No New Equipment, Special Training or Processing

By | Dr. Gettleman's Blog

b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


 

A big reason many dental labs prefer Novus liners is that they can use conventional hot water processing with equipment they already have and know how to use, which allows them to avoid the costs of buying new equipment and retraining staff.  Processing doesn’t take much more time than with other soft liners.  Some liner products process for many hours or require boiling.  There’s even one on the market now that takes fourteen hours!

Another Novus time-and-money saver is that it helps avoid waste.  Any excess that oozes out during packing can be recovered and put in areas where there isn’t any excess, or saved for the next denture. So there’s almost no waste if you’re careful, probably less than 5%.  Most labs want to minimize the amount they throw away, especially a specialty material like Novus.

PNF Rubber – A Space-Age Material

By | Dr. Gettleman's Blog

b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


 

PNF rubber (Polyphosphazene fluoroelastomer), the main component in Novus liners, was first developed at Penn State University.  I was part of the team that obtained the final patent for it in 1987.  Dentists and lab technicians can learn its basic chemistry from that patent.

Although it’s been FDA-approved for many years, PNF hasn’t always been readily available to industry, mainly because it’s a specialty polymer that is expensive to produce and the right company hasn’t stepped up to take full advantage of its many useful properties. It’s been used for a variety of applications in the defense and aerospace industries, although not as much as it could and should have been.

Radiopacity matters!

By | Dr. Gettleman's Blog

b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


 

Everything we use in bio-medicine should be X-ray opaque in one way or another so that it can be identified it if gets into the wrong place. Say a denture shatters in an auto accident and a piece of it gets up into the nose or throat, or even a lung. That doesn’t happen very often, but when it does, it can be life-threatening. Those pieces need to be found, removed, and then you need to go back and take more radiographs to make sure they have been removed.

So that’s another great thing about Novus.  Acrylic by itself is the same density as carbon-based soft tissues and is essentially invisible to X-rays, but Novus includes barium sulfate as a filler, which imparts X-ray opacity.  Also, if a denture breaks or shatters, Novus tends to hold the pieces of the acrylic denture base together, which means small pieces of material may not break off and cause trouble.

I Love Boney Undercuts

By | Dr. Gettleman's Blog

b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


 

When I teach, I often take my students to observe surgeons extracting teeth for denture preparation. I try to stop the surgeons from removing excess bone unless it is really extreme.  With Novus in particular, the denture can engage over a bony exostosis, torus, retained tooth, implant head or some other protrusion and it locks into the undercut. The liner has to be carefully adjusted because it engages very tender tissue. That’s another advantage of Novus — almost any rotary instrument can be used to make adjustments. With silicone liners, unless you use special adjusting wheels and devices, instruments either bounce off and do nothing, or they gouge in and create feathers and other defects in liners.

Durability – It’s All in the Polymers

By | Dr. Gettleman's Blog

b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


 

We have actually seen Novus last well beyond its five-year warranty period.  That goes for conventional dentures as well as laboratory rebases and relines. I have a photograph of a denture with a Novus liner that was at least fifteen years old. It had a little discoloration, a little peeling, a little wear, but it was basically okay. The patient who brought it in didn’t want the prosthodontist to adjust it at all. “Don’t change anything!,” he said. “It’s fine!”

That durability comes from the rubber in Novus, which is about seventy percent of the liner by weight. The rubber doesn’t need plasticizers, so it stays soft and is interpenetrated with ordinary acrylics that are used in other areas of dentistry. By blending the two materials into an interpenetrating network, the best properties of both are achieved. The polymer chains of rubber are mixed with several polymer chains of acrylics, which enables them to chemically bond to the denture base, holds the material very tightly together and keeps it intact.

Prevent Bio-film, Fungus

By | Dr. Gettleman's Blog

b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


 

Every dentist knows that fungus isn’t healthy for the oral mucosal tissue that sits under a denture. It causes reddening or burning of the tissues, odors, and damage to the tissue that results in more office visits. The problem with silicones is that they are porous where the hyphae of common funguses can take hold. It can be killed on the surface, but the roots of the fungus are still down there, so it grows back up after a while. It’s like the silicone used to caulk a bath tub that has anti-fungal agents in it, but after six months, they wash out and the silicone turns black.  The fungus can be removed with bleach, but it will come back.

Novus grows much less bio-film or fungus than silicone liners. For one thing, it is non-porous.  And we think it also might be because the fluorine groups in Novus rubber keep bio-films at a minimum.

Liner Comfort Means Fewer Adjustments

By | Dr. Gettleman's Blog

b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


Comfort & Savings

We find that when dentures are delivered with Novus® liners, patients don’t come back as often for follow-up adjustments compared to other liners, and that’s a big time money-saver for dentists. That’s partly because Novus absorbs shock very well but also because it doesn’t have plasticizers, so it stays soft—it doesn’t harden and irritate a patient’s oral mucosa under the denture the way liners made with other materials often do.  The result is that patients don’t come back with sore spots, they’re comfortable. I’ve seen that myself and I hear it from a lot of other dentists as well. A dentist friend of mine who started using Novus in 1989 said to me recently: “I don’t know whether to hug you or to kiss you!” because he had so many fewer patients coming back for minor adjustments.

Novus Doesn’t Bounce

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b5658fb1-37d6-4f3a-8763-713178ffda28Dr. Lawrence Gettleman is a professor of prosthodontics and biomaterials at the University of Louisville School of Dentistry. He invented Novus and was on the team that obtained its final patent. > Click here for more about Dr. Gettleman


 

Shock absorbency is one of the most useful and valuable things about Novus.  It’s built right into the polymer structure.  We didn’t design that in but found that patients preferred the chewing feel of maxillary or mandibular dentures lined with Novus in our first clinical trials, compared to a silicone rubber liner in the denture we tested it against—they liked the natural feel when chewing.

Novus is a dead rubber rather than a live elastomer, which means it doesn’t bounce—it absorbs energy, unlike silicone rubber. It’s like a medicine ball that is dropped and it goes “thud,” compared to dropping a ball made of silicone rubber or soft, plasticized acrylic, which bounces and returns most of the energy. With Novus, most of the energy is not returned, and that turns out to be very important for patient comfort.