6. Remedy
_____The allergic potential of orthodontic appliances has been considered as overestimated (probably less than 0.2% of patients suffering allergic skin reactions during their orthodontic therapy).1 Understandably, relatively few reports had dealt openly with the problem.2,3 Even so, the clinician should be able to provide a preliminary cure and take all the necessary measures without limiting himself to remove the cause hoping that the effects will cease to exist.
_____Rational approaches in management of an allergic response to an offensive device/biomaterial appear to be: (1) attachment’s removal, (2) substitution with a less offensive device/material, (3) symptomatic therapy and (4) administration of medicines with immobilization left in place.
_____The intuitive approach of removing/substituting the offending device/ biomaterial is not as easy as it may seem, as otherwise it should have first taken place. The most suggested replacements are titanium and coated appliances that can be wires, brackets, tubes, mini-screws, etc.4-10 Of course, due to galvanism, metal coatings, soldering and brazing should be avoided.1 Interestingly, titanium nitride coatings are not recommended for the improvement of deficient dental alloys11 , nor for improving the corrosion resistance of stainless steel brackets.12
_____Treatment. An addition to the removal/replacement concept is a concomitant antioxidant therapy that is reported to alleviate symptoms and improve quality of life in patients.13 Other studies advocate a treatment with oral antihistamines and topical corticosteroids.14, 15
_____In severe cases of metal intoxication, chelating therapy could be also applied: used successfully since over a century in other fields, the binding of transition elements in view of their removal has been used in nickel eczema and dermatitis. Favorable response has been obtained by placing patients on a diet of low nickel content together with the oral administration of sodium diethyldithiocarbamate (Dithiocarb) or tetraethyl-thiuram.16, 17 Chelation therapy has given good results in removing also other transition elements such as Cr, Mn and Cd.18, 19
_____EDTA (ethylenediamine tetra-acetic acid) chelation is a widespread therapy by which repeated administrations of this weak synthetic amino acid gradually reduce atherosclerotic plaque and other mineral/metal deposits throughout the cardiovascular system. The accrual of these toxins invites an increased risk for various diseases. Administered by I.V. therapy for half a century against metal poisoning, EDTA has a direct and powerful effect on the body almost instantaneously. A session usually lasts about 3 to 4 hours, during which about 1500 mg to 3000 mg of EDTA (plus vitamin C and other nutrients) are administered. The number of treatments necessary (generally about 20-50 sessions) depends on the individual’s condition. Interestingly, EDTA can be administered also orally, in which case only about 5% to 10% of an oral dose of EDTA is absorbed, a fact that results in the necessity of far higher doses.
_____Observing a decrease in corrosion, other agents were also tried, among which fatty amides by Armour, a quaternary ammonium salt (Maquat, by Mason Chemicals, Chicago), thiourea, again benzotriazole and EDTA. Even without any sealant to protect the complexes formed with the active sites of the metal surface, the attachments thus treated maintained part of the protection achieved even after tumbling for hours with a suspension of corn seeds in water.
_____Interesting not only as a band-aid approach to remediation, the metal attachment’s surface sequestration followed by sealing holds promises and is worth further investigations.
_____References
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