British Journal of Orthodontics
ISSN: 0301-228X (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/yjor19
Recycling Bands and Brackets K. M. Postlethwaite B.D.S., M.Sc., M.Orth., R.C.S., F.D.S., R.C.P.S. To cite this article: K. M. Postlethwaite B.D.S., M.Sc., M.Orth., R.C.S., F.D.S., R.C.P.S. (1992) Recycling Bands and Brackets, British Journal of Orthodontics, 19:2, 157-164, DOI: 10.1179/ bjo.19.2.157 To link to this article: http://dx.doi.org/10.1179/bjo.19.2.157
Published online: 21 Jun 2016.
Submit your article to this journal
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Citing articles: 9 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=yjor19 Download by: [Tufts University]
Date: 22 November 2016, At: 08:56
British Journal of Orthodontics/Vol. 19/1992/157-164
Orthodontic Materials Update Recycling Bands and Brackets K. M. PosTLETHW AITE, B.D.S., M.Sc., M.ORTH., R.C.S., F.D.S., R.C.P.S. ?rth?donti~ Department, Floor 22, Guys Tower, London SE19RTand Dental & Maxillofacial Department Hospital tor Sick Children, Great Ormond Street, London WClN 3JH '
Introduction
Following the advent of direct bonding during the 1970s, techniques evolved for recycling brackets so that they could be reused, thereby reducing the cost per case. During the 1980s, the number of brackets being recycled increased, with many recycling companies becoming well established in the United States and the United Kingdom. Now, during the early 1990s, 75% of American orthodontists are recycling some of their bands and b~a~kets (Lewy, 1991 ). Even though recycling has d1stmct economic advantages, many orthodontists continue to have reservations about it. Firstly, almost all of the orthodontic manufacturers state that their products are for single use only, and print a disclaiming notice which is attached to their products, stating that no liability will be borne by the company if their products are reused. Secondly, there are concerns about the possible increased risk of cross infection if recycled products are used (Unkel, 1987). Thirdly, orthodontists seek reassurance that the quality of the recycled product is satisfactory, with a clinical performance similar to the new product and with equally low rates of bond failure. Finally, there are fears that litigation could result from the use of recycled products if it could be proved that failure of an appliance, substandard orthodontic treatment or cross infection was attributable to use of a recycled product. In this paper, the methods and effects of recycling are reviewed, and the services and prices of several companies in the United Kingdom and the United States are compared. Methods of recycling
The aim of any recycling system is to completely remove adhesive from the bracket without causing damage to the bracket base, so that the bracket can be rebonded to enamel producing a new adhesive 030 1-228X/92/002000 + 00102.00
bond of adequate strength. There are two main methods of recycling in use: (1) Application of heat to burn off the adhesive and (2) Use of chemical solvents to strip off the adhesive (Zachrisson, 1985).
A? ex_amp~e of the first method, relying on heat application, IS the recycling process used by the Esmadentcompany, whilstanexampleofthesecond method using chemical solvents is the process used by Orthocycle. Both of these methods have been investigated fully. (Buchman, 1980; Hixson et al., 1982; Mascia and Chen, 1982; Smith, 1986; Regan et al., 1990) With the Esmadent system, the brackets are heated to 454°C for 45 minutes. Following this, the hot brackets are immersed into a cold cement solvent and ultrasonically cleaned for 10-15 minutes. The brackets are then washed, dried and electropolished for 30-45 seconds. Brackets are then placed in sodium bicarbonate solution to neutralize the electrolyte, followed by hot water rinsing. 50 microns of metal are removed by this method. Esmadent also sells a recycling machine (Esmadent Big Jane*) to enable orthodontists to recycle their own brackets. However, orthodontists working in the hospital service in the UK who wish to use the Esmadent should first check that it complies with British Standards. (Usiskin, 1992) McClea and Wallbridge (1986) demonstrated that reconditioning using the Esmadent Big Jane* was as effective as commercial recycling. In contrast, the recycling sequence used by the Orthocycle company is an example of the second method, using chemical solvents. They utilize a solvent stripping process together with high frequency vibrations at temperatures below•toooc to remove the composite. This is followed by heating to 250oc for sterilization and a very short 'flash' .• Esmadent, Division of Esma Chemicals, PO Box 162, H1ghland Park, Illinois, 600-35, USA. I!) 1992 British Society ror the Study or Orthodontics
158
K. M. Postlethwaite
electropolishing stage. The company states that 5I 0 microns of metal are removed. In addition to these procedures, many companies carry out an etching procedure on recycled nonmesh undercut integral bracket bases to enhance their retention. This procedure is not necessary for mesh based brackets. Since 1987, some companies have offered a recycling service for ceramic brackets. The procedures used to recycle ceramics are different from those used for stainless steel, but the exact methods have not been described (Lewy, 1991; Matasa, 1990). However, the techniques are based on using chemical solvents to strip off the adhesive. A silane primer is applied to the bases of those brackets without mechanical undercuts. There are many other commercial recycling companies in the United Kingdom and the United States but their exact methods have never been published. Effects of Recycling
