Evaluation of Different Surface Roughening Techniques on Clear Aligner Attachments Bonded to Monolithic Zirconia: In Vitro Study.

Abstract

Aim: The objective of this study is to assess the impact of three different surface etching techniques and two composite materials on surface roughness (R_a) and the shear bond strength (SBS) of clear aligner attachments bonded to monolithic zirconia (MZ).

Materials and methods: Sixty-six MZ disks were divided into three main groups (n = 22) according to the surface treatment method: group I: hydrofluoric acid (HFA) 9.5%, group II: 50 µm aluminum oxide (Al₂O₃) sandblasting, and group III: Er:Cr:YSGG laser. Each group was then subdivided into two subgroups according to the composite material (n = 11) used for bonding of the attachment, either packable composite Filtek Z350 or composite Filtek Z250. Clear aligner attachments were then bonded to the disks, and measurements of R_a and SBS were taken. Statistical analysis was carried out using the Kruskal-Wallis test and two-way analysis of variance.

Results: The HFA groups showed the highest SBS (11.29 ± 2.83 MPa) and R_a (0.82 µm), while the laser groups exhibited the lowest SBS (8.29 ± 2.38 MPa) and R_a (0.634 µm). In Filtek Z350, there was a significant difference observed between the subgroups regarding SBS but not in Filtek Z250 subgroups.

Conclusion: The 9.5% HFA provided the highest SBS value in comparison with Er:Cr:YSGG laser and sandblasting (p <0.05).

Clinical significance: This study has the potential to benefit both orthodontists and patients by providing insights into techniques that can improve the bond strength and longevity of clear aligner attachments to MZ. How to cite this article: Alhunayni AS, Albelasy NF, Hafez AM. Evaluation of Different Surface Roughening Techniques on Clear Aligner Attachments Bonded to Monolithic Zirconia: In Vitro Study. J Contemp Dent Pract 2024;25(12):1104-1109.