Indirect Band TechnicJOHN T. LINDQUIST, D.D.S.Indianapolis, IndianaUntil the discovery of Magic-X,orthodontists will have to continue theirband making efforts. Magic-X is thatperfect adhesive which will enablebrackets and tubes to be cementeddirectly to the teeth. Perhaps thisrevolutionary material will be discover-ed soon - perhaps never. In the mean-time, any improvements in band mak-ing procedures should be welcomed bythe profession. This paper will presentan original indirect band technic whichhas proven itself in several years ofclinical practice. It overcomes manyof the objections to previous methodsand, in addition, it is actually an in-direct appliance construction methodrather than a band technic alone. Ithas been designed for indirect con-struction of a complete edgewise archapp!iance ; hewelver, any mc!tip!e hand-ing appliance can be adapted to thistechnic.It has not seemed feasible to mostorthodontists to make bands by an in-direct method. The quality and fit arebelieved to be lacking. This may havebeen the case with some previousmethods, but it is no longer true. Ortho-dontics is in about the same stage nowthat crown and bridge work was aboutten years ago. Until the advent of agood hydrocolloid technique mostdentists had the same doubts about in-direct inlay work that we orthodontistshave about indirect appliance construc-tion. Prior to hydrocolloid few menwould cast an inlay without trying thewax pattern in the mouth - even if aso-called indirect method was used. To-Read before the Edward H. Angle Societyof Orthodontia, Waahington, D.C., 1957.day the completely indirect hydrocolloidmethod is very successful and has gain-ed widespread acceptance. This com-parison is being drawn merely to pro-mote unbiased thinking.Band construction by any directmethod, including the use of preform-ed bands and contoured band strips,has always been a time consuming andfatiguing procedure. The mental strainand fatigue of the orthodontist can onlybe matched by the discomfort of the pa-tient. Most of this discomfort can beeliminated by the procedures to be ex-plained. With the technic to be pre-sented, it is also possible to eliminatethe work and discomfort involved intaking individual imprcssions of eachtooth to be banded. Most indirect bandtechnics require individual tooth im-bands or aluminum shells. A single up-per and lower impression is all that isnow required. From these impressionsextremely hard metallic type dies aremade of each tooth. After bands havebeen constructed from these dies allbrackets and tubes can be accuratelypositioned. Initial archwires and a facebow headgear can also be constructed-all from a single impression of eacharch. Competent technicians can betrained to do this work, leaving valu-able time for the orthodontist to bettercare for his patients. Added to theseobvious advantages is the possibilityof constructing a superior appliance, forband adaptation and bracket and tubeplacement can be definitely better thanwith direct methods.Appliance construction by this in-direct method is a three stage pro-cedure. Separation, impressions, checkpre ns, usga!!y :yith rnnnpr --rr--1 I4 Vol. 29, No. 2 Indirect Technic 1 I5fitting and cementation are all that isrequired. A complete appliance can beseated at one appointment after theteeth have been separated and impres-sions taken. Chair time can be reducedby more than one-half.The development of this technic wasmade possible by the introduction oftwo new materials. The first of theseis rubber base impression material. Withit an im6ression can be taken that willextend under the gingival tissues slight-ly and increase the length of the clinicalcrown on the model. This material alsomakes possible the use of some superiordie materials. The second new materialis a die material that is very accurateand possesses extreme surface hardnessand strength. Plastic steel was adaptedby the author for use in dentistry withthe rubber base impression materials.It is composed of 80% finely powderedsteel particles and 20% plastic. Thesurface hardness is much better clinical-ly than copper plate or low fusing metaldies. Hydro-cal or stone dies exhibitexcessive surface wear and are general-ly unsatisfactory for band construc-tion.With an impression material that iscapable of reproducing the tooth sur-face slightly under the gingival marginand a superior die material the follow-ing technic was evolved over the lastthree years. In its final form, the diepositioning portion was patterned af-ter a techsic that is used in