The effects of recycling depend on the type of recycling process used, the type of steel from which the bracket or band is constructed, whether the bracket is milled or cast, and whether the bracket base is a mesh pad, or a non-mesh, undercut integral pad. Many studies have reported on and quantified the effects of recycling. (Buchman, 1980; Hixson et al., 1982; Mascia and Chen, 1982; Wheeler and Ackerman, 1982; Ferguson et al., 1984; Siomka and Powers, 1985; Wright and Powers, 1985; Me Clea and Wallbridge, 1986; Smith, 1986; Buchwald, 1989; Matasa, 1989; Regan et al., 1990) The most consistent finding is that recycling produces a reduction in bond strength which is clinically insignificant. However, with some types of bracket base and some types of recycling, bond strengths may increase. The recycling process may also produce a small alteration in bracket slot tolerance, physical distortion of the bracket and corrosion of the metal. The effects of recycling have been summarized by Matasa (1989). He classified the effects of recycling into those that were produced by the debonding procedure, those that were produced by the heat cycle, and those that were produced as a result of electropolishing, (see Table 1). It is worth considering some of the effects summarized by Matasa in more detail. Although clinical use of an appliance can lead to some minor deformation, the debonding step is responsible for most bracket distortion and damage, (Oliver and Pal, 1989; Matasa, 1989). A study of the mechanical impact of the different
BJO Vol. 19 No. 2
TABLE
I
Effects of debonding (i) slot closing (ii) base shape alteration (iii) under tie wing area closing (iv) tie wing gap (Siamese brackets) narrowing (v) power arm distortion Effects of heat recycling (i) steel corrosion (ii) structural metal weakening (iii) clogging of base mesh with debris (iv) vertical slot obstruction (v) blocking of mechanisms: SPEED® and ACTIV A® brackets Effects of metal removal due to electropolishing (i) slot enlargement (ii) wings sharpen (Power chain and 0 rings fail) (iii) base flattening: pitch of mesh is reduced (iv) dissolution of brazing or welding on bracket base (v) power arm thinning (vi) undercuts shaved e.g. Dynalok®. Seen most dramatically with sintered metal particle bases (SPEED)® where bond strength is severely reduced ®SPEED, Orec Corporation, San Clemente, CA. ®Activa, A Company, PO Box 81247, San Diego, CA. ®Dyna-Lock, Unitek Corp., Monrovia, CA.
methods of debonding on the integrity of the bracket and the best methods of debonding has been published (Matasa, 1988a). The electrothermal debracketing technique offers high yields of undamaged brackets (Matasa, 1988b). Buchman (1980) and Hixson et al. ( 1982) evaluated the change in slot and torque in brackets after recycling. Both studies found negligible changes. There is greater variability in archwirejslot fit produced by the variation in thickness of rectangular wires than that caused by the increased tolerance of the slot produced by recycling, (Hixson et al., 1982). Mascia and Chen ( 1982) and Wright and Powers ( 1985) found a decrease in bond strength using mesh based brackets following the Orthocycle and Esmadent processes. Wright and Powers suggested that the cause of the decrease in bond strength was a decrease in mesh wire diameter produced by the recycling process. Wheeler and Ackerman (1982) found a slight overall decrease in bond strength following recycling, although 43% of the brackets exhibited increased bond strength. In the same study it was found that the mesh wire diameter decreased in all brackets following recycling. Smith ( 1986) found no significant change in bond strength following recycling mesh brackets with Esmadent or Orthocycle following two successive recyclings, although the mesh wire diameter decreased signifi-
Recycling Bands and Brackets
BJO May /992
cantly with both processes. Smith ( 1986) also recycled Dynalok® brackets using the same companies. Interestingly, both recycling methods lead to an increase in bond strength for Dynalok® brackets. The increase in bond strength of Dynalok® brackets was explained by etching of the metal during the Orthocycle sequence, whereas Esmadent recycling led to rounding of the sharp edges on the undercut channels. These findings agree with Siomka and Powers ( 1985) and Ferguson et al. (1984). In contrast, Regan et al. (1990) found that there was a decrease in bond strength for all types of brackets used in their study (Dynalok®, machined integral base, Edgeway®, integral cast bracket-base combination, and Rocky Mountain®, conventional foil mesh base) following recycling with either Orthocycle or Esmadent. They also concluded that thermal recycling produced an unacceptably large reduction in the bond stength of the cast base and advised that this method should be avoided with cast brackets. Buchman ( 1980) studied the metallurgy of milled brackets before and after recycling, comparing the results of four recycling companies. The milled brackets showed small changes in microstructure and a decrease in hardness with most recycling processes. However, the clinical significance of these findings was not determined. Smith ( 1986), although not directly investigating metallurgical properties noticed that some cast brackets became distorted during tests for bond strength following recycling. Conversely, the milled brackets showed no distortion following recycling. Maejer and Smith (1986) compared the amount of corrosion produced in nine different types of brackets before recycyling by immersing them in a simulated oral environment using artificial saliva. They also determined the degree of corrosion produced following recycling by three different commercial companies. They demonstrated that before the recycling process, brackets exhibit corrosion to a variable degree and all three methods of recycling increased the liability of brackets to undergo corrosion. However, some bracket bases demonstrated more resistance to corrosion during recycling than others. Some studies have considered the effects of cumulative recycling. Regan et al. ( 1990) found that there was not a statistically significant reduction in bond strength when brackets were recycled up to five times. However, in the study by Buchwald (1989) where Microloc® brackets were recycled ®Oyna-Lock, Unitek Corp., Monrovia, CA; ®Edgeway, Orthodontic Organisers Inc., San Marcos, CA; ®Rocky Mountain, Rocky Mountain Orthodontics, Denver, CO. ®Microloc, GAC International, Central Islip, NY.
