The Science Behind Quantium

Universal composites are valued for their versatility: strong enough for the posterior, esthetic enough for the anterior, visible enough on radiographs, and easy enough to work with across a range of scenarios. Meeting all of those "enoughs" at once, however, is a careful balancing act.

"We're always making trade-offs," said BISCO research scientist Natalie Keehan. "You cannot maximize every property at the same time."

Many of a composite's physical and mechanical properties work in direct opposition—improving one means giving up a bit of another. Keehan's job is to find the sweet spot between what's clinically ideal and scientifically possible.

"Our customers tell us, 'I really want a product that does ‘this,’ but also ‘this’ at the same time,'" she explained. "Then, I take that back to the lab."

Speaking with DPS about the development of Quantium, BISCO's light-cured universal composite, Keehan shared how she and her colleagues arrived at a balance of strength, polishability, low shrinkage, and radiopacity that dentists can depend on.

Pebbles vs Boulders

Much of the balancing act behind composite formulation comes down to fillers—the hard particles suspended in a composite's resin. "You can build a wall out of boulders, or you can build it out of pebbles," Keehan said.

The pebbles in this case are nanofillers: smaller particles whose greater surface area requires more resin to coat and bind them. Since resin is the weaker part of a composite, which shrinks  as it cures, more resin means more volumetric shrinkage and less strength. The upside is that nano-filled composites wear down evenly, resulting in a smooth, polishable surface.

Larger, micron-sized filler particles need less resin, so they shrink less and hold up better under bite force. "The boulders are going to give you a stronger wall," Keehan said. The trade-off is that they wear unevenly: as a restoration ages, whole particles can pop loose at once, leaving a rough, pitted surface behind.

The Best of Both Worlds

For years, clinicians had to choose between one type of "wall" or another—a strong, low-shrinkage composite for posterior teeth, or a weaker, polishable one for the anterior. Today, agglomerated fillers, the technology behind modern universal composites like Quantium, offer dentists the best of both worlds.

Agglomerated fillers are built by binding nanofillers into micron-sized clusters—like boulders made from pebbles. With less resin content, a composite like Quantium has more strength to withstand occlusal forces. But because the individual filler particles are only loosely bound, they also respond to polishing and natural wear like a nano-filled material.

"The goal is to make the biggest fillers you can to give the restoration strength," Keehan explained. "But when it wears down, you want it to break like pebbles." That leaves you with a smoother surface, which, as Keehan described it, "will help with staining and biofilm for a more esthetic appearance."

Balanced Benefits

While some manufacturers agglomerate nanofillers through extreme heat or sintering, BISCO formulated Quantium using a method called prepolymerization. Compared to sintered material, pre-polymerized filler (PPF) lets BISCO optimize different properties.

Since the resin binding the nanofillers is pre-cured and thus "pre-shrunk" before it's added to Quantium, the finished composite undergoes less volumetric shrinkage, lowering the chance of subsequent issues like secondary caries. "We can never say prevent," Keehan noted, but a product like Quantium can reduce the risk.

Emerging research points to another advantage of PPF: an apparent increase in fracture toughness. Keehan stops short of promising fewer chipped or cracked restorations with Quantium, though she expects clinicians will see fillings hold together longer.

Another puzzle for dental research scientists: the fillers that make a composite show up on a radiograph aren't the same ones that make it strong.

"The more you add to your wall, the weaker it gets," Keehan explained. With Quantium, BISCO made a strategic call to prioritize radiopacity without sacrificing strength. "We added as much radiopaque filler as we could to maintain good strength properties while having exceptional radiopacity," Keehan said. The result makes it easier for dentists to discern restorations from enamel on radiographs and spot issues like secondary caries.

As Keehan put it, "There is no one best composite—there is the right composite for a dentist and their practice." BISCO's Quantium was designed to give clinicians enough of what they want and need to deliver lasting, natural-looking restorations across a wide range of cases.