What Are the Types of Dental Fillings? And What’s the Difference Between Them?

Dental fillings are an effective treatment for tooth decay. They help fill cavities caused by decay and protect the tooth. Some types of fillings also serve cosmetic purposes, especially for front teeth. The types of dental fillings vary depending on the material used. In this article, we will explore the different types of dental fillings, their advantages and disadvantages, and the differences between them.

What Is Tooth Decay?

Tooth decay is one of the most common global health issues affecting all age groups, from children to adults. It involves damage or erosion of the outer enamel layer of the teeth, resulting in cavities or holes. This erosion is caused by factors such as bacteria and excessive sugar intake.

What Are Dental Fillings?

Dental fillings are a type of restorative treatment, sometimes used for cosmetic purposes, to repair cavities, cracks, nerve damage, or minor fractures caused by tooth decay. There are several types of fillings based on the material used. Dentists can discuss treatment options and help determine the best type of dental filling for each case.

What Are the Types of Dental Fillings?

There are many types of dental fillings, each differing in material, properties, advantages, and disadvantages. The main types include:

Silver Fillings (Amalgam Fillings)

Silver fillings, also known as amalgam fillings, are among the oldest and most commonly used types in dentistry. They are composed of silver mixed with other metals like tin, copper, and mercury, and are considered safe and effective for treating decay.

Advantages:

• Durability: Lasts between 10 to 15 years or more, longer than composite fillings.
• Strength: Can withstand chewing forces.
• Affordability: Typically less expensive than composite fillings.

Disadvantages:

• Aesthetics: Silver color doesn't match natural teeth.
• Tooth structure loss: Healthy parts of the tooth may need to be removed to fit the filling.
• Tooth discoloration: Can create a grayish hue in surrounding teeth.
• Cracks and fractures: Expansion and contraction from temperature changes can lead to tooth cracks.
• Allergic reactions: About 1% of people may be allergic to mercury in amalgam.
• Mercury exposure: Amalgam releases small amounts of mercury vapor, which could be inhaled. While high exposure is harmful to the brain and kidneys, the FDA considers amalgam safe for adults and children over age 6.

Composite Fillings

Also known as composite resin fillings, these are among the most widely used types due to their natural tooth-colored appearance. They are made of a blend of resin and ceramic materials and are also known as light-cured or white fillings, as they are hardened using a blue light.

Advantages:

• Aesthetic appeal: Closely matches the color of natural teeth, ideal for front teeth or visible areas.
• Bonding: Mechanically bonds to the tooth, offering more support.
• Versatility: Can be used to repair broken or worn-down teeth.
• Tooth preservation: Often requires less removal of natural tooth structure compared to amalgam.
   

Disadvantages:

• Less durable: Tends to wear out faster than amalgam; usually lasts around 5 years.
• Longer procedure time: Takes about 20 minutes longer than amalgam fillings.
• Multiple visits: May require more than one visit to complete.
• Cracking: Depending on placement, they may cause the tooth to crack.
• Higher cost: Can cost up to twice as much as amalgam fillings.

Gold Fillings

Gold fillings are cast from gold alloy combined with other metals such as copper. Though not widely used today, they are one of the strongest and longest-lasting filling options.

Advantages:

• Durability: Can last 15 years or more.
• Strength: Highly resistant to chewing forces.
• Appearance: Some patients prefer the gold look over silver for its aesthetic value.

Disadvantages:

• High cost: Gold fillings can cost up to 10 times more than amalgam.
• Multiple visits: Usually requires at least two appointments.
• Galvanic shock: Rarely, placing a gold filling next to an amalgam one can cause a sharp pain due to electrical current produced by saliva interacting with metals.

Porcelain Fillings

Also known as ceramic fillings, these are made from porcelain or similar ceramic materials. They are more stain-resistant than composite resin and can last more than 15 years. However, they are often as expensive as gold fillings.

Glass Ionomer Fillings

Made from acrylic and a special glass material, glass ionomer fillings are often used for fillings below the gum line or in children's teeth. They release fluoride, which helps protect teeth from further decay.

Disadvantages:

• Lower strength: More prone to wear and breakage compared to composite.
• Shorter lifespan: Usually lasts about 5 years or less.
• Comparable cost: Similar in price to composite fillings.

Is It Recommended to Replace Amalgam Fillings with Safer Options?

Removing amalgam fillings unnecessarily can lead to more loss of healthy tooth structure and increased exposure to mercury vapor during removal. Therefore, it’s not advised to replace old amalgam fillings unless medically necessary, such as if decay returns under the filling or the patient has a mercury allergy.

What Is a Temporary Filling?

A temporary filling is a short-term solution used by dentists to restore or protect damaged teeth. Made from soft materials like zinc oxide eugenol, zinc phosphate, or glass ionomer, temporary fillings are not intended to last and should be replaced with permanent fillings later on.

FAQs

How long do dental fillings last?
The lifespan of a dental filling depends on the type, size, and placement, as well as oral hygiene. Some can last over 10 years with proper care.

Do amalgam fillings turn black over time?
Yes, over time the metals in amalgam may oxidize, causing them to darken and turn black.