The future of indirect composite restorations

January 24, 2017

A look at the ways indirect composite restorations have improved over the years, and what their future means for the dentist and for the patient.

As with most things in dentistry today, technology improves outcomes on many fronts. From 3D imaging at the clinician’s office to CAD/CAM at the dental lab, advances are all around-they are even evident in indirect composite restorations.

Thanks to sophisticated formulations, patients, doctors and labs enjoy higher-quality, easier-to-use restorations.

Better composite classes

Composite restorations can be traced back to the 1960s. When the first materials were introduced, they contained large-sized particles. Over the years, the formulations and abilities of composites have improved-and continue to evolve-offering even better outcomes for patients.

“We need better and better materials to work with,” Jim Collis, owner of Collis Prosthodontic Lab in Mount Prospect, Illinois, says. “Technology is definitely helping us achieve the goal of making better materials.”

In recent years, manufacturers have addressed those concerns, bringing new classes of composites to the marketplace.

“One of the most significant advances has been the development of new classes of composite materials for use in chairside CAD/CAM systems which contain predominately inorganic refractory compounds, such as glass and ceramic fillers,” Geoffrey P. Morris, PE, Scientific Affairs Manager at 3M Oral Care says. “These materials, such as 3M’s Lava Ultimate CAD/CAM Restorative, contain 80 percent by weight inorganic fillers and have demonstrated clinical performance as an adhesively bonded onlay, at three-year recall, equivalent to leucite-reinforced glass-ceramics.”

Esthetics

Patients want their restorations to be just as good as real teeth-from the standpoints of both form and function.

“Patients have high esthetic expectations,” Collis says. “They want to appear as natural as possible. Some of these materials that are coming out now can help us achieve the goals of the patient when they go the doctor.”

The technology behind composites improves over older, traditional materials.

“The incisal translucency is incredibly important,” Collis says. “You can achieve that with ceramics, for sure, but the problem with ceramics is if something cracks in the mouth it is really hard to repair, chairside.

“I’ve been using Shofu’s Ceramage for quite a while now,” he continues. “It is a zirconia-silicate microceramic that exhibits virtually the same light transmissions as a natural tooth. It maintains a remarkable translucency. In this day and age everybody wants Hollywood teeth and wants to look completely natural and beautiful, and I think the materials need to be able to achieve that.”

Up next: More of the enhanced features in modern technologies

Wearability

Esthetics are the first thing that the patient sees when he or she looks in the mirror, but function matters just as much as form. The size of the particle is what makes the composites better with each new formulation.

“Lava Ultimate utilizes mixtures of different filler particles,” says Morris. “Some are nano in size (smaller than the wavelength of light) which help reinforce the continuous resin phase. Others are designed to provide for abrasion resistance and radiopacity of the composite. By engineering the types of fillers employed, the resulting material is predominately inorganic, or ceramic, in composition.”

The types of materials used in composites also have an impact of their wearability.

“Composites, like Ceramage, have 73 percent zirconia, and that’s going to give you great wearability in the mouth,” Collis says. “When you compare it to a standard composite, the wearability is still great-it’s still better than PMMA-but the glass or the zirconia in Ceramage far surpasses any of the wearability of standard composites.”

Handling

The patient, naturally, has to be happy with their restorations, but everyone responsible for the restoration’s creation and placement must also be able to use them easily.

“As technicians, we have to use products that will please the patient,” Collis says. “That’s the number one goal: to please the patient. You have a doctor that is going to insert it, and then, even before that, you have a technician who has to use the product. In the manufacturing stage, if we can use technology to manufacture products that we can use easily, that the doctor can put into the mouth easily, and the patient is going to look in the mirror and say, ‘Hey, wow this looks really great,’ that’s the goal. That’s the whole goal. If we can use technology to get us to that point, then that’s fantastic, that’s great.”

Safety is another factor in composites’ ease of use.

“The only thing we had in the past to stain dentures was cold-cured acrylic and heat-cured acrylic,” Collis says. “You had mix the stain with monomer, place them in the flask, wet them with the monomer and paint it on top of the denture afterward. Monomer is like a swear word. It’s not healthy stuff. If you can smell it, that means it’s in your body, and that’s not a good thing. The composites are kind of inert. That takes it to a whole other level. We have a lot more control. We can paint it on the surface and see exactly what it’s going to look like. The color that you painted on is the color that it is going to be when it’s cured. We have so much more control now with light-cured composites.”

Economics

Productivity matters, and the ability to produce quality, easy-to-handle, esthetic restorations is a factor made possible by improved technology.

“Because of the viscosity of these composites, you can actually build up tooth shapes right out of the gun, or you can use a probe or a brush” Collis says. “And that makes things a lot easier.”

Compared to older methods, composites are much less time-consuming and are easier to produce.

“In a good technician’s hands, they can produce a restoration in a very timely fashion,” Collis says. “Composites are more economical to manufacture than porcelain. [With composites] you have a couple of different bakes, and that is very time-consuming-you have a three-minute cure as opposed to heating up a restoration, letting it cool and then going back to apply the body porcelain. With composites, you put the opaque on, you have a three-minute cure and right away you can put your body coloring on, you give it a 10-second cure in-between each layer, and then a final cure of three minutes. So you’re talking about a time savings, too.”

Thanks to the science and technology behind indirect composite restorations, the end product is a benefit for lab, doctor and patient.