Comparison of Shear Bond Strength and Estimation of Adhesive Remnant Index Between 3D Printed Customised Lingual...

Aim The main aim of this study is to compare the shear bond strength (SBS) of 3D-printed customised lingual buttons and prefabricated lingual buttons. Methodology Forty-eight extracted maxillary premolar teeth were selected. Teeth were allocated to two groups of 24 each; in one group, customised lingual buttons were fabricated using 3D printing. Prefabricated lingual buttons were bonded to one group, while the other group was bonded with the customised lingual buttons. The samples were preserved in distilled water at 37⁰C for 24 hours. The samples were evaluated for SBS using a universal testing machine, and the adhesive remnant index (ARI) was determined under a stereomicroscope at 10× magnification. Statistical analysis included the Mann-Whitney U test for SBS and the chi-square test for ARI scores. Results The mean SBS of prefabricated and customised 3D-printed lingual buttons was estimated to be 2.331 ± 2.549 MPa and 3.694 ± 2.564 MPa, respectively. The Mann-Whitney U test conducted to analyse the SBS showed a significant difference between the two groups at p < 0.05. ARI scores indicated that prefabricated lingual buttons had an ARI score of 3 predominantly, while customised 3D-printed lingual buttons had a predominant score of 1. This was statistically significant. Conclusion Customised 3D-printed lingual buttons showed superior SBS compared to the prefabricated lingual buttons. Bond failure was noted more at the bracket-adhesive interface in the prefabricated lingual button group, while it was a cohesive failure close to the enamel surface in the case of customised lingual buttons.