Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Archwire Evolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

What Makes BioForce Different? . . . . . . . . . . . . . . . . . .1

Clinical Treatment Applications . . . . . . . . . . . . . . . . . . .2

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

GAC White Paper Report

Making a Good Useof a Good Material:BioForce® Arch Wires

Dr. Mladen M. Kuftinec, StomD, DMD, ScD

Making a Good Use of a GoodMaterial: BioForce® Arch WiresIntroductionThis section will describe and illustrate appropriateuses of an outstanding orthodontic product: BioForcearch wire. A BioForce wire is a superelastic shapememory Nickel Titanium wire that provides graduallyincreasing forces from anterior to posterior segment,all within one arch wire. Therefore, BioForce wire canbe deflected or activated in such a way that it will pro-duce significantly lower forces when deflecting it in thearea that engages relatively small anterior teeth, whileit will gradually increase the force moving from theanterior to the posterior segment of the wire.

Archwire EvolutionSince the introduction of Nickel Titanium alloys forfabrication of orthodontic arch wires in 1970’s, ortho-dontic arch wires have become more complex andsuitable for a variety of intricate clinical uses, primarilydue to their great flexibility and memory retention. Infact, the race for development of the best wire createdan overabundance of what was labeled the “smartarch wires”. The differences between various products,manufactured by numerous metallurgic laboratoriesstatewide and abroad, were not significant. In certaincases the alloy was augmented by small amounts ofcopper [Cu], zinc [Zn] and noble elements [Pd, Ar]. Thechief difference, however, has been how the alloy wasprocessed or, more specifically, what stages of heatingand cooling were utilized in manufacturing of the fin-ished wires. All these wires showed an increased elas-ticity and were labeled as ‘superelastic’, lighter-forcedelivery for a given deflection and an excellent abilityto retain their initial memory. This means that no mat-ter how severely they were deflected, they wouldrepeatedly spring back into their initial passive posi-tion or configuration. One negative aspect of thesewires included their increased surface roughness,which typically increased sliding friction. For BioForcethis concern is addressed with an ionization implantingprocess utilized to alter the surface of the arch wirewithout negatively affecting the wire’s unique super-elastic properties. During the ion beam implantation

process, Nitrogen replaces Nickel on the top andchanges the surface to Titanium Nitride. BioForcewires with IonGuard® result in a significant reduction infriction during tooth movement.

What Makes BioForce Different?One of the chief characteristics of these superelasticwires is delivery of very light forces for a typical degreeof wire deflection. Practically speaking, they may deliv-er the desirable force levels for the relatively small, sin-gle rooted teeth, particularly incisors. The force maynot be adequate to either move, or to prevent anuncontrolled movement of larger teeth, particularlymolars. One can easily conclude that it would bedesirable to develop an arch wire that can producelow level of force for a given deflection [or activation]in its anterior segment, then progressively increasethat level of delivered force toward its posterior end,the part that is usually inserted into the molar tubes.

1

This is precisely why the BioForce arch wires were cre-ated. The concept was first described by Dr. Miura ofJapan. His idea was that if one starts with a “coldalloy” and then heat treats it under controlled condi-tions, the stiffness of the resulting arch wire will berelated to the length of its heat treatment. A classicalexample was offered by Miura, in which an arch wirewas not heat treated in its most posterior parts, butprogressively heat treated for longer periods of timeas it approached its anterior segment. It was experi-mentally determined that progressive time incrementsof 15 minutes worked the best for a typical BioForcearch wire.

The force delivery is affected by numerous factors: thecross-sectional dimension of the wire, the inter-bracketdistance [or the length of the lever], special orientationof adjacent teeth, among others. Let us standardizegeometry of the dental arch and assume that we use amoderately heavy arch wire, for instance a 0.016 X0.022”. While the BioForce is capable of providing theforces specified above, a typical activation of 1 mmproduces approximately 28g of force in the incisorarea, 55g in the canine-first premolar area, andapproximately 85g in the first and second molar area.

