The FDA under attack. Following an unbiased article* on the matter published in the New York Times, November 10,1999, National Desk entitled "'Single Use' Medical devices are often used several times" and probably in preparation for the FDA public meeting on medical device reuse on December 14 1999, the trusts which manufacture and distribute most of the medical and pharmaceutical products have recently started a new campaign against recycling. As in the past, both TV (CNN) and some from the press have accommodated their patrons, accusing FDA of exposing patients to the risks of recycling. Thus, USA Today on November 29 and 30, 1999, has published two articles entitled "Hospitals reuse medical devices designed for onetime use only" and "FDA exposes patients to risks of medical recycling". While both articles were long, the space given to opposing views was minimum. There were three cases presented: a. five infants developed lung infections linked to the reuse of syringes, b. a heart patient was partially blinded by the rupture of a reused balloon catheter, c. a woman developed an abdominal infection when a reused guide wire broke off in her throat. Noted was the fact that somewhere from 31% to close to 100% of the nations hospitals reuse disposable devices, saving in the process hundreds of thousands of dollars a year. Realizing that the practice is too widespread to ban , the first article suggested to at least inform th epatients, to have the hospitals and third party reprocessors registered, to require manufacturers to explain why it should be labeled as single use, to have both manufacturers and reprocessors finance FDA-sponsored research, and finally, to have both of them submitting data on adverse events generated by reuse. In the second article, the FDA is accused of standing aside as perhaps thousands of hospitals have reused disposable medical devices for the past 22 years. The article cited the same cases, and charged that while in other cases, the FDA has been quick to react, in this particular case it has neither registered nor inspected thousands of reprocessors. According to the article, only eight companies that reprocess disposables for hospitals have registered with the FDA, as required by law...

___.The opposite views belonged to the Executive Director of the Association of Medical Device Reprocessors and to the Director of the FDA. The former stressed the point that medical devices have been safely and effectively reprocessed for more than twenty years, saving hospitals millions, and that the manufacturers' concern is money: "they forget to say that the 'single use' label is not a government requirement, but rather their choice".The FDA's director showed that the adverse effects associated with medical devices rarely indicate that reused single-use equipment poses a special health hazard, and that the FDA has developed a strategy that requires re-manufacturers to submit an application for premarket approval for higher risk devices, while the low risk devices may be exempted from the premarket review. At the same time, however, it requires the original-equipment manufacturers to indicate on the label the reason a product is intended for single use.
Prefiguring the future. According to its past president, Dr. Lawrence Kessler, quoted in one of the articles, "what FDA needs to do is to help take the leadership role in creating a shared vision for what (the practice) should look like in five or ten years". We believe that the FDA has taken the proper course. It is very unlikely that in the future we will continue to freely dispose of everything, especially of the materials which become toxic when dumped (in the absence of oxygen, stainless steel releases Cr and Ni ions in the subterranean water). The present status of technology not only allows the proper inspection and decontamination of all metal items, but can provide a badly needed critical evaluation, as shown in the next article. In addition, the higher the level of civilization of a society, the more it recycles, in some instances reaching the unthinkable, as shown in Fig.1. The image, taken from Skylab II, captures an astronaut while feeding the drinking water generator.
___.On December 14, 1999, in Rockville, MD, the FDA had an open meeting regarding it strategy on the reuse of "single use"devices. Ortho-Cycle' s representative, Eng. Eugenia Matasa was among the about 200 participants and one of the 28 who made a formal oral presentation. The powerful Original Equipment Manufacturers association (OEM, which very probably comprises the Orthodontic Manufacturers Association, OMA) demanded the FDA to finalize as soon as possible its strategy. Several voices, including Ortho-Cycle's have shown that OEM tries to limit their liability (and curb reuse) by labeling their products as Single Use Only without any explanation. Our company's presence there was out of place: the problems discussed were at the level of pacemakers, angioplasty balloons, catheters, etc., all being intensively reused in hospitals, while orthodontic brackets were far away from any concern.
