A wire which moves teeth with less need for tightening
New from Masel.

Contents:

• CV NiTi(tm) a new wire which moves teeth with less need for tightening
• Properties Of 27°C CV NiTi
• Properties Of 35°C CV NiTi
• Properties Of 40°C CV NiTi
• Other Questions About CV NiTi
• Dangers Of Excess Dietary Copper
• Cautions For Nickel Allergic Patients

CV NiTi comes in three types:

• 27°C CVNiTi For maximum force activation
• 35 °C CVNiTi For moderate force activation
• 40 °C CVNiTi For the most gentle activation.

Each type of CV NiTi gives consistent, predictable forces which you can use to affect tooth movements.

Properties Of 27°C CV NiTi

27°C CV NiTi is a high activation force wire used to move a severely malpositioned tooth. 27°C can be readily deformed when the wire is colder than about 10°C, but the wire recovers its original shape after the wire has been in your patients mouth for about 2 weeks. Because the wire is set for below body temperature, it starts to work immediately The result is that when the wire is cold, you can bend the wire enough to reach a severely malpositioned tooth. Yet the wire will return back to its original shape, after the wire warms up to body temperature. The result is that you can easily and quickly pull a severely malpositioned tooth back into alignment. The orthodontist saves chair time since he/she does not have to do as many sequential wire changes.

To use 27°C CV NiTi, cool the wire either by storing the wire in a freezer for an hour or more, or cooling the wire with Endo-ice. Make sure that the wire stays cold as you are handling it. Bend the wire so that it can reach the malpositioned tooth. Cool the wire again to makesure that the wire does not deform while you are ligating it. Then ligate the wire in your patient's mouth as you would any other wire.

Properties Of 35°C CV NiTi

35°C CV NiTi is a moderate force activation wire used to level,align and rotate teeth. 35°C CV NiTi can be readily deformed when the wire is colder than about 20°C, but the wire recovers its original shape when the wire warms up in your patient's mouth. The wire is set at body temperature, so your patient's need to drink warm fluids to activate the wire. Again, you can bend the wire enough to ligate a rotated tooth when the wire is cool. Yet the wire will return back to its original shape,after the wire warms up to body temperature.

Rectangular 35°C CV NiTi is ideal for a "settling in" arch.

To use 35°C CV NiTi, cool the wire either by storing the wire in a refrigerator for an hour or more, or cooling the wire with Endo-ice. Make sure that the wire stays below room temperature as you are handling it. Then ligate the wire in your patient's mouth as you would any otherwire.

You will find that the wire activates slowly but you will really see the effects after it is in your patient's mouth for a month.

Properties Of 40°C CV NiTi

40°C CV NiTi is used as an initial archwire. It is designed to level and align malpositioned teeth with minimal, gentle force. 40°C CV NiTi is body heat activated and is stimulated by hot liquids. Therefore, your patients need to be told to be sure to drink hot fluids to activate the wire.

To use 40°C CV NiTi, cool the wire either by storing the wire in a freezer for an hour or more, or cooling the wire with Endo-ice. Make sure that the wire stays below body temperature as you are handling it. Ligate the wire in your patient's mouth as you would any other wire. Be sure to instruct your patients to drink hot fluids to activate the wire.

How Does CV NiTi compare to copper NiTi?

• Chemically, how isCV NiTi different than Copper NiTi?

CV NiTi and copper NiTi are very similar, chemically. Both contain mainly nickel and titanium. Both have been especially formulated and heat treated to have a superelastic phase transition at 27, 35 or 40 °C. Both have similar corrosion resistance.

The only significant chemical difference is that copper NiTi has aminor amount of copper (up to 5%) added to the nickel and titanium.

• How Are TheMechanical Properties Of CV NiTi and Copper NiTi different?

The 5% copper in the copper NiTi changes its' mechanical propertiesa little bit. However, with only 5% copper, the effects of the mechanical properties of the alloy are relatively small. The figure on the right compares the performance of 35C copper NiTi and 35 C CV NiTi at body temperature. Notice that the curves are very similar. Both CV NiTi and copper NiTi can be deformed at room temperature and below, and both recover at body temperature. The standard stress/strain curves are almost the same.