159
three times by Orthocyle, the percentage of appliances that could be reused diminished with each recycling process. Interestingly, of those brackets which could be reused, the frequency of bond failures was the same as for new appliances. Some orthodontists fear that use of recycled products may produce an increase in the risk of cross infection. However, any cross contamination due to the previous wear of a recycled appliance is not possible, since the recycling treatments to which they are subjected will effectively clean and decontaminate the appliances (Matasa, 1991). In addition to this, at least one recycling company is now sterilizing brackets after inspection and remarking, prior to packaging. Some authorities believe that when recycled products are used, the patients should be informed that this is the case, and, if they arc used in the private sector, the cost of treatment should be reduced (Zachrisson, 1985; Unkel, 1987). Survey In order to compare the services and prices of commercial recycling, a questionnaire was sent to the orthodontic supply companies in the UK, and to recycling companies in the UK and USA. The majority of orthodontic supply companies replied explaining that they did not offer recycling services because the manufacturers now safeguard their product liability clause by printing disclaimers on all products. The disclaimer usually states 'For single use only. The company and its agents will not be responsible for any or all claims resulting from multiple use of this product'. However, three orthodontic supply companies, Hudson Limited, Orthocare and Precision Orthodontics do offer a recycling service, in addition to the established recycling companies in the UK and USA. Orthocare carries out its own recycling service on the premises. Hudson Limited acts as an agent for one of the large recycling companies. Precision Orthodontics acts as an agent on behalf of several recycling companies and offers a comprehensive range of services including some services out to its own specification. Results from questionnaire Some companies completed and returned the questionnaire as requested, enclosing relevant product literature and prices. Information on the remaining companies was obtained by a telephone interview using the same questions as the ones used in the questionnaire. The main findings are summarized in Table 2.
2
Price varies with no. brackets yes Cost per steel band 30 ~ Cost per ceramic bracket N/A
16-25 ~
yes yes no
Esmadent USA
yes NfA NfA
yes
yes no no 10-15 p
N/A N/A
yes no no 29-38 p
95 40~
304: 40~
1.15
'special' service 35 ~ yes
'quality' service 20-30 4: yes ~-s
yes yes yes 'standard' service 10-28 ~
yes yes yes 'economy' service 10-15 ~ 'ideal' service 20-28 4: yes 22-95 4: 12-32 ~
yes yes yes 'thrifty' service 10-14 ~
N/A 15 p
no
yes no yes 15 p
yes 80-85 p 20p
-20p
yes yes yes
16-25
yes yes yes ~
Vector USA
N/A
304:
serviceB ll-13 p serviceC 9-lOp yes yes 30 4:-S 1.35 N/A
yes no no service A 13-15 p
Orthodontic reconditioning Orthocare Precision Sussex Hudson limited Orthocycle Orthotronics company Orthonor orthodontics Re bond USA USA UK UK USA UK UK UK
Comparison of seroice and price for recycling brackets and bands
Steel brackets recycled Steel bands recycled Ceramic brackets recycled Cost per steel bracket
TABLE
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Recycling Bands and Brackets
BJO May 1991
161
Steel brackets
Sorting service for bands
• All companies recycle all types of steel brackets. • The cost of recycling steel brackets varies from 10-35 ~(USA) and 9-20 p (UK). • The difference in price between companies depends on two main factors. Firstly, the method of reducing price for bulk orders varies between companies. Secondly, the degree of sophistication of sorting, quality control and the availability of a 'remarking' service all affect the price. Some companies offer different 'grades' of recycling service and each grade receives a different price band e.g. Orthocycle (USA), Orthotronics (USA), Orthodontic Reconditioning Company (USA), Sussex Rebond (UK), Vector (USA).
