Comparative effects of tungsten, diamond burs and laser for residual adhesive removal after orthodontic debonding on flexural strength, surface roughness and phase transformation of high-translucent zirconia: An in vitro study - 07/08/22
Abstract |
Objectives |
Information regarding the effects of orthodontic bracket debonding on zirconia restorations, and the preferred method for residual adhesive removal from the zirconia restoration surface is lacking. Thus, this study aimed to assess the effects of different methods of residual adhesive removal after orthodontic bracket debonding on flexural strength, surface roughness, and phase transformation of high-translucent (HT) zirconia.
Materials and methods |
This in vitro study evaluated 72 bar-shaped HT zirconia specimens; 18 specimens were assigned to the control group. Metal brackets were bonded to the remaining specimens by resin cement. After bracket debonding, the residual adhesive on the surface of specimens was removed by three methods (n=18): a 30-flute tungsten-carbide (TC) bur at low speed, an ultrafine diamond bur at high speed, and Er:YAG laser irradiation. The surface roughness (Ra and Rz) was measured. X-ray diffraction (XRD) analysis was carried out, and the flexural strength was measured as well. Data were statistically analyzed (α=0.05).
Results |
Before polishing, all methods increased the Ra and Rz values (P<0.05) except for the diamond bur yielding a Rz value comparable to that of the control group. The Ra values of the test groups were comparable after polishing, and still higher than that of the control group (P<0.05). The flexural strength of all three test groups was comparable (P>0.05), and significantly lower than that of the control group (P<0.001). The monoclinic phase was not observed in any group.
Conclusions |
Orthodontic bracket debonding adversely affects the surface roughness and flexural strength of zirconia despite polishing.
Le texte complet de cet article est disponible en PDF.Keywords : Bracket, Orthodontic debonding, Dental Polishing, SEM, Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP Ceramic), X-Ray Diffraction
Plan
Vol 20 - N° 3
Article 100665- septembre 2022 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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