- Email: [email protected]
A discussion of orthodontic materials
84
The
F01'U1n
A Discussion of Orthodontic Materials In his paper " Standa rds for Orthodontic Materials " published in the I NTERNATIONAL JOURNAL OF ORTHODONTIA, November, 1935, 'Wilmer Soud er discusses the r elative properties of present orthodontic materials. With r egard to the base metal alloys (stainless steel alloys) r eference is mad e to their yield point being below the minimum specifications of 125,000 pounds per square inch. Further st at ement is made to th e effcct that no gr eat amount of time has been spent at the Bureau upon th ese metals (sta inless steel) , since they do not appear to possess sup eri or ph ysical properties and since th ey possess some definitely inferior proper ti es. H e also mentions that " in th e ease of const ruction and mechani cal properties the gold alloys ar e unique." I respect highly the source from when ce this information comes. I am of the opinion, however, that the profession of orthodontia is not going to r est the case upon such sta tements, especially in th e light of the fact that "no gr eat amount of tim e has been spent at th e Bureau upon these metals. " About three years ago I began to u se th ese base metals, first stainless steel (so-called) and t hen later chr ome alloy 18 :8, an d gradually I increased their use until for th e past two years I have employed th em to th e exclusion of th e gold alloys. In th e light of this experience to date I would not change back to th e gold alloys even though gold alloy and chrome alloy cost the same. Taking into considera tion th e scr ap value of th e gold alloys th er e is perhaps very little differ ence in the ultimate cost to th e orthodontist. The ease and the speed of mani pulation th at spot welding affor ds in all band constructi on, togeth er with facilities afford ed through spot welding of attachments to bands on posterior as well as anterior teeth, and also the increased value of ret ention of t hese bands when cement ed to the teeth , leave no doubt of the superior qualities of th ese mat eri als. I hav e never found th e method as advocate d by the 100 p er cent spot weldin g enthusiasts entirely sat isfactor y for attaching small gauge wires to larger gauge wires or , for that matter, for attaching wir es of th e same gauge . 'V e still, however , have t he solder ing t echni c t o fall back on. This is quite simpl e and, in fact, is easier than soldering gold alloys. K eep the material out of th e flame, fr om Vs to % inch above, u se a dull point flame (not shar p) by cutt ing down th e ail' pressure, pl enty of flux and a r elatively high carat solder, prefer ably 18K. I find that with 18K solder I obtain a much st rong er soldere d attachment with no corrosion at th e joint an d only a slight t arnish that would normally be expected from the solder on gold alloy. We do not, however, h ave to solder if we so elect. With a little in genuity one can const r uct an entire lingual arch including posts, locks and all manner of auxiliary springs f rom two pieces, even from one piece, of wire. "When more than one wire is used, the auxilia ry springs are attached to the base wir e by a meth od of wrapping. Likewise labial ar ches can be so constructed in one piece by use of open loops and th e bending (through heat tr eat ment ) of the wir e upon itself to form hooks, spur s, et c. Sp ace prohibits at this time any detailed description of technic.
Th e Forum
85
'When chr ome alloy receives the same care in its finish an d final polish as any other metal should receive befor e heing put int o a person 's mouth, I cannot conceive of a bet ter substitute. Among other properties which it possesses over th e gold all oys, is a gr eate r tolerance of t he gingiva and soft ti ssues of the mouth th an that t o gold alloys. Ther e is a freedom of adhere nce of plaques and debris to thi s metal t ha t gold does not hav e. In ad dition to the aforementioned su perior qualiti es of this metal, I find that I can construct appliances in about one-t hird to one-half less ti me, which is a decided economic adva ntage to the busy orthodontist. Also th e f requency of treatment is lessened on account of greater flexihility of appliances made possible by the use of smaller gauge wires. Much good can accr ue t o the practice of orthodontia by further discussion of this subject by orthodonti sts at lar ge and by th e publicati on of furt her investi gati on from the Bureau of Standards. I should like to see fur ther comment on this topic th rough this department of the Journal. - H owar d Yo st.
