Evaluation of the Contamination of Ligatures

The development of dental plaque has been associated with several environmental and individual factors including diet composition, oral hygiene, the quality of saliva, the composition of the oral microflora and immune factors. Orthodontic fixed appliances also impede the maintenance of oral hygiene. Plaque accumulation surrounding orthodontic appliances leads to enamel demineralization caused by organic acids produced by bacteria in the dental plaque.

In patients with fixed orthodontic treatment, common pathological changes are gingivitis, bleeding and gingival growth; thus, gingival index and plaque index parameters have been used as indicators of periodontal disease in many studies. Enamel demineralization which results in white spot formation is observed due to the increase in the number and volume of acid-producing bacteria, and the decrease in pH level because of the glucose metabolized by these cariogenic bacteria . The most commonly investigated bacteria among those mentioned above is Streptococcus Mutans. In the literature, it has been the subject of many studies, including those investigating the correlation between the S. mutans count and the amount of adhesive left between brackets and the enamel, adhesion of S. mutans to nickel titanium and copper-nickel brackets, the difference in S. mutans colonization between self-ligation system and normal brackets, and the effect of elastomeric rings and ligature wires on S. mutans colonization.

Non-conventional elastomeric ligatures were produced in order to reduce the friction of orthodontic sliding mechanics. Manufacturers claim that non-conventional elastomeric ligatures reduced ligation friction by 60% compared to conventional modules. It was reported in another study that brackets combined via non-conventional elastomeric ligatures resulted in a reduced friction force compared to conventional elastomeric ligatures in any wires from 14-inch NITI to 19.25 SS.

To our current knowledge, bacterial colonization on non-conventional elastomeric ligatures was investigated in one study only, using microbial culture technique. In light of this information, present study was aimed to compare S. mutans colonization among different commercial types of non-conventional ligatures and ligature wires. The surface structures of these ligature types also will be investigated by atomic force microscope (AFM) and the results of this investigation will be associated with the results of bacterial colonization amount.

Inclusion criteria

• permanent teeth in the mouth
• patients with good oral hygiene
• patients did not use antimicrobial drugs such as antibiotics and mouthwashes 3 weeks before the study period and within the 18-week period covering the study period.

Exclusion criteria

• smoker