What Materials Are Used in Composite Fillings?

There are many reasons why composite fillings are popular. Most people like them because they match the color of the tooth, making it less obvious that you have had a filling. Composite dental fillings are stronger than they used to be and last longer, which are also reasons for their popularity. Knowing what composite fillings are made of may help you to decide whether this type of restoration is appropriate for your situation.

What does composite mean?

The word "composite" means "to be composed of." As it relates to fillings, it means that they are composed of more than one material.

However, there are many things made of a mixture or combination of materials that would not necessarily be considered composites. The term, therefore, implies more than just a mixture of materials. On their own, the materials used to make composite dental fillings lack chemical properties on their own that they gain when combined together. Therefore, the composite material is more than the sum of its parts, which might not occur in a mere mixture or combination.

What are the different types of materials used in composite fillings?

While composite dental fillings ingredients may vary, there are two basic types of materials.

Fillers

Fillers in a composite filling consist of tiny particles of a silicon-based material. Glass and quartz are often used as fillers in a composite filling. Fillers help to increase the fillings' resistance to wear, hardness, and tensile strength.

The final restoration is usually stronger when the filler content is higher. Smaller particles result in a smoother surface. Most composite fillings today consist of nanohybrids, which blend conventionally sized filler particles with nanoparticles, which are much smaller. If the ratio of nanoparticles to larger particles is correct, the translucency should be similar to that of natural teeth and the strength and aesthetics should be optimal. However, some nanohybrids contain too few nanoparticles in the mix.

Matrix

When talking about composite dental fillings, the word "matrix" refers to the material in which the fillers are suspended. This is typically a plastic resin known scientifically as bisphenol A glycidyl methacrylate and more commonly as Bowen's resin. The matrix starts out as a fluid and then hardens to the same consistency as natural tooth material when cured with a blue light. Confusingly, the matrix is sometimes referred to as an organic matrix even though the substance itself is synthetic to differentiate it from the inorganic filler.

Pigments are what give composite fillings their color. There is a wide range of pigments available to match the shade of the surrounding teeth. Patients should bear in mind that composite resin cannot be whitened, so the color the filling starts out is the color they will end up with in the long term.

Other additives

Composite dental fillings contain other ingredients as well. Mixing these together in different combinations results in specific outcomes according to the desires of the patient and the dentist. Other additives in composite fillings include the following:

• Stabilizers
• Coupling agents
• Polymerization initiators