The technique uses light, biological forces via bio-efficient super elastic archwires and a unique new bracket design to shorten treatment time, reduce patient discomfort and reduce the potential risk of root resorption.
The Viazis bio-efficient appliance system is fast, with average treatment times taking about one year.The triangular bracket was designed to provide the first differential stiffness bracket to accommodate the new, differential - force superelastic .
It is a twin bracket with single slot. The slot is elevated so that during the archwire insertion the interbracket span of wire is more, which allows for easier wire insertion
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Bio-efficient Archwires:
According to Dr Thomas Creekmore (1982) less force is required with greater tooth movements. The recent introduction of super elastic archwires has allowed the clinician to achieve this objective.
The super elastic archwires allow doctors to use square initial wires for total tooth movement (crown and root). Regardless of the extent of activation these new archwires provide a light constant force. The wires are very different from the first generation, work hardened NiTi wires in that they possess shape memory and super elastic properties.
Because of the wide range of activation of these new super elastic wires, a doctor only needs to see his patients, for orthodontic adjustments, every eight to twelve weeks. As a result the doctors’ time is greatly reduced and the number of patients he can see is increased.
The non-linear unloading of the super-elastic archwires has an initial rapid drop in the force level applied to the teeth. This means that less forces are applied upon greater activation. Super elastic square wires are preferable over round wires as they allow for initial full bracket engagement and, in turn, simultaneous correction of rotations, angulations, alignment, and torque.
Before inserting these wires in the mouth the clinician must use local ice application (Polar Bear sticks) and preserve the wires in the refrigerator. This decreased temperature allows the wires to be in their plastic phase (martensitic); there they can be easily placed into the bracket slots. At oral temperatures (austensinic), the wires resume their original arch form shape (shape memory). The combination of shape memory and super elasticity makes these new wires very comfortable for the patient, (even in a square form) when used as initial archwires.
Because the super-elastic wires are temperature sensitive the clinician can advise their patients to rinse with ice water to reduce discomfort during the initial weeks of straight wire therapy. The cold drink returns the wires to their plastic phase and thus reduce force levels as the wires momentarily self adjust in the bracket slot.
These new super elastic square wires allow for initial full bracket engagement for the correction of rotations, alignment, levelling, and space closure. In a modern practice a doctor can approach the first three stages of orthodontic therapy (alignment, levelling, and space closure) as part one of the treatment. This allows the doctor to spend an equal amount of time in finishing a case as they did aligning the teeth. Spending extra time in case finishing encourages a superior result and greater stability. For the majority of patients a two-wire system is used. The initial arch wire is a super elastic nickel titanium wire and the finishing wire is stainless steel. The objective is to start alignment, levelling and space closure with the super elastic wires and finish with stainless steel. Every attempt should be made to place the stainless steel archwire as soon as possible to enhance levelling and maintain archform.
The disadvantage of super elastic wires is that they cannot be conformed in the transverse dimension. Excessive use of nickel titanium archwire causes an excessive expansion of the intercanine width. This has been shown to be unstable in the long term. The other benefit of stainless steel wire is that it has much lower frictional properties than nickel titanium and can be individualised to produce an ideal arch form for each particular patient. For this reason I recommend that finishing stainless steel wires are placed as soon as possible and conformed to the patients ideal archform.
I recommend the use of square super elastic wires as the initial alignment archwires because stiffness is directly proportional to the width and inversely proportional to the tube of thickness. A square wire reduces the thickness and decreases the stiffness. This is why square wires are more effective for levelling and rotating teeth.
THE TRIANGULAR BIO-EFFICIENT BRACKET:
The Viazis bracket was one of the few orthodontic brackets that were designed after the introduction of the new super elastic archwires. Dr Viazis quite cleverly designed his bracket to maximise the effect of the super elastic archwires from the onset of therapy. This is accomplished by incorporating a number of unique features within the pre-adjusted bracket. As stiffness is inversely proportional to the tube of the length of the wire and the amount of deflection or range is proportional to the square of the length of the wire, then an archwire between “narrow slot” brackets would have 3.37 times less stiffness and 2.25 times greater activation, and thus overall much greater flexibility. It is obvious, then, that single slot brackets (narrow) should be more efficient. Why is it then that such brackets have not been as popular as the twin systems available? The answer to this question is that the narrow width (single type) brackets have virtually no rotational capability or tipping control. The Viazis bracket, however, has these capabilities and numerous other design features:
1. The inter-slot distance is increased to ensure maximum arch wire flexibility.
2. Friction between the brackets and the arch wire is dramatically reduced by using a single slot type contact with the slot elevated off of the horizontal member
3. Elbow side extensions are employed to prevent loss of tip control. As tooth movement begins the arch wire contacts the elbows and the narrow single slot momentarily becomes a wide twin slot. This, in turn, results in root movement before any further crown movement can occur. The net effect is a “walking” of the tooth into the desired relationship in a “zig zag” manner.
4. Maximum rotational control is obtained by using an elongated thin configuration. This allows the twin wings to be extended to the mesial and distal surfaces of the tooth.
5. The brackets are pre-torqued. By using a .020 x .020 starting arch wire, torque is obtained in the early phase of treatment.
The above features produce an interactive variable ligation triangular design. Low friction bracket technology is very efficient when coupled with the new, high tech, low force arch wires. Further training in the Viazis technique is recommended, however, before using this bracket system. In such a seminar the various ligations can be demonstrated. These ligations allow unsurpassed control of individual tooth movement.
The Viazis bracket enhances “orthodontic economics” as it offers a clinician the speed of the smallest single slot bracket available with the control and stability of the largest twin slot bracket on the market. The bracket is easy to place due to its triangular design and has outstanding retention due to its unique contoured base.
Conclusion:
By using the new Viazis 0.022 slot bracket, in conjunction with the .020 x .020 square super elastic arch wires, treatment time can be greatly reduced. This can be accomplished without compromising patient comfort or treatment quality. The clinician can easily incorporate this new appliance system into his or her orthodontic practice. This means that a doctor can start a larger number of cases as total treatment time is greatly reduced with fewer visits required and patients seen at greater intervals.
