Antibacterial Activity and Shear Bond Strength of Orthodontic Adhesive Containing Various Sizes of Chitosan Nanoparticles: An In Vitro Study

Reem Almeshal; Sarah Pagni; Ala Ali; Driss Zoukhri

doi:10.7759/cureus.54098

Antibacterial Activity and Shear Bond Strength of Orthodontic Adhesive Containing Various Sizes of Chitosan Nanoparticles: An In Vitro Study

Cureus. 2024 Feb 12;16(2):e54098. doi: 10.7759/cureus.54098. eCollection 2024 Feb.

Authors

Reem Almeshal¹, Sarah Pagni², Ala Ali³, Driss Zoukhri⁴

Affiliations

¹ College of Dentistry, Tufts University, Boston, USA.
² Department of Public Health and Community Service, Tufts University School of Dental Medicine, Boston, USA.
³ Department of Prosthodontics and Operative Dentistry, Tufts University School of Dental Medicine, Boston, USA.
⁴ Department of Comprehensive Care, Tufts University School of Dental Medicine, Boston, USA.

Abstract

Introduction: White spot lesions are common after orthodontic treatment. Chitosan nanoparticles (CS-NPs) have emerged as promising antibacterial agents that inhibit the growth of Streptococcus mutans. The aim of the study was to investigate the nano-effect of adhesives containing CS-NPs on S. mutans and their effects on shear bond strength.

Materials and methods: The inhibitory effects of two sizes of CS-NPs were assessed using the disc agar diffusion method. Four wells were created in the petri dishes, and each was inoculated with broth (negative control), chlorhexidine (positive control), CS-NPs (20 nm), or CS-NPs (131 nm). An Instron machine was used to evaluate shear bond strength by allocating 24 teeth into three groups, and all measurements were recorded in megapascals. Caries progression was assessed using the International Caries Detection and Assessment System and surface profilometry. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 27.0 (Released 2020; IBM Corp., Armonk, New York, United States) for a one-way ANOVA followed by Tukey's multiple comparison test.

Results: Disc agar diffusion showed a reduction in S. mutans in the CS-NP group compared to the control (p < 0.001), with no statistical significance between the sizes of 20 and 131 nm (p = 0.95). Regarding shear bond strength, no differences were recorded when adhesive-containing CS-NPs and the control were compared (p = 0.44). Additionally, no differences were found within the CS-NP groups (p = 0.91). Caries assessments showed excellent agreement, as indicated by a weighted kappa. Profilometry readings showed higher surface roughness in the control than in the CS-NP groups (p < 0.001), with no statistically significant difference between the CS-NP groups (p = 0.72).

Conclusion: CS-NPs of both sizes tested had similar antibacterial effects. In addition, the incorporation of CS-NPs did not affect shear bond strength.

Keywords: chitosan; orthodontic adhesive; shear bond strength; streptococcus mutans; white spot lesions.