crown andbridge work. The dies can be re-as-sembled to the exact form of the orig-inal malocclusion model. Accuracy is sopositive that fixed bridges can be con-structed by this method.A detailed step by step procedurewill now be given. This will be follow-ed by a discussion of the advantages anddisadvantages of adapting this methodto a busy orthodontic practice. Finally,the advantages of chrome steel andchrome nickel alloys will be stated inreference to use with the indirect ap-pliance construction technic. SEPARATIONAdequate separation is an absolutenecessity for successful use of this tech-nic. This is essential, however, for goodband construction by either direct orindirect methods. Separation must beobtained between each tooth in themouth. This should be of such degreethat all bands can be cemented at onetime without binding, or forcing theteeth apart during cementation. Theamount will depend upon the thicknessof band material used and the close-ness of band adaptation. When thisamount of separation is obtained, theimpression material will flow betweenthe contact areas and accurately re-produce the mesial and distal surfacesof the teeth involved. A septum of thistough rubber material will separate allteeth in the impression after it is re-moved from the patient's mouth. Theimportance of this will also be realizedwhen the dies are reassembled to theform of the original model.Separation of this degree can be ob-taified with a minimum of discomfortby using some of the so called "physio-logic" methods. Kesling separatingsprings are excellent for use on pos-terior teeth. Brass wire can also beused on cases where separation is notdifficult to obtain. If teeth are to beextracted, this should be done approx-imately one week before separation isplaced. Springs or wires should beplaced three or four days before im-pressions are to be taken. In extremelydifficult cases these should be replacedor tightened and allowed to act longer.Anterior teeth can be separated withMaxian elastic separators which areusually placed one day before impres-sions are taken. Many patients can beinstructed to place these at home, there-by eliminating an extra visit to the 116LindquistApril, 1959orthodontist. If left longer than one ortwo days, these elastic separators canbe irritating to the gingival tissues. Onless difficult cases brass wire can beplaced on the anterior teeth at the sameappointment when the springs are seat-ed. By using the "physiologic" methods,i.e., springs and elastic separators, muchof the discomfort of separation can beeliminated and extra appointmentsavoided.IMPRESSION TECHNICAll separating springs, wires, orelastics are removed and the teeththoroughly cleaned. A rubber cup of theB.S. type is used with pumice to cleanthe tooth crowns. This style cup willflare out and extend below the gin-gival margin. It is very important thatthis area be clean. Scalers should beused if calculus is present. The distalsurfaces of the lower second molarsshould be packed with a string or wispof cotton saturated with a 20% solu-tion of zinc chloride if tissue coversthese areas and it is desired to bandthem. This is placed at the beginningof the appointment. By the time therubber base impression is ready to betaken the tissue will be retracted, there-by eliminating a waiting period for thisaction. It is usually unnecessary to packany other areas since the impressionmaterial will flow slightly under thegingival margins if these areas areproperly cleaned.A compound impression of each archis taken. This acts as a tray for therubber base material. The compoundimpressions are jiggled when first seat-ed to enlarge the space for the teeth;by moving or jiggling the impressions,enough room for the secondary im-pression can be created. This elimi-nates the need for trimming or remov-ing material after the compound istaken from the mouth. Additionalspace can be created if needed by work-ing the end of a mirror handle in thesoft compound immediately upon re-moval from the mouth. One of thefundamental principles of using rub-ber base impressions is to have a closeadapting tray which minimizes thethickness of the impression material.The compound impression tray alsoprovides a peripheral seal all aroundthe impression which may help to forcethe impression material below' the gin-gival margins. For these reasons the useof the compound tray is recommended.To insure proper working consistencyof the compound it is necessary to havewater temperature at the manufac-turer's recommendation or slightlyhigher. An automatic saucepan, asshown in Figure 1, is ideal for this pur-pose. It can be calibrated to the powertemperature by using a thermometerand marking the dial. When once cali-brated, it will thermostatically keep thewater within a three degree variation.The compound can be heated beforethe patient arrives and will stay at theproper working consistency for as longas desired. Figure 1 also shows theloaded tray. An average size tray willrequire lvz cakes of compound. Uponremoval from the mouth the impressionFig. 