The frictional characteristics of two types of zirconia (Harmony, Hudson Ltd., Sheffield, U.K., and Toray, Yamaura Corp., Tokyo, Japan) brackets were compared with those of polycrystalline alumina (Transcend 2000, Unitek Corp., Monrovia, Calif.) brackets in both dry and wet states. To compare the couples, four arch wire alloys were studied: stainless steel, cobalt-chromium, nickel titanium, and beta-titanium. Under dry conditions, the highest frictional coefficients were seen with the Harmony/beta-titanium couple (uk = 0.64); the lowest values were seen with both Transcend 2000/stainless steel (uk = 0.13) and Toray/cobalt-chromium couples (uk = 0.13). Beta-titanium arch wires produced the highest coefficients of friction against each type of ceramic bracket, except against Toray arch wires in the wet state. The presence of human saliva produced only slight changes in the frictional behavior of zirconia brackets. We conclude that currently available zirconia brackets offer no significant improvement over alumina brackets with regard to their frictional characteristics.
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http://dx.doi.org/10.1016/S0889-5406(94)70085-0 | DOI Listing |
BMC Oral Health
December 2024
Faculty of Dentistry, Innovative Dental Materials and Interfaces Research Unit (URB2i), UR 4462, Paris Cité University, 1 rue Maurice Arnoux, Montrouge, 92120, France.
Objective: To evaluate the shear bond strength (SBS) and adhesive remnant index (ARI) scores of metal brackets to glazed lithium disilicate reinforced glass-ceramics and zirconia according to various surface treatment protocols.
Methods: A total of 240 lithium disilicate ceramic (LD) and 240 zirconia (Zr) blocks were randomly divided according to sandblasting, hydrofluoric acid (HF) etching, universal primer use, and the adhesive system applied. A maxillary canine metal bracket was bonded to each sample with resin cement (Transbond XT, TXT).
Angew Chem Int Ed Engl
December 2024
Department of chemistry, University of California, Riverside, Riverside, CA, 92521, USA.
Sulfated zirconium oxide (SZO) catalyzes the hydrogenolysis of isotactic polypropylene (iPP, M=13.3 kDa, Đ=2.4,
Eur Oral Res
September 2024
Faculty of Medicine and Dentistry, Palacký University, 775 15 Olomouc, Czech Republic.
Purpose: Adhesive remnants removal is the last key step influencing orthodontic treatment outcomes. Four different clearance methods (CM) of orthodontic adhesive were evaluated to determine, which achieved the smoothest enamel surface in the shortest time.
Materials And Methods: 75 intact premolars extracted for orthodontic purposes were included, sixty had an orthodontic bracket bonded and subsequently removed, and fifteen served as the control group.
J Contemp Dent Pract
July 2024
Department of Oral Pathology, SRM Dental College, Chennai, Tamil Nadu, India, Phone: +91 9500058376, e-mail:
Aim And Objective: To evaluate and compare the impact of nanocoatings made of oxides of Aluminum, Titanium, and Zirconium, on the frictional resistance on three types of superelastic orthodontics archwires namely; nickel titanium, copper nickel titanium and low hysteresis nickel titanium.
Materials And Methods: There are120 archwire segments of equal dimensions were divided into four groups ( = 30) with 10 samples each of low hysteresis superelastic archwires; NiTi archwires and CuNiTi archwires. While group A were uncoated, other groups were nanocoated with group B: Aluminum oxide; group C: Titanium dioxide; group D: Zirconium oxide respectively.
Int Orthod
November 2024
Department of Orthodontics, Louisiana State University Health-New Orleans, School of Dentistry, 1100 Florida Avenue, 70119 New Orleans, LA, USA. Electronic address:
Purpose: Orthodontic treatment often involves bonding brackets to teeth, and the protocols for natural enamel differ from those for prosthodontically restored teeth. With the rising number of adult orthodontic patients, many present with zirconia crowns. This study aimed to evaluate the shear bond strength (SBS) of ceramic orthodontic brackets bonded to transition dental zirconia, which combines 3Y-TZP and 5Y-TZP powders.
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