• Most companies do not offer a sorting service for bands. The Orthodontic Reconditioning Company (USA), Orthotronics (USA), Precision Orthodontics (UK) and Vector (USA) do offer a sorting service for bands. • The cost of sorting bands from Orthotronics is included in the price of recycling bands (95 ~-S 1.15) and includes resize and remarking. The cost of sorting bands from the Orthodontic Reconditioning Company is included in the price of the 'ideal' service varying from 70-95 ~each, depending on the total number sent and including resizing and remarking. At Vector, unsorted recycled bands cost 30 ~ each; sorted bands cost S1.35 each and they are also resized and remarked for that price. The cost of sorting bands from Precision Orthodontics is included in the price of recycling bands (80-85 p) although this price does not include resizing or remarking.
Steel bands
• All companies except Hudson Limited (UK), Orthocare (UK), Orthonor (UK) and Sussex Rebond (UK) recycle steel bands. • The cost of recycling steel bands varies from 22 ~ S 1.35 (USA) and 80-85 p (UK). • The difference in price between companies depends on the same factors as those cited above for brackets. Ceramic brackets
• All companies except Esmadent (USA), Hudson Limited (UK), Orthocare (UK) and Sussex Rebond (UK) recycle ceramic brackets. • The cost of recycling ceramic brackets varies from 12-40 HUSA) and 15-20 p (UK).
Methods of quality control
• All the companies stated that they operate mechanisms of quality control, although many did not specify the methods used to ensure it. • All companies check brackets before recycling and return damaged brackets of the sender at no cost. • Several companies offered different levels of quality control depending on the type of service specified by the customer (see Table 2 for detailed information). Other services
Sorting service for brackets
• All companies except Esmadent (USA) offer a sorting service for brackets, although the degree of sophistication of sorting varies greatly between companies and the small print of company brochures needs to be read carefully. • Orthocare (UK) and Precision Orthodontics (UK) offer a sorting service only for certain types of brackets (see Table 2 for detailed information). • Most companies charge extra for a sorting service. The extra charge for sorting varies from 5-30 ~(USA) and from 8-20 p (UK). Differences in the price reflect the degree of sophistication of sorting. Many companies offer different grades of sorting at different prices, for example, Orthocycle, Orthotronics, Vector and Sussex Re bond (see Table 2 for detailed information).
In addition to the standard recycling operations considered in this paper, some companies offer other related services. • Buying used bands and brackets to recycle and sell to other customers. • Selling recycled products. • Recycling other orthodontic materials e.g. nickel titanium arch wires, face bows, Herbst appliances, expansion devices. • Removal of tube assemblies from old bands, recycling them and rewelding them to new bands. Summary
Orthodl..)ntists have a wide choice of companies offering a comprehensive recycling service at competitive prices. Careful debonding procedures
no
N/A
Sorting service for bands
Cost of sorting bands
Quality control yes
N/A
Cost of sorting brackets
Esmadent USA yes sortingonly for brackets sold by Orthocare
Orthocare limited UK
yes
N/A
no
Orthotronics USA
N/A
yes microscopic check & slot check
yes
no
no extra charge over 'quality' service price. 5 t extra on quality service for remarking bracket
yes in 'special' service; not in 'standard' service
no extra cost
yes includes sort resize & mark
extra 5 ~ each
yes yes ('quality' service includes sort; no sort in 'economy' service)
Orthocycle USA
N/A
no
extra 8-10 included in price of p each recycling bracket
yes
Hudson UK
Comparison of sorting sen•ice and price for brackets and bands
no
3
Sorting service for brackets
TABLE
Orthonor UK
yes in 'ideal' service; not in 'thrifty' service
yes ('ideal' service includes sort resize & mark) no extra cost with 'ideal' service
yes (service A includes sort; service B & C no sort
yes sortingonly for 'A' company& Ortho Organizers brackets std size: extra 12 p minitwin: extra 20 p each
N/A
no extra cost
S 1.35 includes sort resize & mark (30 t-no sort sizing or mark)
yes includes sort resize & mark
'standard sort: extra 18 ~ each 'complete' sort: extra
yes 2 grades of sort: 'standard' & 'complete'
Vector USA
yes yes in service A & B; not in C
no
yes
no extra charge over service A price 30 ~ each
Sussex Re bond UK
Precision orthodontics UK
yes yes visual exam under magnification slot check
N/A
no
no extra charge included in over 'ideal' price of service price recycling includes remarking
yes yes ('ideal' service (limited) includes sort; no sort in 'thrifty' service)
Orthodontic reconditioning company USA
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ISSN: 0301-228X (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/yjor19
Recycling Bands and Brackets K. M. Postlethwaite B.D.S., M.Sc., M.Orth., R.C.S., F.D.S., R.C.P.S. To cite this article: K. M. Postlethwaite B.D.S., M.Sc., M.Orth., R.C.S., F.D.S., R.C.P.S. (1992) Recycling Bands and Brackets, British Journal of Orthodontics, 19:2, 157-164, DOI: 10.1179/ bjo.19.2.157 To link to this article: http://dx.doi.org/10.1179/bjo.19.2.157
Published online: 21 Jun 2016.