1 Vol. 29, No. 2 Indirect Technic I I7is dried with air. The use of an ad-hesive is recommended. A thin coat ofadhesive will prevent the rubber basematerial from pulling away from thecompound. This is necessary with somerubber base materials. If no difficultyof this type is encountered, the ad-hesive is unnecessary.A heavy-bodied type rubber basematerial such as Kerr's Heavy BodiedPermlastic is used. Three to four incheseach of the base and accelerator tubesare squeczed onto the mixing pad. It isthoroughly mixed as quickly as possibleand loaded into the tray. A cementspatula is used to mix the material.Seat with firm, but not excessive pres-sure. Experience will provide the rightbalance which will force the materialunder the gingival areas and still keepthe compound from touching the teethas little as po:sible. The tray is held inplace by the assistant or hygienist, leav-ing the orthodontist free at this pointto care for another patient. It is im-perative that the material be allowedto set in the mouth for at least sevenminutes, regardless of the manufac-turer's recommendations. It is extreme-ly important that the patient does notclose on the tray during the curingpcriod. A saliva ejector is recommend-ed to eliminate the need for swallowing.If large areas of compound show onthe finished impression, it indicates thatbiting of the tray has taken place. Theimpression is removed from the mouthwith a quick motion thereby preventingdistortion. Separation is replaced at theend of this appointment. Figure 2,taken of a completed impression, il-lustrates nicely the septum of rubberbetween each tooth. A close-up ofanother impression as seen in Figure3 was taken to show the feather edgesof material that extend beneath thecjngival margins.DLE CONSTRUCTIONRecent research indicates that rub-ber base impressions should be pouredwithin an hour to retain their accuracy.Formerly it was believed that the com-pleted impressions would remain dimen-sionally stable for long periods.Completed impressions are boxedwith a weather stripping compound.`They should be built up with strips ofmaterial to a height of thirty mm. asmeasured from the cusp tips. This willinsure dics of adequate length.Thc impression is then poured inFig. 2 Above, Fig. 3 Below. 118Lindquist April, 1959at the cervical region to extend thecrown portion three to five millimetersbelow the original gingival line. In-dividual dies are held in a vise andbands constructed. Upon completion ofbanding, the dies are re-assembled tothe original model. Brackets and tubesare placed where needed and initialarchwires and face-bow headgear con-structed, if desired. This synopsis wasgiven to clarify the procedure beforedescribing each step in detail.Fig. 4Devcon Plastic Steel. The resulting diesare composed of 80% steel and 20%plastic. Devcon consists of a putty-typematerial to which a liquid hardener isadded and the two thoroughly mixed.They are combined at a ratio of onetablespoon of putty to a teaspoon ofliquid. Two tablespoons of putty are~11 LLILllL fzr the ~~ver~ge imprewion.When mixed, the material has the con-sistency of a thick syrup. To insure bub-ble free models, a thin layer of thematerial is painted into the crowns ofthe teeth with a fine brush. Figure 4shows the material being painted intothe crown portions. Boxing materialwas removed to make the photographpossible. After a thin layer is present,the remaining material can be pouredinto the impression. A poured impres-sion is illustrated in Figure 5. Plasticsteel will harden in four or five hours.After this time, or preferably over-night, the model can be separated. Thecompound is re-heated to the originalworking temperature and removed. Therubber base material will peel off easily,unless the compound has been over-heated.At this stage we have a plastic steelmodel of each arch. This will be crack-ed apart to form individual dies ofeach tooth. The dies are then trimmed--.a:-:-..