Article

Comparison of metal release from new and recycled bracket-archwire combinations.

Department of Orthodontics, Başkent University Faculty of Dentistry, Ankara, Turkey.
The Angle Orthodontist (impact factor: 1.21). 02/2005; 75(1):92-4. DOI:10.1043/0003-3219(2005)075<0092:COMRFN>2.0.CO;2 pp.92-4
Source: PubMed

ABSTRACT Most orthodontic brackets and archwires made from stainless steel or nickel (Ni)-titanium (Ti) alloys can release metal ions into the saliva. This study measures the amounts of metal released from simulated fixed orthodontic appliances. Sixty simulated fixed orthodontic appliances were manufactured in different ways and divided into four equal groups as follows: new brackets and new archwires (group 1 controls), new brackets and recycled archwires (group 2), recycled brackets and new archwires (group 3), and recycled brackets and recycled archwires (group 4). The bracket bases coated with adhesives were heated at 350 degrees C for 30 minutes. Recycled archwires were sterilized by autoclaving. Each appliance was soaked in artificial saliva of pH 7 at 37 degrees C for 45 days. At the end of this period, a sample of the artificial saliva was collected for analysis. Concentrations of Ni, chromium (Cr), iron (Fe), manganese, copper (Cu), and Ti ions were measured by atomic absorption and recorded in micrograms per liter. Analysis of variance and the Duncan multiple-range test indicated significant differences among the groups (P < .001). The study revealed the following: (1) group 4 released higher amounts of Cr, Fe, and Ti than any of the other three combinations; (2) Ni release was similar in groups 1 and 2 and in groups 2, 3, and 4; (3) the amounts of Cu, Cr, and Ti ions released from groups 3 and 4 were significantly greater than the amounts released from the other two combinations.

0 0
 · 
0 Bookmarks
 · 
20 Views
  • Source
    Article: Release of metal ions from orthodontic appliances: an in vitro study.
    Marcin Mikulewicz, Katarzyna Chojnacka, Barbara Woźniak, Patrycja Downarowicz
    [show abstract] [hide abstract]
    ABSTRACT: In this paper, we report the results of an in vitro experiment on the release of metal ions from orthodontic appliances composed of alloys containing iron, chromium, nickel, silicon, and molybdenum into artificial saliva. The concentrations of magnesium, aluminum, silicon, phosphorus, sulfur, potassium, calcium, titanium, vanadium, manganese, iron, cobalt, copper, zinc, nickel, and chromium were significantly higher in artificial saliva in which metal brackets, bands, and wires used in orthodontics were incubated. In relation to the maximum acceptable concentrations of metal ions in drinking water and to recommended daily doses, two elements of concern were nickel (573 vs. 15 μg/l in the controls) and chromium (101 vs. 8 μg/l in the controls). Three ion release coefficients were defined: α, a dimensionless multiplication factor; β, the difference in concentrations (in micrograms per liter); and γ, the ion release coefficient (in percent). The elevated levels of metals in saliva are thought to occur by corrosion of the chemical elements in the alloys or welding materials. The concentrations of some groups of dissolved elements appear to be interrelated.
    Biological trace element research 10/2011; 146(2):272-80. · 1.92 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

artificial saliva
 
atomic absorption
 
bracket bases
 
Duncan multiple-range test
 
equal groups
 
group 1 controls
 
group 4
 
groups 1
 
micrograms
 
new archwires
 
new brackets
 
nickel
 
orthodontic appliances
 
orthodontic brackets
 
recycled archwires
 
recycled brackets
 
stainless steel
 
three combinations
 
Ti ions
 
two combinations
 

Seda Gürsoy