___.As these are we do not reconstruct or repair them, but clean,decontaminate inspect and sort them using Good Manufacturing Practices, we should have been the least concerned with this meeting.
Braces are medical devices too! This is not, however, what OMAthinks. Still reeling from its previous attempts to curb loses due to recycling, it has sent a diskette entitled "OMA Statement on Recycling and Reuse of Orthodontic Devices" to selected orthodontists. This rehashed version comes years after Ormco has sued Ortho-Cycle Co. for... patent infringement (Case 95-0847, 1996, Los Angeles, CA), abandoning its suit just before trial, and after a highly biased NBC-TV Dateline's broadcast that forced the American Association of Orthodontists to state that reconditioned brackets "are safe and effective". The broadcast "has generated little interest, the AAO receiving few calls from consumers"¹. US is not alone in this: a survey of 300 members of the British Orthodontic Society showed that 47.5% of respondents recycled metal brackets².
Ortho-Cycle's compliance. As mentioned years ago³, we are proud to be called "the final inspector", being a real filter against lemons. Despite high cost, we inspect the appliances under different magnifications, selecting out not only those which have been damaged during treatment and debonding, but also those which were inappropriately released by the manufacturer which we return as damaged. Therefore it is highly unlikely that any other appliance would ever be subjected to more decontamination than ours. After a first step in which the breakage of the C-C bonds needed to remove the adhesive destroys any living organism, all attachments are once more autoclaved just before being packaged, sealed and shipped. Comparing safety requirements vs. Ortho-Cycle's performance, it is obvious that we went overboard in fulfilling both the FDA (we were registered in 1991) and ISO 9002 requirements. While still striving for the latter qualification, our refurbished orthodontic appliances were found years ago to be "substantially equivalent to the legally marketed predicated devices"⁴. Since then, due in part to the many inspections to which we were subjected, performed at the federal, state and local levels, we are now in the position to thank for our present compliance to those manufacturers who have repeatedly singled-out us as the lightning rod for the orthodontic reconditioners. According to the FDA, the least hazardous devices are in class I. This category includes non-plastic orthodontic braces: their lack in potential hazard is underlined in 21 CFR Parts 862-892, as published in the Federal Registers of December 7, 1994, and January 16, 1996 which exempts them from both a premarket notification requirement and an FDA clearance as long as the Good Manufacturing Practices (GMP) are followed. In Florida, a reprocessor has to comply with the same requirements as a manufacturer, and our licence⁵ states that we are "device manufacturers". In other words, while other reprocessors are not even registered, we have exceeded the present regulations by fulfilling all the premarket requirements although exempt, and are under the same scrutiny as any of the new-devices manufacturers...
___.Leaving aside the fact that for many years we only cleaned, inspected, sorted and decontaminated appliances, without interfering with their original shape and form, but we also researched the way our refurbished attachments reach their destination. Sent sealed by mail, those arriving at clinical laboratories having addresses closer to us were found still sterile⁶, which is a quality assurance bonus for both us and the shipping company.
Are manufacturers compliant? Judging from their actions, one might believe that the attachments sold by the original manufacturers are properly decontaminated against the possible diseases the workers can bring to the attachments. While manufacturers claim that a decontamination is unnecessary, the attachments being new, we seriously question this. Indeed, these are assembled, one by one and in close proximity, in countries where health standards are poor. Concerning evidence of a possible decontamination, the examination of the plastic packaging commonly used leads to the conclusion that these items couldn't have resisted the harsh conditions imposed by heat sterilization.