Submit your article to this journal
View related articles
Citing articles: 9 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=yjor19 Download by: [Tufts University]
Date: 22 November 2016, At: 08:56
British Journal of Orthodontics/Vol. 19/1992/157-164
Orthodontic Materials Update Recycling Bands and Brackets K. M. PosTLETHW AITE, B.D.S., M.Sc., M.ORTH., R.C.S., F.D.S., R.C.P.S. ?rth?donti~ Department, Floor 22, Guys Tower, London SE19RTand Dental & Maxillofacial Department Hospital tor Sick Children, Great Ormond Street, London WClN 3JH '
Introduction
Following the advent of direct bonding during the 1970s, techniques evolved for recycling brackets so that they could be reused, thereby reducing the cost per case. During the 1980s, the number of brackets being recycled increased, with many recycling companies becoming well established in the United States and the United Kingdom. Now, during the early 1990s, 75% of American orthodontists are recycling some of their bands and b~a~kets (Lewy, 1991 ). Even though recycling has d1stmct economic advantages, many orthodontists continue to have reservations about it. Firstly, almost all of the orthodontic manufacturers state that their products are for single use only, and print a disclaiming notice which is attached to their products, stating that no liability will be borne by the company if their products are reused. Secondly, there are concerns about the possible increased risk of cross infection if recycled products are used (Unkel, 1987). Thirdly, orthodontists seek reassurance that the quality of the recycled product is satisfactory, with a clinical performance similar to the new product and with equally low rates of bond failure. Finally, there are fears that litigation could result from the use of recycled products if it could be proved that failure of an appliance, substandard orthodontic treatment or cross infection was attributable to use of a recycled product. In this paper, the methods and effects of recycling are reviewed, and the services and prices of several companies in the United Kingdom and the United States are compared. Methods of recycling
The aim of any recycling system is to completely remove adhesive from the bracket without causing damage to the bracket base, so that the bracket can be rebonded to enamel producing a new adhesive 030 1-228X/92/002000 + 00102.00
bond of adequate strength. There are two main methods of recycling in use: (1) Application of heat to burn off the adhesive and (2) Use of chemical solvents to strip off the adhesive (Zachrisson, 1985).
A? ex_amp~e of the first method, relying on heat application, IS the recycling process used by the Esmadentcompany, whilstanexampleofthesecond method using chemical solvents is the process used by Orthocycle. Both of these methods have been investigated fully. (Buchman, 1980; Hixson et al., 1982; Mascia and Chen, 1982; Smith, 1986; Regan et al., 1990) With the Esmadent system, the brackets are heated to 454°C for 45 minutes. Following this, the hot brackets are immersed into a cold cement solvent and ultrasonically cleaned for 10-15 minutes. The brackets are then washed, dried and electropolished for 30-45 seconds. Brackets are then placed in sodium bicarbonate solution to neutralize the electrolyte, followed by hot water rinsing. 50 microns of metal are removed by this method. Esmadent also sells a recycling machine (Esmadent Big Jane*) to enable orthodontists to recycle their own brackets. However, orthodontists working in the hospital service in the UK who wish to use the Esmadent should first check that it complies with British Standards. (Usiskin, 1992) McClea and Wallbridge (1986) demonstrated that reconditioning using the Esmadent Big Jane* was as effective as commercial recycling. In contrast, the recycling sequence used by the Orthocycle company is an example of the second method, using chemical solvents. They utilize a solvent stripping process together with high frequency vibrations at temperatures below•toooc to remove the composite. This is followed by heating to 250oc for sterilization and a very short 'flash' .• Esmadent, Division of Esma Chemicals, PO Box 162, H1ghland Park, Illinois, 600-35, USA. I!) 1992 British Society ror the Study or Orthodontics
158
K. M. Postlethwaite
electropolishing stage. The company states that 5I 0 microns of metal are removed. In addition to these procedures, many companies carry out an etching procedure on recycled nonmesh undercut integral bracket bases to enhance their retention. This procedure is not necessary for mesh based brackets. Since 1987, some companies have offered a recycling service for ceramic brackets. The procedures used to recycle ceramics are different from those used for stainless steel, but the exact methods have not been described (Lewy, 1991; Matasa, 1990). However, the techniques are based on using chemical solvents to strip off the adhesive. A silane primer is applied to the bases of those brackets without mechanical undercuts. There are many other commercial recycling companies in the United Kingdom and the United States but their exact methods have never been published. Effects of Recycling