+Fig. 5 Above. Fig. 6 Center. Fig. 7 Below. VoI. 29, No. 2 Indirect Technic 1 I9Tapered sides are formed on the baseof the plastic steel model with an arborband on a lathe. Figures 6 and 7 showthe trimmed model. The base is lubri-cated with vaseline, or other separatingmaterial. The model base is insertedinto a mix of hydro-cal to a depth ofapproximately % of the total modelheight. The stone core or key that isthus formed is illustrated in Figures8 and 9. Upon removal from the core,the plastic steel model is separated intodies in the following manner. A ribbonsaw blade is passed between the con-tact areas and a cut made to a depthof approximately three millimeters.These cuts are extended on the labialand lingual of the model with a separat-ing disc or diamond disc. They are shal-low cuts not more than two millimetersin depth. The model is not cut apartwith the disc or saw; we are merelyestablishing cleavage lines. Thesecleavage lines are seen in Figure 10.A cutting plier is inserted into the shal-Fig. 8 Above. Fig. 9 Below. Fig. 10 Above. Fig. 11 Center. Fig. 12 Below. I20 Lindquist April, I959low cuts and the dies are cracked apart.It is vital to later re-assembly that thedies be cracked apart and not cut apart.A cross section of a die showing thecleavage lines and cracked surface isshown in Figure 11.A knowledge of dental anatomy isessential for proper trimming of thecervical portion of the dies. A steel vul-canite bur is used to trim this portionof the die. The crown is extended gin-givally three or four millimeters belowthe impression line. It is not difficultto accurately reproduce this portion ofthe tooth; the contours of the crownare followed and extended into thisarea. Some type of dust collection isneeded while grinding the plastic steel.A suction apparatus designed for thispurpose would be ideal. Small stepsor parallel lines are cut on the labialand lingual of the die base to enableit to be held in a vise. The dies canbe re-assembled into the stone core atany time and the original plastic steelmodel will be reproduced.BAND CONSTRUCTIONBands are constructed of chrome al-loys for many reasons; however, goldcan be used. Both straight bandmaterial and contoured blanks are used.Peak pliers are used to form the bandsas they are capable of stretching theband material around the contours ofthe teeth and make superior bands. Allband strips except lower anteriors areformed into a contoured convex blank.The ends are welded together and thecontoured blank is slipped over the die.The labial or buccal surfaces are adapt-ed to the die with a band pusher beforethe band forming pliers are used. Figure12 shows the completed pinch with thepliers. Note how carefully the band isadapted to the die at this stage. Uponremoval from the die, the band is weld-ed along the seam. On bell shaped teeththe welding spots are moved a milli-meter away from the seam. The ex-cess material is removed and the gin-gival margins are contoured or cut tothe desired shape. The band is return-ed to the die and the "tail" is foldedover. It is again removed and the"tail" welded to the lingual of the band.Figure 13 is a view of a completedmolar band. Anterior bands require thatthe pliers be modified to a convex in-stead of a concave beak. Howlett orAngle band-forming pliers may also beused. Brackets are pre-welded to allband strips except cuspids and molars.Brackets are angulated in most cases toproduce better control of axial inclina-tions; however, this is beyond the scopeof this paper. It is felt that more ac-curate bracket placement can be ac-complished by attaching the molartubes and brackets and cuspid bracketsafter the bands have been formed andre-assembled into the original model.'DIE RE-ASSEMBLYAt many times during the band for-mation process the dies are re-assembledinto the stone core. Bracket height canbe easily checked. Occlusal interfer-ences with band placement and bracketand tube placement can be checked andcorrected if needed. Re-assembly iscompletely accurate; in fact fixedbridges can be made and assembled onmodels such as these.Molar tubes can be tack welded tothe bands by the technician as well asmolar and cuspid brackets. It is possiblefor the orthodontist to angulate theseattachments if desired without remov-ing them from the bands. If they areincorrectly located, they can be twist-ed off and relocated in correct positionsby the technician. This is a tremendousadvantage and is possible only by usingchrome alloys. Chrome-nickel alloysmake possible the soldering of tubesto bands after they have been tack weld-ed in proper position. Tube placement