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Published on: May 17, 2020
Comparative in vitro study of bond strength of two-step orthodontic bonding systems : Self-adhesive composite vs.
Marwan El Helou1,2,3, Eva Canamas4,5, Emmanuel Nicolas4,5
1Laboratory of Bioengineering and Nanosciences EA 4203, Dental School, University of Montpellier, 545 Avenue du Professeur Jean-Louis Viala, 34193, Cedex 5, Montpellier, France. marwan.el.helou@hotmail.com.
Purpose:
This in vitro study aimed to compare the shear bond strength (SBS) and Adhesive Remnant Index (ARI) scores of two-step orthodontic bonding systems: self-etching primer (SEP) and a self-adhesive composite. Both systems were compared to a control group with a conventional three-step adhesive.
Methods:
A total of 72 extracted maxillary and mandibular premolars were randomly divided into four groups (n = 18): group 1(XT), the control group, used Transbond™ XT (conventional adhesive; 3M Unitek, Monrovia, CA, USA); group 2 (GC) used GC Ortho Connect™ (self-adhesive composite; GC Orthodontics Inc., Tokyo, Japan); group 3 (GCP) used GC primer with GC Ortho Connect™; and group 4 (SEP) used Transbond™ Plus Self-Etching Primer with Transbond™ XT. Teeth were stored in water at 37 °C for 24 h prior to SBS testing using an Instron 5543 device (Instron, Norwood, MA, USA), and ARI scores were assessed under a stereomicroscope. Data were analyzed using analysis of variance (ANOVA) and nonparametric tests.
Results:
In total, 60 samples were analyzed. The GCP group exhibited the highest SBS (8.35 MPa ± 1.99), significantly higher than the XT (4.99 MPa ± 1.32, p < 0.001) and SEP (5.69 MPa ± 2.10, p = 0.001) groups. The GC group (7.50 MPa ± 1.92) also showed higher SBS than XT (p = 0.003) and the SEP group (p = 0.048). ARI scores showed no significant difference between groups overall (p = 0.303), but the GCP group had significantly higher ARI scores than the SEP group (p = 0.023).
Conclusion:
GC Ortho Connect™ with or without primer demonstrated superior bond strength compared to conventional and self-etching systems, making it a viable alternative for clinical use. Further in vivo studies are needed to confirm these findings.
