Table 1.
Materials, manufacturers, and full chemical compositions used in this study.
Fig 1.
Study workflow outlining specimen preparation.
Sandblasted zirconia crowns were bonded with customized lingual bracket bases manufactured either by 3D-printing or by casting. Two primers were evaluated: a 10-methacryloyloxydecyl dihydrogen phosphate (MDP) primer and a universal primer. Two polymerization modes were used: a light-cure orthodontic composite and a dual-cure resin cement. After bonding, specimens underwent thermocycling and were tested for shear bond strength.
Fig 2.
Representative scanning electron micrographs (1000×).
(A–C) Zirconia surfaces after sandblasting, with 10-methacryloyloxydecyl dihydrogen phosphate (MDP) primer, and universal primer. (D–F) 3D-printed bracket bases after sandblasting, with MDP primer, and universal primer. (G–I) Cast bracket bases after sandblasting, with MDP primer, and universal primer.
Table 2.
Results of three-way ANOVA on shear bond strength according to fabrication method, primer, and adhesive polymerization.
Table 3.
Shear bond strength by fabrication method and primer, stratified by adhesive polymerization type.
Fig 3.
Box plots of shear bond strength by bracket fabrication modality, primer category, and adhesive polymerization mode.
Fig 4.
Representative images of Adhesive Remnant Index (ARI) scores.
A, ARI 0: no adhesive remaining on the zirconia surface. B, ARI 1: less than 50% of the adhesive remaining on the zirconia surface. C, ARI 2: more than 50% of the adhesive remaining on the zirconia surface. D, ARI 3: all adhesive remaining on the zirconia surface.
Fig 5.
Stacked bar chart showing the distribution of Adhesive Remnant Index (ARI) scores (0-3) by bracket fabrication modality, primer, and adhesive polymerization mode.