___.In contrast to the case of drugs and Western European regulations, in the US the disclosure of the composition and the processing of the orthodontic appliances is not compulsory. As a result, brazing materials containing cadmium or beryllium⁷, both known to be toxic, were used, or at least patented. In addition, the brackets detachment from their bases, Fig. 2, is a nonevent. When the brazing alloy is nobler than steel, e.g. gold based, galvanic corrosion leads to the steel dissolution, Fig. 3. Stainless steels such as AISI 303 (which contains sulfur to allow an easy machining) are currently used, while having been prohibited in Germany for for years8. The result is that today there are brackets which practically dissolve in the mouth, Fig.4, the nickel ions released being ingested by the patient. As manufacturers use only a statistical inspection of the attachments (some ten to maximum a hundred out of a thousand), incredibly defective samples are continuously released, Fig. 5. Even in the Iowa University study used by OMA to discredit reconditioning⁹, a brand new bracket tested had mean slot size of .0187 instead of .0180, which is far from the manufacturers' claim that "the variation in the slot size for different manufacturers ranged between .0000 and 0.0002. Under oath, Dr. P. Kesling from TP Orthodontics, prominent member of OMA, has declared: "I don't think I would know the difference if I had a .0025 or a .005% difference. Not significantly different"¹⁰.
___.While brackets without slots or tie wings can be easily observed, more insidious errors can make the treatment go awry. The crucial part of the bracket, its slot, can be often found not only out of its prescribed size, but cut the reverse way, as shown by the bicuspid in Fig.6 where the gingival extension opposes the torque. Improperly marked brackets are encountered even by far more often: we had to discontinue paying our technicians $5 for each lemon found as this may have ruined us...
___.Through the years, we have published a series of articles on the defective brackets found¹⁰ , pointing out the source of the error, in the belief that this situation would be corrected. Unfortunately, this didn't happen in fact, which leads us to the following...
References
1. American Assoc. of Orthodontists 1997-8 Annual Report
2. Oliver RG, Greenslade M, Harkness M, Patient and parent opinion of the reuse of recycled orthodontic brackets: an international comparison. Brit. J. Orthod. 1997; 24: 329-332
3. Matasa CG, How do reconditioned brackets compare with the new ones? The Orthod. Materials Insider, 1996: 9 (4): 3-5
4. FDA, Dept. Health &Human Services, Permit K 913913, 1991
5. State of Florida, Dept. of Health, Drugs & Devices Permit No. 08:1718
6. Micrim Labs. Inc., Reports 98A919; 98A920; 98A921, 1998, Ft. Lauderdale, FL
7. Ormco Corp. US Patent 5,254,003, 1993
8. Bundesgesundheitsamt (BGA), Legierungen in der zahnarztlichen therapie, Hellmich KG, 1992, Koln & Munich
9. Matasa CG. The anatomy of a mistrepresentation (relates to the Iowa University study as reported by OMA). The Orthod. Materials Insider 1996; 9:2-5
10. DM Fox vs. TP Orthodontics, Case 3:97CV181, US District Ct., Richmond, VA
11. Matasa CG, Flaws in bracket manufacturing, J. Clin. Orthod. 1990; 24(30:149-152; Fallas sistematicas en la fabricacion de los brackets de pegado directo, Ortodoncia (Buenos Aires) 1991; 56(109):5-10; Defend yourself against faulty appliances. I Faults due to poor manufacturing, J. Gen. Orthod.1991; 2(4):5-9.

DOC, I'M ALLERGIC TO METALS!
A new, do-it-yourself test is incredibly simple

ABSTRACT
___.The evaluation of the nickel released by stainless steel appliances is of increasing importance as the younger generations are more prone to allergies than the older ones. The only method addressing the problem is both sophisticated and expensive.
___.The method presented in our last issue as applied to attachment coatings -gel chromatography- is now extended to the detection of the nickel released by different brands of direct bonding brackets, new and worn alike. The test uses the same agents as a German test adopted by ISO which is currently used for the stainless steels used in dentistry. This simple and inexpensive method can be used to disclose in advance with both consistency and accuracy the attachments which could produce allergies.
