Filling All the Gaps: Flowable Composites

Flowable composites are versatile materials—they’re suitable for use in temporary crown repair, veneer cementation, porcelain repair, pit and fissure sealing, and they’re also used as liners and bases. More commonly, flowables are used in Class III, Class IV, and Class V restorations. These materials offer excellent handling properties.

With a lower viscosity than their composite counterparts, flowables are able to work their way into the cracks and crevices of a preparation that may be more difficult to fill with a thicker material. The lower viscosity also allows for thin layers to be placed, preventing bubbles or voids in the material.

Of course, what makes flowable composites suitable for some restorations limits their effectiveness in others. When the material was first introduced in the 1990s, it was more viscous due to its formulation. At first, manufacturers reduced the material’s filler content to about 50 to 60%. This decreased their strength and wear properties. Less filler content can also reduce the material’s mechanical properties. The early generations of flowables were also plagued by increased polymerization shrinkage.

However, newer materials typically have a higher filler content than their predecessors. Flowable composites manufactured in 2010 and later typically have a filler content that ranges from 70 to 80%. This increases the material’s wear resistance and strength, something that has steadily improved since the materials’ introduction.

A 2015 study found that flowable composites had similar clinical outcomes in Class I restorations after a 2-year recall when compared to highly filled traditional composites.

A 2018 study reached a similar conclusion—that flowables have a comparable clinical efficacy in “small- to moderate-sized occlusal restorations.”

Here, we feature 16 of the industry’s flowable composite offerings.