Shear bond strength of orthodontic brackets bonded with primer-incorporated orthodontic adhesives and unpolymerized 3-dimensional printing materials on 3-dimensional-printed crowns

Yukyung Choi; Wonjoon Moon; Adriana P Manso; Young-Seok Park; Bum-Soon Lim; Shin Hye Chung

doi:10.1016/j.ajodo.2024.01.013

Shear bond strength of orthodontic brackets bonded with primer-incorporated orthodontic adhesives and unpolymerized 3-dimensional printing materials on 3-dimensional-printed crowns

Am J Orthod Dentofacial Orthop. 2024 Mar 21:S0889-5406(24)00060-X. doi: 10.1016/j.ajodo.2024.01.013. Online ahead of print.

Authors

Yukyung Choi¹, Wonjoon Moon², Adriana P Manso³, Young-Seok Park⁴, Bum-Soon Lim¹, Shin Hye Chung⁵

Affiliations

¹ Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
² Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Cambridge, Mass.
³ Department of Oral Health Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada.
⁴ Department of Oral Anatomy, Dental Research Institute, Center for Future Dentistry, School of Dentistry, Seoul National University, Seoul, South Korea.
⁵ Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea. Electronic address: den533@snu.ac.kr.

PMID: 38520414
DOI: 10.1016/j.ajodo.2024.01.013

Abstract

Introduction: The use of 3-dimensional (3D) printing techniques in fabricating crowns has increased the demand for bracket bonding onto these surfaces. The objective was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded onto 3D-printed crowns using primer-incorporated orthodontic adhesives and 3D printing materials as orthodontic adhesives.

Methods: A total of 160 crowns were printed with 2 3D printing materials, DentaTOOTH (Asiga, Sydney, Australia) (group A) and NextDent C&B Micro Filled Hybrid (3D Systems, Soesterberg, Netherlands) (group N). Each group was randomly divided into 4 adhesive subgroups (n = 20): Transbond XT (for groups A [ATX] and N [NTX]; 3M Unitek, Monrovia, Calif), Ortho Connect (for groups A [AOC] and N [NOC]; GC Corporation., Tokyo, Japan), Orthomite LC (for groups A [AOM] and N [NOM]; Sun Medical, Co Ltd, Moriyama, Shiga, Japan), and unpolymerized liquid state of 3D printing resin (for groups A [AA] and N [NN]). SBS was measured with a universal testing machine at a crosshead speed of 0.5 mm/min. The adhesive remnant index and the mode of failure were analyzed under the microscope. Statistical analysis was performed at a significance level of α = 0.05.

Results: When used as adhesives (AA and NN), 3D printing materials showed no statistically significant difference in SBS compared with Transbond XT (ATX and NTX, respectively). In group N, NN showed a significantly higher SBS than primer-incorporated orthodontic adhesives (NOC and NOM; P <0.001). Adhesive failures were only observed in primer-incorporated orthodontic adhesives (AOC, NOC, AOM, and NOM).

Conclusions: Primer-incorporated orthodontic adhesives, as well as unpolymerized 3D printing materials employed as orthodontic adhesives on 3D-printed crowns, exhibited comparable bonding strength to Transbond XT without surface modification. Despite variations in adhesive-related factors, all measurements stayed within clinically acceptable ranges, highlighting the potential of these materials for orthodontic bonding on 3D-printed crowns, simplifying clinical procedures without compromising bond strength.