The effects of recycling depend on the type of recycling process used, the type of steel from which the bracket or band is constructed, whether the bracket is milled or cast, and whether the bracket base is a mesh pad, or a non-mesh, undercut integral pad. Many studies have reported on and quantified the effects of recycling. (Buchman, 1980; Hixson et al., 1982; Mascia and Chen, 1982; Wheeler and Ackerman, 1982; Ferguson et al., 1984; Siomka and Powers, 1985; Wright and Powers, 1985; Me Clea and Wallbridge, 1986; Smith, 1986; Buchwald, 1989; Matasa, 1989; Regan et al., 1990) The most consistent finding is that recycling produces a reduction in bond strength which is clinically insignificant. However, with some types of bracket base and some types of recycling, bond strengths may increase. The recycling process may also produce a small alteration in bracket slot tolerance, physical distortion of the bracket and corrosion of the metal. The effects of recycling have been summarized by Matasa (1989). He classified the effects of recycling into those that were produced by the debonding procedure, those that were produced by the heat cycle, and those that were produced as a result of electropolishing, (see Table 1). It is worth considering some of the effects summarized by Matasa in more detail. Although clinical use of an appliance can lead to some minor deformation, the debonding step is responsible for most bracket distortion and damage, (Oliver and Pal, 1989; Matasa, 1989). A study of the mechanical impact of the different
BJO Vol. 19 No. 2
TABLE
I
Effects of debonding (i) slot closing (ii) base shape alteration (iii) under tie wing area closing (iv) tie wing gap (Siamese brackets) narrowing (v) power arm distortion Effects of heat recycling (i) steel corrosion (ii) structural metal weakening (iii) clogging of base mesh with debris (iv) vertical slot obstruction (v) blocking of mechanisms: SPEED® and ACTIV A® brackets Effects of metal removal due to electropolishing (i) slot enlargement (ii) wings sharpen (Power chain and 0 rings fail) (iii) base flattening: pitch of mesh is reduced (iv) dissolution of brazing or welding on bracket base (v) power arm thinning (vi) undercuts shaved e.g. Dynalok®. Seen most dramatically with sintered metal particle bases (SPEED)® where bond strength is severely reduced ®SPEED, Orec Corporation, San Clemente, CA. ®Activa, A Company, PO Box 81247, San Diego, CA. ®Dyna-Lock, Unitek Corp., Monrovia, CA.
methods of debonding on the integrity of the bracket and the best methods of debonding has been published (Matasa, 1988a). The electrothermal debracketing technique offers high yields of undamaged brackets (Matasa, 1988b). Buchman (1980) and Hixson et al. ( 1982) evaluated the change in slot and torque in brackets after recycling. Both studies found negligible changes. There is greater variability in archwirejslot fit produced by the variation in thickness of rectangular wires than that caused by the increased tolerance of the slot produced by recycling, (Hixson et al., 1982). Mascia and Chen ( 1982) and Wright and Powers ( 1985) found a decrease in bond strength using mesh based brackets following the Orthocycle and Esmadent processes. Wright and Powers suggested that the cause of the decrease in bond strength was a decrease in mesh wire diameter produced by the recycling process. Wheeler and Ackerman (1982) found a slight overall decrease in bond strength following recycling, although 43% of the brackets exhibited increased bond strength. In the same study it was found that the mesh wire diameter decreased in all brackets following recycling. Smith ( 1986) found no significant change in bond strength following recycling mesh brackets with Esmadent or Orthocycle following two successive recyclings, although the mesh wire diameter decreased signifi-
Recycling Bands and Brackets
BJO May /992
cantly with both processes. Smith ( 1986) also recycled Dynalok® brackets using the same companies. Interestingly, both recycling methods lead to an increase in bond strength for Dynalok® brackets. The increase in bond strength of Dynalok® brackets was explained by etching of the metal during the Orthocycle sequence, whereas Esmadent recycling led to rounding of the sharp edges on the undercut channels. These findings agree with Siomka and Powers ( 1985) and Ferguson et al. (1984). In contrast, Regan et al. (1990) found that there was a decrease in bond strength for all types of brackets used in their study (Dynalok®, machined integral base, Edgeway®, integral cast bracket-base combination, and Rocky Mountain®, conventional foil mesh base) following recycling with either Orthocycle or Esmadent. They also concluded that thermal recycling produced an unacceptably large reduction in the bond stength of the cast base and advised that this method should be avoided with cast brackets. Buchman ( 1980) studied the metallurgy of milled brackets before and after recycling, comparing the results of four recycling companies. The milled brackets showed small changes in microstructure and a decrease in hardness with most recycling processes. However, the clinical significance of these findings was not determined. Smith ( 1986), although not directly investigating metallurgical properties noticed that some cast brackets became distorted during tests for bond strength following recycling. Conversely, the milled brackets showed no distortion following recycling. Maejer and Smith (1986) compared the amount of corrosion produced in nine different types of brackets before recycyling by immersing them in a simulated oral environment using artificial saliva. They also determined the degree of corrosion produced following recycling by three different commercial companies. They demonstrated that before the recycling process, brackets exhibit corrosion to a variable degree and all three methods of recycling increased the liability of brackets to undergo corrosion. However, some bracket bases demonstrated more resistance to corrosion during recycling than others. Some studies have considered the effects of cumulative recycling. Regan et al. ( 1990) found that there was not a statistically significant reduction in bond strength when brackets were recycled up to five times. However, in the study by Buchwald (1989) where Microloc® brackets were recycled ®Oyna-Lock, Unitek Corp., Monrovia, CA; ®Edgeway, Orthodontic Organisers Inc., San Marcos, CA; ®Rocky Mountain, Rocky Mountain Orthodontics, Denver, CO. ®Microloc, GAC International, Central Islip, NY.
