Bacterial adhesion on conventional and self-ligating metallic brackets after surface treatment with plasma-polymerized hexamethyldisiloxane

Abstract

Introduction: Plasma-polymerized film deposition was created to modify metallic orthodontic brackets surface properties in order to inhibit bacterial adhesion. Methods: Hexamethyldisiloxane (HMDSO) polymer films were deposited on conventional (n = 10) and self-ligating (n = 10) stainless steel orthodontic brackets using the Plasma-Enhanced Chemical Vapor Deposition (PECVD) radio frequency technique. The samples were divided into two groups according to the kind of bracket and two subgroups after surface treatment. Scanning Electron Microscopy (SEM) analysis was performed to assess the presence of bacterial adhesion over samples surfaces (slot and wings region) and film layer integrity. Surface roughness was assessed by Confocal Interferometry (CI) and surface wettability, by goniometry. For bacterial adhesion analysis, samples were exposed for 72 hours to a Streptococcus mutans solution for biofilm formation. The values obtained for surface roughness were analyzed using the Mann-Whitney test while biofilm adhesion were assessed by Kruskal-Wallis and SNK test. Results: Significant statistical differences (p< 0.05) for surface roughness and bacterial adhesion reduction were observed on conventional brackets after surface treatment and between conventional and self-ligating brackets; no significant statistical differences were observed between self-ligating groups (p> 0.05). Conclusion: Plasma-polymerized film deposition was only effective on reducing surface roughness and bacterial adhesion in conventional brackets. It was also noted that conventional brackets showed lower biofilm adhesion than self-ligating brackets despite the absence of film.

Influence of orthodontic brackets design and surface properties on the cariogenic Streptococcus mutans adhesion

“…On the other hand, the lower roughness presented by SLM brackets may have been compensated by the presence of the NiTi clip as a binding element that resulting in an additional site for bacterial adhesion and proliferation ( Tupinambá et al, 2017 ). It may have contributed to similar adherence data between these brackets and the others.…”

Streptococcus mutans adherence to conventional and self-ligating brackets: an in vitro study

“…Tupinambá et al 38 also comparatively evaluated conventional and self-ligating brackets - in this case, from Morelli ® commercial brand. While no significant differences were observed by the analysis employed here, the authors of that study 38 found lower bacterial adhesion to conventional brackets. However, these were processed without the presence of any type of ligature, either metallic or elastic.…”

Enhanced reduction of polymicrobial biofilms on the orthodontic brackets and enamel surface remineralization using zeolite-zinc oxide nanoparticles-based antimicrobial photodynamic therapy

“…The orthodontic brackets were placed in the 24-well plates (Ningbo Fuchun, China) with 1.5 mL BHI broth supplemented with 5% sucrose, and inoculated with 100 μL of each bacterial suspension at the concentration of 0.5 McFarland standard. The orthodontic brackets were incubated at 37 °C for 72 h under capnophilic conditions (5% CO 2 ) for the formation of polymicrobial biofilms [61]. After this time, the brackets were rinsed with PBS (pH 7.4) for removing non-adhered microorganisms.…”