparison	Amalgam	Composite
Composition	Mixture of metals, including mercury, silver, tin, and copper.	Resin-based, tooth-colored material.
Appearance	Metallic and silvery.	Matches the natural tooth color.
Durability	Often more durable, especially in areas of high chewing forces.	Might wear down faster, especially in areas of heavy chewing.
Bonding	Doesn’t bond directly to the tooth.	Bonds directly to the tooth.
Cost	Generally less expensive.	Typically more expensive.
Longevity	Can last longer (10-15 years or more with proper care).	Might need replacement or repair sooner than amalgam.
Aesthetics	Not ideal for visible teeth due to metallic appearance.	Preferred for visible teeth due to natural appearance.
Pros	Durability, cost-effectiveness, less technique-sensitive.	Aesthetics, preservation of tooth structure, bonding capability.
Cons	Potential mercury concerns, more tooth removal, aesthetic concerns.	Not as durable in large fillings, can stain over time, more expensive.
Ideal Situations	Large cavities in molars, below the gumline fillings, patients with bruxism.	Front teeth fillings, small to mid-sized cavities, aesthetic corrections.