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

Area of Science:

• Orthodontics
• Microbiology
• Biomaterials

Background:

• Self-ligating brackets are hypothesized to improve oral hygiene.
• However, scientific consensus on their reduced bacterial adhesion remains elusive.

Purpose of the Study:

• To compare in vitro Streptococcus mutans (SM) adhesion on self-ligating versus conventional orthodontic brackets.
• To evaluate adhesion across different manufacturers and ligature types.

Main Methods:

• Four brands of metal premolar brackets were tested: Abzil®, Morelli®, 3M Unitek®, and GAC®.
• Brackets were categorized into metallic, elastic, and self-ligating groups.
• Sterilized brackets were incubated in saliva, then bacterial suspension, followed by quantification of adhered bacteria (CFU/mL).

Main Results:

• Self-ligating brackets exhibited significantly lower bacterial counts (CFU/mL) overall.
• Abzil® self-ligating brackets showed significantly reduced biofilm adhesion within their brand comparison.
• GAC® self-ligating brackets displayed the highest bacterial adhesion among all tested self-ligating models.

Conclusions:

• Self-ligating brackets generally appear to reduce biofilm adhesion.
• Abzil® and GAC® self-ligating brackets show potential for lower biofilm accumulation.
• Findings suggest bacterial adhesion is a key factor for practitioners selecting orthodontic brackets.