The microorganisms most dominant on the aligners after only a day of wearing them were Bifidobacteria, yeast-like fungi of the genus Candida, Escherichia coli, Peptostreptococcus anaerobius, Porphyromonas gingivalis, Prevotella buccae, Staphylococcus aureus and Streptococcus mitis. The researchers were also able to identify the microorganisms that were the strongest producers of biofilm and thereby exert a predominant influence in the ecological community.
Because of the risk of reduced effectiveness of anti-inflammatory therapy and the development of caries and other inflammatory diseases, biofilm formation during therapy requires constant monitoring. Scientists have thus focused on the interaction between aligners and the oral microflora, especially regarding species composition and antibiotic resistance. Oral microorganisms and their properties, such as biofilm formation, adhesion and the ability to incorporate solid particles, change over time, according to location and under certain conditions. Studies cited by the researchers therefore suggested that longer-term investigations would be necessary to evaluate whether the levels and variety of microflora in the mouth associated with the use of orthodontic appliances return to pre-intervention levels.