INTRODUCTION
___.Having a toll-free phone number used by numerous clinicians for consultations regarding the biomaterials used in orthodontics, we are often asked for an opinion on which metal attachment could lead to fewer problems. Till now, the answer was either to check with the manufacturer on the nature of the steel used (with dubious results) or ask for a test according to a practically unknown Japanese standard, the only one addressing the matter.
___.A combination utilizing the same agents used in accelerated tests adopted as standards and a technique used in analytical chemistry has now allowed us to solve the problem without having to use uncommon and expensive equipment.
Limited choices. Titanium brackets are biocompatible, but unsightly when compared with the plastic or ceramic ones. The plastic ones become yellow in time and their slot often creeps, while the ceramics may break the enamel at debonding time, if these didn't already break at the time you have applied a torque. Composite brackets may be the answer, but it is too early to tell. As a result, over 99% of the brackets sent to us from all over the world either for sale or reconditioning are made of stainless steel. For the lay person, stainless steel is a specific alloy: for the knowledgeable one, there are at least ten types currently used to make orthodontic appliances. Add to this three different ways of manufacturing them (milling, casting and injection molding) as well as another three different ways to put the parts together (welding, soldering and brazing). The brazing filler can be either less noble than stainless steel, or nobler. As the resultant system of two joined metals with an electrolyte solution (saliva) is similar to a galvanic cell, in the first case the metal filler will dissolve, leading to the detachment of the bracket from the base. In the second case, common today due to gold-based brazing fillers, the stainless steel bracket or the base dissolves. In both cases, heavy metals are released into the patients body.
___.Since we live in an imperfect world, for the time being the orthodontist has still to stick to stainless steel brackets. Indeed, both nickel and chromium are allergenic, the first metal affecting up to 31.9% of females¹ and potentially leading even to tissue necrosis^2,3. More over, this sensitivity has been found to increase in the younger generations⁴.
Standards measuring nickel. As we have shown in our previous issue⁵, there is no standard or accepted method to evaluate the nickel leached by the orthodontic appliances. Two countries have adopted an accelerated corrosion test based upon an attack with diluted lactic acid, as compared with our previously published method which uses diluted muriatic acid⁶. While our method measures the corrosion susceptibility by the hydrogen evolved, both the German and the Japanese tests use atomic absorption spectroscopy to measure the nickel released. The German standard⁷, adopted by the ISO, is recommended only for the stainless steel alloys used in dentistry, and cannot be applied to brackets, as it starts from sheets of metal of a certain size. In contrast, the Japanese one8 is designed to analyze a single bracket, disregarding its size or shape. While the concept is sound, as what is desired is the amount of Ni released, irrespective of other criteria, it is dubious from the statistical point of view.
Nickel testing is not cheap. Leaving aside the disadvantages mentioned, the average cost of a single atomic absorption spectroscopic test according to the German and Japanese standards averages $100. In addition, the progress of the corrosion (i.e. the solubilized nickel) cannot be followed unless many sequential samples are taken. The known chemical tests are equally unfit, as these require an alkaline environment which doesn't match accelerated corrosion tests based upon an acid attack. Thus, while both rubeanic acid (dithiooxamide) and dimethylglyoxime combine with nickel to give a blue and a bright-red precipitate, respectively, both reactions occur only in the presence of ammonia⁹.
___.Solubilized iron reveals nickel. While for the lay man, analyzing the nickel content is all that counts, for the engineer this direct approach is too cumbersome. Indeed, in solid solutions, which is not the case with stainless steels, it is possible to have one of the components of an alloy dissolving preferentially, a process known as dealloying. In contrast, stainless steels have an intimate structure in which part of the Fe atoms in the lattice are substituted for Ni and Cr. This structure, shown in Fig. 1, is so tightly knit that it cannot release one of the elements without releasing the others in exactly the preestablished proportion found in the unit cells. In other words, for a certain stainless steel, it suffices to measure only one of the solubilized elements to know how much of the others have been released. While this proportion is not the same in all steels, the other factors which influence corrosion susceptibility are prevalent. Thermal treatments may generate carbides or sigma phases, the mechanical one may transform austenite in martensite while impurities and galvanism may play havoc with a steel which otherwise would have been corrosion resistent.
