In the past, teeth were filled with a mixture — or amalgam — of different metals (silver, tin, copper, and mercury). Today, that is changing as more natural-looking and metal-free fillings are becoming the preferred approach. Dentists are using more tooth-like materials (composite resins and porcelains) that are both safe and predictable. The most important feature, for many people, is that they look and react more like natural teeth.

Tooth anatomy and how fillings mimic it:

• Enamel: The external part of the tooth; the hardest natural material produced by animals. It consists of very closely knit calcium crystals and contains no living tissue. Dental porcelains easily and efficiently imitate enamel.

• Dentin: The inner part of the tooth; more porous and similar to bone. It consists of microscopic tubes of collagen with calcium crystal deposits. Dentin is living and very sensitive. Composite resins mimic dentin.

Types of cosmetic fillings:

1. Composite resin fillings: Made of a plastic resin and silica filler. They bond directly to tooth structure, requiring less removal of healthy enamel. They match tooth color and are ideal for front teeth or visible areas.

2. Porcelain (ceramic) fillings (inlays/onlays): Fabricated in a lab, highly stain-resistant, and very durable. Usually require two visits.

3. Glass ionomer fillings: Release fluoride, often used for children or root surfaces, but less durable.

Advantages over amalgam:

• No mercury content

• Bond to tooth, strengthening it (amalgam requires undercuts, weakening the tooth)

• Less tooth removal needed

• No metal expansion or corrosion

• Natural translucency and color

Longevity and statistics:

• A 2019 meta-analysis in Dental Materials found that composite fillings have a 90% survival rate after 5 years and approximately 80% after 10 years.

• The average lifespan of a composite filling in a low-stress area (front teeth) is 7–10 years; in molars, 5–7 years.

• Amalgam fillings last 10–15 years but require more tooth removal and are cosmetically poor.

Procedure (direct composite filling):

1. Anesthesia (if needed)

2. Removal of decay

3. Etching and bonding agent application

4. Layering of composite resin

5. Shaping and curing with a special light

6. Polishing

References:

• Ferracane, J.L. “Resin composite—state of the art.” Dent Mater, 2011.

• Heintze, S.D., Rousson, V. “Clinical effectiveness of direct composite restorations.” Dent Mater, 2019.

• Hickel, R., et al. “Longevity of composite restorations.” J Adhes Dent, 2013.