It takes less than 30g [or about 1 oz] of force to effectmost movements of incisors. Conversely, these charac-teristics can be viewed such that in the posterior seg-ment the BioForce arch wire provides close to 100g ofanchorage value against most displacements ofmolars. It is difficult to design a biologically better sys-tem of forces than this! Of course there are factorsother than the composition and characteristics of anarch wire that determine if and how teeth move, butthe arch wire is an important component of this com-plex formula.

Clinical Treatment ApplicationsLet us next look into some of the clinical situations ortreatment stages where the BioForce arch wire may bea particularly useful tool. Generally speaking, most cli-nicians tend to start the treatment by inserting a smalldiameter flexible round arch wire, e.g. 0.014”Sentalloy. With interactive self-ligating brackets, suchas In-Ovation® R, this wire will usually create verydesirable micro-movements of dentition. Misalignedteeth will start moving into better position. Thosemovements will be limited by this wire’s ability to deliv-er continuous forces adequate to affect the biologicalresponse needed to remodel the alveolar socket. Atthat point the clinician now has several choices. Hecould increase the size of the superelastic arch wire, orhe can change to a different alloy composition wire.For instance, if at this time he wants to affect theshape of the dental arch or the depth of the Curve ofSpee, the use of BioForce may be his best choice.

2

Another typical use of BioForce arch wire is in laterstages of treatment, when we are attempting a partic-ular treatment step or procedure for a prolonged peri-od of time. For instance, the posterior occlusion is notsettled in, rotations have not been fully corrected orthe bite opening is taking a long time because of theheavy musculature. These are all good reasons toplace a BioForce arch wire and allow the occlusion tosettle, while the undesirable effects of the appliedforce-producing mechanisms will be minimized.

Some practitioners like to use BioForce arch wiresearly on in treatment for cases in which significantanterior torque is needed. In these cases one can startusing a relatively large size BioForce arch wire, forinstance 0.018 X 0.025”, without the fear that its usewill cause significant root resorption.

A bit less common (and possibly viewed as unortho-dox use, but nevertheless interesting to mention) isthe application of a medium size BioForce, perhaps0.018 X 0.018” or 0.016 X 0.022” at the very start oftreatment of relatively mild cases, then leaving it inplace for several months. In a few such cases, providedthat the attachments were placed correctly, weobserved a complete resolution of the malocclusion,nearly to the point of not needing any additional archwires or additional treatment.

SummaryIn summary, it can be stated that BioForce arch wireshave the unique property of delivering remarkablyaccurate and biologically correct forces, to optimallymove the teeth of different parts of the dental arch.Together with the interactive self-ligating brackets(such as In-Ovation R or its ceramic version, In-OvationC), these wires are capable of consistently producingexcellent treatment results without causing many ofthe undesirable effects commonly encountered withthe use of other arch wire materials. BioForce is ahigh-tech product capable of achieving excellent clini-cal results.

References

Dr. Mladen M. Kuftinec, StomD, DMD, ScDDuring his career Dr. Mladen Kuftinec has distinguished himself as anorthodontist, physician and scientist. Dr. Kuftinec graduated frommedical school in the former federal republic of Yugoslavia, andreceived his Certificate of Orthodontics and DMD degrees fromHarvard University. He also holds a Doctorate of Sciences inNutritional Biochemistry degree from the Massachusetts Institute ofTechnology. Dr. Kuftinec served as the Chairman of the OrthodonticDepartment at NYU from 1990-1997, Director of the Post-GraduateOrthodontic Program until 2000, and has since been Director of NYU’sInternational Orthodontic Program. The author of more than 200 pub-lished articles and abstracts, Dr Kuftinec has made contributions toseveral books, including the recently published Excellence andEfficiency of Interactive Self-Ligation.

3

©2008GACInternational,LLC.AllRightsReserved.10.2008-120-002-02

www.gacintl.com