MATERIALS AND METHOD
___.To analyze the solubilization of nickel by following that of iron, a method based upon gel chromatography has been developed. This was possible because it was found that a typical reagent for iron, potassium ferrocyanide, gives its intense blue color unhindered by even the presence of all the ingredients needed for the test. Thus, according to the German formula, 0.1 mol each of lactic acid 85% (CAS 50-21-5) and sodium chloride (CAS 7647-14-5) were dissolved not in a liter of distilled water, but in the same volume of a mixture 3:1 mixture of water with glycerol, agent added to reduce water evaporation. To this we added 10 mls of an aqueous solution 1% of potassium ferrocyanide and 50 gms Aerosil 200 (Degussa), a fine silica known as a gellifying agent for water-based solutions. The whole mixture is then homogenized in an epoxy coated Hobart mixer . The coating is needed to prevent both the attack of the stainless steel container and the coloring of the gel. In each of a series of common plastic drawer organizers (Rubbermaid, 9x 6x 2 inch), all free of any metal contamination, we pouredf 200 ml each of the gel. After being degreased with a solvent (e.g. such as those used to remove nail polish, in our case ethyl acetate), the attachments are placed one by one in the gel, taking care to have them properly immersed. To enhance contact, the gel is vibrated for few seconds and then left for three days or less, i.e. till blue spots radiate around the attacked brackets. At the end of the desired period, the diameter of the spots formed around each bracket was measured and the results were statistically processed and compared.
RESULTS
New brackets. Twenty sets of direct bonding brackets selected from different lines and manufacturers were taken from their original packaging as shown in Fig. 2 and were placed in twenty organizers (or trays) in which two liters of gel were equally distributed. The brackets were left in the gel for forty eight hours at room temperature and then photographed with a Nikon Cool Pix 950 digital camera.
___.The brackets tested were Unitek, Twin Torque (mesh base); Lancer, Sinterline; American Orthodontics, Master Series (Alexander prescription); "A"-Co., MiniTwin; Scheu Dental (Germany), Mezanium; GAC, Accuarch; "A"-Co,. Alexander, (Mini); Unitek,Twin Torque (Dynalock base); American Orthodontics, Mini Master Series; Unitek, Miniature Twins; Ortodent T (Russian); Unitek, Victory; Unitek, Mini Unitwin (Dynalock base); Rocky Mountain Orthod., Minitaurus; Forestadent, Mobil-Lock; Pumpa (Russian); American Orthod., Master Series, twins; Ormco, Style; Alpha Orthodontics, One piece (France); GAC, Microarch.
___.Although the attacking agents were diluted (only 1.1% lactic acid and 0.6% table salt), almost all brackets generated some circumferential staining, and a few did so almost immediately. While most of the brackets from the same brand & line behaved the same way, showing consistency, marked differences were found between brands, as shown in Fig. 3 As our goal is not to discredit brands, but to provide useful information for the clinician who wants to reduce risks, the brands & lines which gave the smallest spots (i.e. leached less iron, and implicitly less nickel) were the following: Scheu Dental's Mezanium, "A"-Co.'s Alexander Mini, Unitek's Miniature Twin and Victory.
