Schwermetallfreisetzungsprofile aus kieferorthopädischen Bändern Brackets und Drähten: Eine In-vitro-Untersuchung

Abstract

AimThe present study evaluated the temporal release of Co Cr, Mn, and Ni from the components of a typical orthodontic appliance during simulated orthodontic treatment.Materials and methodsSeveral commercially available types of bands, brackets, and wires were exposed to an artificial saliva solution for at least 44 days and the metals released were quantified in regular intervals using inductively coupled plasma quadrupole mass spectrometry (ICP-MS, Elan DRC+, Perkin Elmer, USA). Corrosion products encountered on some products were investigated by a scanning electron microscope equipped with an energy dispersive X-ray microanalyzer (EDX).ResultsBands released the largest quantities of Co, Cr, Mn, and Ni, followed by brackets and wires. Three different temporal metal release profiles were observed: (1) constant, though not necessarily linear release, (2) saturation (metal release stopped after a certain time), and (3) an intermediate release profile that showed signs of saturation without reaching saturation. These temporal metal liberation profiles were found to be strongly dependent on the individual test pieces. The corrosion products which developed on some of the bands after a 6-month immersion in artificial saliva and the different metal release profiles of the investigated bands were traced back to different attachments welded onto the bands.ConclusionThe use of constant release rates will clearly underestimate metal intake by the patient during the first couple of days and overestimate exposure during the remainder of the treatment which is usually several months long. While our data are consistent with heavy metal release by orthodontic materials at levels well below typical dietary intake, we nevertheless recommend the use of titanium brackets and replacement of the band with a tube in cases of severe Ni or Cr allergy.

Are Metal Ions That Make up Orthodontic Alloys Cytotoxic, and Do They Induce Oxidative Stress in a Yeast Cell Model?

“…Each part of an orthodontic appliance, whether an archwire, bracket or band, may differ from other parts by their composition and characteristics [1]. To make a fixed orthodontic appliance, some parts have to be joined together, whether that be by brazing, soldering or welding [2].…”

In Vitro Ion Release of Wires in Removable Orthodontic Appliances

“…In addition to the total ion output, an evaluation of the daily output from the appliance is useful. According to Wendl, concentration decreases after the first few days of the appliance’s insertion and approaches saturation depending on the alloy [ 16 ]. The resin Orthocryl ® used in this experiment has already been classified as slightly toxic to fibroblasts in in vitro tests [ 19 ].…”

“…Aluminium is also under suspicion for causing neurodegenerative diseases, e.g., Alzheimer [ 15 ]. Although the concentration of dissolved ions from fixed appliances seems to decrease either constantly or even stops due to saturation [ 16 ], the release of critical elements in removable appliances should also be investigated. Thus, the aim of this study was to detect metal ions (aluminium, chromium, nickel) released from the wires into a corrosive solution during simulated daily usage.…”

Comparison of Cell Viability and Chemical Composition of Six Latest Generation Orthodontic Wires

“…The oral cavity has chemical and microbiological conditions conducive to the release of metal ions from alloys and coatings [ 2 ]. These conditions include the alkaline properties of saliva, electrolytes formed by food debris, variations in pH, mechanical action, and microbial flora [ 3 ]. Some of these released metallic elements can modulate the immune response causing inflammation [ 4 ], allergic and systemic reactions [ 5 ], and hypersensitivity [ 6 ].…”