Korean J Dent Mater.  2020 Jun;47(2):83-92. 10.14815/kjdm.2020.47.2.83.

Shear bond strength between orthodontic metal brackets and Y-TZP according to the various ceramic surface treatments before and after thermocycling

• Choi JB
• Byeon SM

• KMID: 2504115
• DOI: http://doi.org/10.14815/kjdm.2020.47.2.83

Abstract

In this study, clinically applicable methods of improving the bond strength between Y-TZP and the bracket were considered, which the method was confirmed for the durability in a humid oral environment. The bond strength of Y-TZP bonding surface and the surface characteristics were analyzed following the surface treatment of Y-TZP specimens with conditioning by 30 μm tribochemical silica coating, or tribochemical silica coating with one of the following primers: silane, MDP, or an MDP-containing silane primer. It was found that after surface treatment, the surface roughness of all groups increased (p<0.05), and Si was uniformly distributed on the Y-TZP surface after silica coating. The bond strength value of the group treated with silane primer and tribochemical coating was not significantly different after thermocycling (p>0.05). The group treated with MDP primer and tribochemical silica coating showed a significant difference in bond strength values after thermocycling (p<0.05), and it showed the lowest bond strength values except the untreated groups (p<0.05). The group treated with tribochemical silica coating and MDP-containing silane primer showed the highest bond strength values (p<0.05), and was not significantly different after thermocycling (p>0.05). Therefore, the surface treatments of Y-TZP with MDP-containing silane primer after 30 μm tribochemical silica coating enhanced the bond strength to the orthodontic metal bracket; such a clinically applicable method may advance studies on the surface treatment of Y-TZP.

Keyword

Y-TZP; Tribochemical silica coating; Primer; Shear bond strength; Thermocycling