New dental appliances made of P.E.E.K or Acetal

New partial removable dental prosthesis made of P.E.E.K (PolyEtherEtherKetone) or Acetal, by C.F.A.O (Computer Aided Design and Manufacturing).

When there are several teeth to replace in the mouth, there are several solutions:

  • Bridges, but they are not always possible, at least one tooth must remain behind the bridge, and they often require the sacrifice of a healthy tooth. They place a sort of mortgage on the remaining teeth.
  • The Dental implants are a solution of choice, but their cost can be significant, depending on the number, complexity of the case, etc... There may be medical contraindications, bone deficits that would require reconstructions that the patient does not want, etc...
  • The third option is to make a partial removable appliance.

For more information on the 3 solutions, click here.

Until recently, these appliances consisted of a metal frame, and a resin part to hold the prosthetic teeth. The metal part is made of an alloy called Stellite™whose name has come to be equated with these braces which are commonly referred to as Stellites.

Stellite™is therefore an alloy of cobalt (50-65%), chromium (25-35%), tungsten (4-13%), carbon (1-2.5%) and other elements (molybdenum, nickel, iron, titanium).

It is important to note that cobalt is a metal that may be carcinogenic for humans, mutagenic and toxic for human reproduction (this is why in our practice we no longer use metal for crowns). Various French and European authorities have sounded the alarm. But to this day Stellite™ remains authorised in dental prostheses, although we are now obliged to inform you that this type of device contains cobalt. https://www.information-dentaire.fr/actualites/alliages-dentaires-cobalt-chrome-compatibilite-entre-le-cadre-reglementaire-europeen-et-la-convention-nationale/

Moreover, these Stellites are made using conventional techniques: (afirst physical impression to make an Individual Impression Tray, a second impression to make the frame, plaster casts, then making the frame using the lost wax technique, then putting the resin part in a muffle, etc.). All these steps are nowadays a bit archaic, long and tedious, they are also the source of inaccuracies which will add up to each other, and harm the precision of the adaptation of the whole... that's why it is often necessary to do touch-ups, and that these appliances have the reputation of generating injuries...

There is an alternative to all these problems: PEEK (polyetheretherketone, it is a thermostable semicrystalline thermoplastic) or Acetal (acetal is a synthetic polymer, obtained from formaldehyde). Dental appliances made with these materials have many advantages:  

  • These materials do not contain toxic products and have been used for a long time in orthopedics for cervical prostheses in particular;
  • they can be included in a CAD/CAM (Computer Aided Design and Manufacturing) chain, because they are machinable and printable materials. This means that we can take a optical, digital impression with our optical camera and send it to our prosthetist by internet;
  • These modern means will greatly improve the accuracy, fit and stability of your device;
  • these materials are much lighter (the frame weighs only a few grams!), your device will be more comfortable;
  • The color of this material is more natural, so the clasps will be less visible. For Acetal, several shades are even available and we can copy the shade of your teeth.

But also some disadvantages:

  • To date, devices made with these materials are not reimbursed by the CPAM, possibly by complementary organizations, but it is quite rare;
  • These high-tech materials require advanced technical means for their implementation. This results in an additional cost of about 30%;
  • these devices are more difficult to repair, they are less scalable because we can not make welds.  

It is interesting to share here the opinion of a 78 year old patient, Mrs. P. who had been wearing a stellite for many years with several inconveniences, and who decided to replace it by a PEEK appliance recently.

" I am very satisfied, the device is stable, easy to put on, very light, the food does not pass underneath anymore. No more pain. Thank you "

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