159
three times by Orthocyle, the percentage of appliances that could be reused diminished with each recycling process. Interestingly, of those brackets which could be reused, the frequency of bond failures was the same as for new appliances. Some orthodontists fear that use of recycled products may produce an increase in the risk of cross infection. However, any cross contamination due to the previous wear of a recycled appliance is not possible, since the recycling treatments to which they are subjected will effectively clean and decontaminate the appliances (Matasa, 1991). In addition to this, at least one recycling company is now sterilizing brackets after inspection and remarking, prior to packaging. Some authorities believe that when recycled products are used, the patients should be informed that this is the case, and, if they arc used in the private sector, the cost of treatment should be reduced (Zachrisson, 1985; Unkel, 1987). Survey In order to compare the services and prices of commercial recycling, a questionnaire was sent to the orthodontic supply companies in the UK, and to recycling companies in the UK and USA. The majority of orthodontic supply companies replied explaining that they did not offer recycling services because the manufacturers now safeguard their product liability clause by printing disclaimers on all products. The disclaimer usually states 'For single use only. The company and its agents will not be responsible for any or all claims resulting from multiple use of this product'. However, three orthodontic supply companies, Hudson Limited, Orthocare and Precision Orthodontics do offer a recycling service, in addition to the established recycling companies in the UK and USA. Orthocare carries out its own recycling service on the premises. Hudson Limited acts as an agent for one of the large recycling companies. Precision Orthodontics acts as an agent on behalf of several recycling companies and offers a comprehensive range of services including some services out to its own specification. Results from questionnaire Some companies completed and returned the questionnaire as requested, enclosing relevant product literature and prices. Information on the remaining companies was obtained by a telephone interview using the same questions as the ones used in the questionnaire. The main findings are summarized in Table 2.
2
Price varies with no. brackets yes Cost per steel band 30 ~ Cost per ceramic bracket N/A
16-25 ~
yes yes no
Esmadent USA
yes NfA NfA
yes
yes no no 10-15 p
N/A N/A
yes no no 29-38 p
95 40~
304: 40~
1.15
'special' service 35 ~ yes
'quality' service 20-30 4: yes ~-s
yes yes yes 'standard' service 10-28 ~
yes yes yes 'economy' service 10-15 ~ 'ideal' service 20-28 4: yes 22-95 4: 12-32 ~
yes yes yes 'thrifty' service 10-14 ~
N/A 15 p
no
yes no yes 15 p
yes 80-85 p 20p
-20p
yes yes yes
16-25
yes yes yes ~
Vector USA
N/A
304:
serviceB ll-13 p serviceC 9-lOp yes yes 30 4:-S 1.35 N/A
yes no no service A 13-15 p
Orthodontic reconditioning Orthocare Precision Sussex Hudson limited Orthocycle Orthotronics company Orthonor orthodontics Re bond USA USA UK UK USA UK UK UK
Comparison of seroice and price for recycling brackets and bands
Steel brackets recycled Steel bands recycled Ceramic brackets recycled Cost per steel bracket
TABLE
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Recycling Bands and Brackets
BJO May 1991
161
Steel brackets
Sorting service for bands
• All companies recycle all types of steel brackets. • The cost of recycling steel brackets varies from 10-35 ~(USA) and 9-20 p (UK). • The difference in price between companies depends on two main factors. Firstly, the method of reducing price for bulk orders varies between companies. Secondly, the degree of sophistication of sorting, quality control and the availability of a 'remarking' service all affect the price. Some companies offer different 'grades' of recycling service and each grade receives a different price band e.g. Orthocycle (USA), Orthotronics (USA), Orthodontic Reconditioning Company (USA), Sussex Rebond (UK), Vector (USA).
