Ahmed I. Abdul-Aziz, Sayed F. Abdelwahab And Wael M. Refai,

ABSTRACT
Background: Orthodontic Treatment With Fixed Appliances Increases Biofilm Accumulation On The Irregular Surfaces Of The Brackets Which May Lead To Enamel Demineralization. Data Examining The Adhesion Of Different Cariogenic Bacteria To Orthodontic Brackets With Different Methods Of Ligation Are Limited. Objective: To Quantitatively Analyse The Adhesion Of Streptococcus Mutans (S. Mutans) And Lactobacillus Casei (L. Casei) To Orthodontic Brackets With Different Ligation Methods.

Materials and Methods: Premolar Metal Brackets Were Incubated With 1?2?108 CFU/ml Of S. Mutans And L. Casei Alone And In Combination At 37�C For 24 H. Adhesion To Elastomeric Ligatures, Steel Wire Ligatures, And Self-ligating Brackets Was Quantified.

Results: S. Mutans Showed The Highest Adhesion To Elastomeric Ligatures, While L. Casei Showed The Highest Adhesion To The Self-ligating Brackets With Lowest Adhesion Of Both Strains To Brackets With Steel Wire Ligatures. Combination Of S. Mutans And L. Casei Resulted In A Much Lower Adhesion Of S. Mutans To All Types Of Ligation Compared To L. Casei.

Conclusions: The Ligation Method And Bacterial Combinations Played An Important Role In Bacterial Adhesion To Different Methods Of Ligation. These Data Should Guide The Choice Of Steel Wire Ligatures In Orthodontic Practice Particularly For Patients With Bad Oral Hygiene And High Caries Index.