In our tests, copper NiTi recovered its shape somewhat more quickly than CV NiTi which some people might think of as an advantage. However, we think that it is an advantage for the shape to recover more slowly, since it is more comfortable for the patient that way.

• What are theclinical differences between the two wires

There have been no clinical studies which compare CV NiTi and copper NiTi. However, the mechanical properties of the two alloys are so similar that we believe that there will be very little clinical difference between the two wires.

The one big difference is that there is no copper in CV NiTi. If you have a patient who is sensitive to copper that is an important difference.

Copper - An essential nutrient but also a poison

• Patients sensitive to copper? I thought that copper was an essential nutrient!

Yes, copper is an essential nutrient, but that does not make copper safe. The USDA recommends that adults eat 2 mg of copper daily^[1]. As a result small amounts of copper are usually not at all dangerous, and could even be beneficial.

The difficulty is that according to references 1-5, copper is a heavy metal poison as well as a nutrient^[1-5]. If you digest the right amount it is good for you. However, if you digest too much, it can be very dangerous. According to the article by Baker et al^[2] worldwide, excess copper is a leading cause of liver damage in children. Scheiberg^[3]examined 135 children exposed to 8 mg/L of copper in drinking water, and found no measurable increase in liver damage. However, Baker^[2] andWalsche^[4] report deaths at similar water copper concentrations.

Copper is a particular problem for people having a rare disease called Wilson's disease. According to Propst et al^[5], "Wilson's disease is a LETHAL defect in copper metabolism causing a continual increase in tissue copper concentrations that become toxic to the liver, brain, kidney,eye, skeletal system, and several other tissues and organs" Propst et al claim that Wilson's Disease is one of the leading causes of liver failure in children in the US, and one of the main causes of childhood neurological problems.

Copper is also an allergen in some patients^[6-9]. In particular,Vilaplana et al^[9] find that copper in dental devices can cause swelling of the oral mucous membranes, and other allergic reactions in susceptible patients.

• Is this a real issue for my patients?

We do not know. We are not aware of any clinical testing to see if copper NiTi wires used in orthodontics can provoke allergic reactions, or release enough dietary copper to cause potential fatal reactions. However,the references below show that excess copper is a risk for some patients,so orthodontists should be aware of the risks.

• References to further information about copper, copper allergy and copper poisoning:
1. HH Sandstead, "Requirements and Toxicity Of Essential TraceElements Illustrated by Copper and Zinc" Am J. Clinical Nutrition,V61,621(1995)
2. Baker et al, "Copper Associated Liver Disease in Childhood" JournalOf Hepatology, V23, P538 (1995)
3. J.H. Scheiberg, et al, "Is Non-Indian Childhood Cirrhosis Caused ByExcess Dietary Copper?, Lancet, V344, 1002(1994)
4. J.M. Walsche, "Copper, Not Too Little, Not Too Much, But JustRight" J. Royal Soc Physicians - London V29, 280(1995)
5. Propst et al, "Copper-Induced Acute Rhabodomysis", Gastroenterology,V108,p885 (1995)
6. C Cavelier, Dermatosen In Beruf, V43, p202 (1995)
7. Karlberg et al, Contact Dermatitis, V9 p134 (1983)
8. Pistorr et at, J. of Investigative Dermatology, v105, p92 (1995)
9. J. Vilaplana et al "Contact dermatitis and adverse oral mucous membrane reactions related to the use of dental prostheses". ContactDermatitis, V30, p80 (1994).

Cautions

While CV NiTi is copper free, it still contains nickel. We are not aware of an fatal reactions to nickel in orthodontic cases. However, nickel is a fairly common allergen. According to a recent article in the AJOabout 30% of the orthodontic patients with pierced ears are allergic to nickel; about 3% of the patients without pierced ears are allergic to nickel. CV NiTi should not be used on patients with nickel allergy.