What Materials Are Used in Composite Fillings?

There are many reasons why composite fillings are popular. Most people like them because they match the tooth's color, making it less obvious that you have had a filling. Composite dental fillings are also known to be strong and last for years. Knowing what composite fillings contain may help you to decide whether this type of restoration is appropriate for your child’s needs.

What does composite mean?

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

Many things would not necessarily be considered composites. The term implies more than just a mixture of materials. For example, the materials used to make composite dental fillings lack chemical properties that gain when combined. 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 filling 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 common options for 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 much smaller nanoparticles. If the ratio of nanoparticles to larger particles is correct, the transparency 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

The term "matrix" refers to the material that holds the fillers in place. This is typically a plastic resin known scientifically as bisphenol A-glycidyl methacrylate and, more commonly, Bowen's resin. The matrix starts as fluid and then hardens to the same consistency as natural tooth material when cured with a blue light. The matrix is sometimes referred to as an organic matrix, even though the substance is synthetic, to differentiate it from the inorganic filler.

Pigments

Pigments are what give composite fillings their color. There is a wide range of pigments available to match the shade of the child’s surrounding teeth. Parents should remember that composite resin cannot be whitened, so the color the filling starts with is the color their child will have in the long term.

Other additives

Composite dental fillings contain other ingredients as well. Mixing these together in different combinations results in specific outcomes. These combinations are determined by the pediatric dentist, their patient, and their patient’s parent. Other additives in composite fillings include the following:

• Stabilizers
• Coupling agents
• Polymerization initiators