___.A similar test of worn brackets (as received from clinicians who do not recycle but offer them for sale) was performed. All the brackets had adhesive on them, a fact which renders them more pron, as compared with the brand new ones, to crevice corrosion. The twenty brands and lines tested shown in Fig. 5 were, in order: Ormco, Diamond; Unitek, Miniature Twin; Unitek, Mini Unitwin; Forestadent, Twins; Ortho Organizers, Elite Mini Twin; American Orthodontics, Triple Action; Dentaurum, Ultra Mini Trim; Unitek, Dynalock; Unitek, Twin Torque; Ormco, Mini Diamond; "A"-Co., Standard Twins; GAC, Accuarch; "A"-Co., Damon; American Orthodontics, Master Series; "A"-Co., Mini Twin; Lancer, Sinterline; Orec, Speed; Unitek, Glance. Among these, little or almost no spots were shown by the following: Unitek's Miniature Twin and Twin torque; Ortho-Organizers, Elite Mini Twin; Ormco, Mini Diamond and "A"-Co., Mini Twin.

DISCUSSION
___.While all the brackets tested led to spots after several days , the size of the latter was significantly different, showing that some brands leak heavy metals more than others. Within the same group, the brackets belonging to a certain line behaved consistently, the exceptions being few. As expected, brackets using large parts made of other alloys than stainless steel (Mobil Lock, Fig. 3 #15) showed extensive corrosion. Difficult to explain were the large spots exhibited by "A"-Co. Standard Twins (Fig. 5#11). According to the manufacturer, these are made of AISI 316L, a highly corrosion resistant steel which proved to be the best in our previous tests based upon the attack with muriatic acid6. These brackets were subjected to the test before any recycling by us,or by the clinician whom was purposely contacted. Their strange behavior can be explained only by exposure to a temperature at which chromium carbide or sigma phases develop in the steel, i.e. well above the temperature we use to remove the adhesive or to sterilize.
Surprising was also the good behavior of Scheu's brackets, despite their large content of manganese which was a liability in our previous tests usingdiluted hydrochloric acid.
CONCLUSIONS
___.This do-it-yourself test allows the selection of the stainless steel attachments that, according to the only official tests known, leach the lowest amount of heavy metals. While it cannot provide the exact amount of nickel released, it can be used to compare brands as long as an acceptable standard (sample) is available. Aside from the brands indicated as leaching less metals, the test allows to rank others by comparison. Thus, if the same conditions are used and the stain of a new brand is larger than that of the standard sample, the choice may lead to increased chances for allergies.
___.The test is at everyone's disposal who wants to try, the means to examine at practically no cost, a variety of attachments. If we had paid a laboratory to determine the nickel per the Japanese method (specifically designed for brackets) for the number of brackets examined (two times twenty trays with twenty brackets each, plus another one time nine trays with twenty brackets) we would have paid almost a million US dollars (each test $100). Samples of this gel have already been offered free ("The gel will tell!) at Ortho-Cycle's booth at the AAO Annual Meeting in San Diego, May 1999: see further the offer & coupon below...
References
1. Bass JK, Fine H, Cisneros GJ, Nickel hypersensitivity in the orthodontic patient, Am J Orthod Dentofac Orthop 1993; 103: 280-5
2. Peters KP, Heese A, Allergie gegen Metalle in der Zahnheilkunde, Tagung de DGKMZ (German Academy for Dentistry), Wiesbaden, 1995
3. Levy A, Hanau D, Foussereau J, Contact dermatitis in children, Contact dermatitis, 1980: 6: 260-4
4. Gjerdet NR, in Dental materials, Biological properties and clinical evaluations, I.A. Mjor, ed., CRC Press, Boca Raton, FL, 1980: 165
5. Matasa GC, The wear and corrosion resistance of metal deposits, Orthod. Materials Insider 1999; 12: 3, 1-8
6 . Matasa CG, Orthodontic attachment corrosion susceptibilities, J. Clin Orthod. 1995: 29(1): 16-23
7. International Standards Organization #6871-2; 1996
8. Ministry of Health and Welfare of Japan, Standard 1985.3.30 No. 294
9. Lewis CL, Ott WL, Analytical chemistry of nickel, Pergamon Press, Oxford 1970.
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