Soybean Extracts Facilitate Bacterial Agglutination and Prevent Biofilm Formation on Orthodontic Wire

Abstract

Soybean is an essential food ingredient that contains a class of organic compounds known as isoflavones. It is also well known that several plant agglutinins interfere with bacterial adherence to smooth surfaces. However, little is known about the effects of soybean extracts or genistein (a purified isoflavone from soybean) on bacterial biofilm formation. We evaluated the effects of soybean (Glycine max) extracts, including fermented soybean and genistein, on streptococcal agglutination and attachment onto stainless steel orthodontic wire. After cultivating streptococci in biofilm medium containing soybean extracts and orthodontic wire, the viable bacteria attached to the wire were counted. Phase-contrast microscopy and scanning electron microscopy (SEM) analyses were conducted to evaluate bacterial agglutination and attachment. Our study showed that soybean extracts induce agglutination between streptococci, which results in bacterial precipitation. Conversely, viable bacterial counting and SEM image analysis of Streptococcus mutans attached to the orthodontic wire show that bacterial attachment decreases significantly when soybean extracts were added. However, there was no significant change in pre-attached S. mutans biofilm in response to soybean. A possible explanation for these results is that increased agglutination of planktonic streptococci by soybean extracts results in inhibition of bacterial attachment onto the orthodontic wire.

The Microflora Diversity and Profiles in Dental Plaque Biofilms on Brackets and Tooth Surfaces of Orthodontic Patients

“…We set the effect size of 1.0, a power of 0.9, and a significance level of .05, which calculated our sample size to be 5. 14 Five healthy participants were recruited for the study. Inclusion criteria were as follows: (1) Subject population should consist of 3 women and 2 men with an average age of 26.5 (±2.20) years; (2) population should have both genders; (3) all ethnicities should be included; (4) complement of all permanent teeth from second molar to second molar; (5) no crowns, labial bondings, or laminates on designated teeth; and (6) good alignment of teeth.…”

“…Porphyromonas gingivalis was grown in brain heart infusion (BHI) broth containing hemin and vitamin K at 37°C in an anaerobic chamber. 14 Aggregatibacter actinomycetemcomitans was grown in trypticase soy broth supplemented with yeast extract and glucose. The plates were inoculated at 37°C in 10% CO 2 for 48 hours.…”

Anti-Adherence and Antimicrobial Activities of Silver Nanoparticles against Serotypes C and K of Streptococcus mutans on Orthodontic Appliances

“…Particularly, some studies have described that specific compounds in the fabrication of orthodontic appliances can be related to the bacterial adherence of cariogenic bacteria associated with their manufacturing and complex design [ 45 ]. The SS has been identified as a material with a high potential for microbial adherence due to surface energy [ 72 , 73 ]; but also, it has demonstrated to have a low adherence affinity with S. mutans compared to other materials such as plastics and ceramics [ 74 ]. In addition, authors have reported that CuNiTi wire had higher levels of bacterial adherence compared to NiTi when they were exposed to the S. mutans strain, possibly due to differences in rougher surface and higher surface free energy [ 75 ].…”