Vol. 29, No. 2Indirect Technic121by this tack welding and soldering oper-ation is usually more accurate thanusing tubes with welding flanges.It is easy to visualize how the com-plete appliance can be constructed bythis method. Band accuracy is suchthat almost every band will fit the toothin the same relationship that it does onthe re-assembled model. Initial arch-wires are formed on these models afterall bands and attachments are com-pleted. Auxiliary .045 tubes can besoldered to the upper first molar bandsand a complete face-bow headgear as-sembled from this same model. In timewe may be able to construct all archwires needed during treatment beforethe first band is cemented. Laboratorytime will be increased, but chair timedrastically decreased. It is possible thata whole new era in orthodontics couldbe introduced by widespread adoptionof indirect procedures. Figures 14 and15 are photographs of a completededgewise appliance on the re-assembledmodel.BAND FITTING AND CEMENTATIONVery little fitting is required. A Hol-lenback pneumatic condenser is usedto seat the bands. These bands fit inevery sense of the word. If properly con-structed on the dies, there is no "rockor roll" to them. They go to one posi-tion and only one. The cervical fit is ofprime importance. Bitewing x-rays willreadily convince one of the superiorityof the bands in this respect. If a steelband is too large, it is a simple matterto cut it in two on the lingual, overlapthe required amount, and weld backtogether. The contour and fit is not de-stroyed by this process. If a band is toosmall, it may be stretched slightly withband stretchers to the desired size. Thisis necessary only when the dies are in-correctly trimmed, which seldom hap-pens. Bands are cemented a quadrantat a time. With this outline of the pro-Fig. 13 Above. Fig. 14 Ceirter. Fig. 15 Below.cedure completed, a brief outline of theadvantzges of chrome alloys will begiven.ADVANTAGES OF CHROME ALLOY1. Stronger bands - better edge2. Better fit - retains contour better.strength. 122 Lindquist April, 19593. Takes and retains mirror brightfinish.4. Stretches over a die or tooth duringband formation without breaking,and thus gives a better fitting band.The Peak pliers utilize this qualityto the utmost.5. Allows brackets and tubes to be tackwelded for a trial fitting or inspec-spection. If they are not right theycan be twisted off and re-positioned.This is a big advantage since auxil-iary personnel place the attachments,but the orthodontist has a finalcheck before they are completelywelded.6. It is much easier to train auxiliarypersonnel in welding techniques thanin soldering. Welding with the newerwelders is almost foolproof. Solder-ing, as we all know, takes quite alittle practice.In closing, a summary will be given ofthe advantages and disadvantages ofadapting this indirect appliance con-struction method to a busy orthodonticpractice.ADVANTAGE s AND DISADVAN TAG,ESAdvantages :1. It is much kinder to the patient.Think how much easier it must befrom the patient's point of view tohave a set of impressions taken, a lit-tle band fitting, and then have theirappliances cemented. Contrast thisto the tearing of the gingival attach-ment and malleting that are in-evitable with direct methods. Thisconsideration of our patients is in myopinion the number one advantageof this method.2. It is much easier on the orthodontist.Much of the fatigue, both mentaland physical, is taken from bandconstruction.3. It takes less time. The exact amountof time will depend on the speed ofthe orthodontist but this methodshould reduce chair time by morethan fifty per cent.4.. It results in a superior appliance.Both the bands and the accuracyof attachments are improved.5. It is tailor made for the use ofchrome alloy. The advantages of thishave been explained.DISADVANTAGES1. It requires the services of a trainedtechnician, either male or female.Every busy practice should be ableto absorb a full time technician, notof course for band making alone,L-- r-..of practice that someone else can betrained to do as well as we woulddo it ourselves.2. It involves an extra step of chairtime. The time it takes for the +-pressions is, however, quickly savedduring the later stages.3. The adoption of this method re-quires a change in the office routine.Progress however stops for no one.It is economically unfeasible to bothpatient and orthodontist to have theorthodontist do things which auxil-iary personnel can be trained to do.UUL lU1LllC IIUIIIClUUL UCIICl phases3311 N. Meridian St.