Evaluation of the effects of different composite materials and surface roughening techniques in bonding attachments of clear aligner on monolithic zirconia.

Objective: The aim of this study is to evaluate the bond strengths of two different composite types used in the production of clear aligner attachments on monolithic zirconia with three different surface roughening processes. Materials and Methods: Packable composite Filtek Z250 was used in one group (PC‐G) and flowable composite Filtek Supreme Ultra Flowable was used in the other group (FC‐G). PC‐G and FC‐G groups were also divided into three subgroups as diamond bur+silane (Group 1), 50 μm aluminium oxide (Al2O3) sandblasting+silane (Group 2) and 110 μm Al2O3 sandblasting+silane (Group 3). Scanning electron microscopy (SEM) analysis was performed. Clear aligner attachments were bonded to the monolithic zirconia specimens. Shear bond strength (SBS) values were measured. Statistical analysis was performed using two‐way ANOVA and post‐hoc Tukey's tests (P <.05). Results: The highest SBS value was found in PC‐G sandblasted with 110 μm Al2O3 (P ≤.001). The etching method with 110 μm sandblasting showed high SBS values in both composite types. The lowest SBS value gave FC‐G in diamond bur roughening (P ≤.001). Conclusions: For the bonding of clear aligner attachments on monolithic zirconia, roughening with 110 μm particle size sandblasting and the choice of packable composite could be recommended in terms of retention. [ABSTRACT FROM AUTHOR]