• Most companies do not offer a sorting service for bands. The Orthodontic Reconditioning Company (USA), Orthotronics (USA), Precision Orthodontics (UK) and Vector (USA) do offer a sorting service for bands. • The cost of sorting bands from Orthotronics is included in the price of recycling bands (95 ~-S 1.15) and includes resize and remarking. The cost of sorting bands from the Orthodontic Reconditioning Company is included in the price of the 'ideal' service varying from 70-95 ~each, depending on the total number sent and including resizing and remarking. At Vector, unsorted recycled bands cost 30 ~ each; sorted bands cost S1.35 each and they are also resized and remarked for that price. The cost of sorting bands from Precision Orthodontics is included in the price of recycling bands (80-85 p) although this price does not include resizing or remarking.
Steel bands
• All companies except Hudson Limited (UK), Orthocare (UK), Orthonor (UK) and Sussex Rebond (UK) recycle steel bands. • The cost of recycling steel bands varies from 22 ~ S 1.35 (USA) and 80-85 p (UK). • The difference in price between companies depends on the same factors as those cited above for brackets. Ceramic brackets
• All companies except Esmadent (USA), Hudson Limited (UK), Orthocare (UK) and Sussex Rebond (UK) recycle ceramic brackets. • The cost of recycling ceramic brackets varies from 12-40 HUSA) and 15-20 p (UK).
Methods of quality control
• All the companies stated that they operate mechanisms of quality control, although many did not specify the methods used to ensure it. • All companies check brackets before recycling and return damaged brackets of the sender at no cost. • Several companies offered different levels of quality control depending on the type of service specified by the customer (see Table 2 for detailed information). Other services
Sorting service for brackets
• All companies except Esmadent (USA) offer a sorting service for brackets, although the degree of sophistication of sorting varies greatly between companies and the small print of company brochures needs to be read carefully. • Orthocare (UK) and Precision Orthodontics (UK) offer a sorting service only for certain types of brackets (see Table 2 for detailed information). • Most companies charge extra for a sorting service. The extra charge for sorting varies from 5-30 ~(USA) and from 8-20 p (UK). Differences in the price reflect the degree of sophistication of sorting. Many companies offer different grades of sorting at different prices, for example, Orthocycle, Orthotronics, Vector and Sussex Re bond (see Table 2 for detailed information).
In addition to the standard recycling operations considered in this paper, some companies offer other related services. • Buying used bands and brackets to recycle and sell to other customers. • Selling recycled products. • Recycling other orthodontic materials e.g. nickel titanium arch wires, face bows, Herbst appliances, expansion devices. • Removal of tube assemblies from old bands, recycling them and rewelding them to new bands. Summary
Orthodl..)ntists have a wide choice of companies offering a comprehensive recycling service at competitive prices. Careful debonding procedures
no
N/A
Sorting service for bands
Cost of sorting bands
Quality control yes
N/A
Cost of sorting brackets
Esmadent USA yes sortingonly for brackets sold by Orthocare
Orthocare limited UK
yes
N/A
no
Orthotronics USA
N/A
yes microscopic check & slot check
yes
no
no extra charge over 'quality' service price. 5 t extra on quality service for remarking bracket
yes in 'special' service; not in 'standard' service
no extra cost
yes includes sort resize & mark
extra 5 ~ each
yes yes ('quality' service includes sort; no sort in 'economy' service)
Orthocycle USA
N/A
no
extra 8-10 included in price of p each recycling bracket
yes
Hudson UK
Comparison of sorting sen•ice and price for brackets and bands
no
3
Sorting service for brackets
TABLE
Orthonor UK
yes in 'ideal' service; not in 'thrifty' service
yes ('ideal' service includes sort resize & mark) no extra cost with 'ideal' service
yes (service A includes sort; service B & C no sort
yes sortingonly for 'A' company& Ortho Organizers brackets std size: extra 12 p minitwin: extra 20 p each
N/A
no extra cost
S 1.35 includes sort resize & mark (30 t-no sort sizing or mark)
yes includes sort resize & mark
'standard sort: extra 18 ~ each 'complete' sort: extra
yes 2 grades of sort: 'standard' & 'complete'
Vector USA
yes yes in service A & B; not in C
no
yes
no extra charge over service A price 30 ~ each
Sussex Re bond UK
Precision orthodontics UK
yes yes visual exam under magnification slot check
N/A
no
no extra charge included in over 'ideal' price of service price recycling includes remarking
yes yes ('ideal' service (limited) includes sort; no sort in 'thrifty' service)
Orthodontic reconditioning company USA
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