The
F01'U1n
A Discussion of Orthodontic Materials In his paper " Standa rds for Orthodontic Materials " published in the I NTERNATIONAL JOURNAL OF ORTHODONTIA, November, 1935, 'Wilmer Soud er discusses the r elative properties of present orthodontic materials. With r egard to the base metal alloys (stainless steel alloys) r eference is mad e to their yield point being below the minimum specifications of 125,000 pounds per square inch. Further st at ement is made to th e effcct that no gr eat amount of time has been spent at the Bureau upon th ese metals (sta inless steel) , since they do not appear to possess sup eri or ph ysical properties and since th ey possess some definitely inferior proper ti es. H e also mentions that " in th e ease of const ruction and mechani cal properties the gold alloys ar e unique." I respect highly the source from when ce this information comes. I am of the opinion, however, that the profession of orthodontia is not going to r est the case upon such sta tements, especially in th e light of the fact that "no gr eat amount of tim e has been spent at th e Bureau upon these metals. " About three years ago I began to u se th ese base metals, first stainless steel (so-called) and t hen later chr ome alloy 18 :8, an d gradually I increased their use until for th e past two years I have employed th em to th e exclusion of th e gold alloys. In th e light of this experience to date I would not change back to th e gold alloys even though gold alloy and chrome alloy cost the same. Taking into considera tion th e scr ap value of th e gold alloys th er e is perhaps very little differ ence in the ultimate cost to th e orthodontist. The ease and the speed of mani pulation th at spot welding affor ds in all band constructi on, togeth er with facilities afford ed through spot welding of attachments to bands on posterior as well as anterior teeth, and also the increased value of ret ention of t hese bands when cement ed to the teeth , leave no doubt of the superior qualities of th ese mat eri als. I hav e never found th e method as advocate d by the 100 p er cent spot weldin g enthusiasts entirely sat isfactor y for attaching small gauge wires to larger gauge wires or , for that matter, for attaching wir es of th e same gauge . 'V e still, however , have t he solder ing t echni c t o fall back on. This is quite simpl e and, in fact, is easier than soldering gold alloys. K eep the material out of th e flame, fr om Vs to % inch above, u se a dull point flame (not shar p) by cutt ing down th e ail' pressure, pl enty of flux and a r elatively high carat solder, prefer ably 18K. I find that with 18K solder I obtain a much st rong er soldere d attachment with no corrosion at th e joint an d only a slight t arnish that would normally be expected from the solder on gold alloy. We do not, however, h ave to solder if we so elect. With a little in genuity one can const r uct an entire lingual arch including posts, locks and all manner of auxiliary springs f rom two pieces, even from one piece, of wire. "When more than one wire is used, the auxilia ry springs are attached to the base wir e by a meth od of wrapping. Likewise labial ar ches can be so constructed in one piece by use of open loops and th e bending (through heat tr eat ment ) of the wir e upon itself to form hooks, spur s, et c. Sp ace prohibits at this time any detailed description of technic.
Th e Forum
85
'When chr ome alloy receives the same care in its finish an d final polish as any other metal should receive befor e heing put int o a person 's mouth, I cannot conceive of a bet ter substitute. Among other properties which it possesses over th e gold all oys, is a gr eate r tolerance of t he gingiva and soft ti ssues of the mouth th an that t o gold alloys. Ther e is a freedom of adhere nce of plaques and debris to thi s metal t ha t gold does not hav e. In ad dition to the aforementioned su perior qualiti es of this metal, I find that I can construct appliances in about one-t hird to one-half less ti me, which is a decided economic adva ntage to the busy orthodontist. Also th e f requency of treatment is lessened on account of greater flexihility of appliances made possible by the use of smaller gauge wires. Much good can accr ue t o the practice of orthodontia by further discussion of this subject by orthodonti sts at lar ge and by th e publicati on of furt her investi gati on from the Bureau of Standards. I should like to see fur ther comment on this topic th rough this department of the Journal. - H owar d Yo st.