Fig. 3: Pulsed electromagnetic field (PEMF) evaluated in terms of in vitro polymicrobial biofilm formation.

A Stimulated human saliva (5 healthy volunteers) was used as microbial inoculum/source. Biofilms were incubated for 24 and 72 h and evaluated in terms of live bacterial cells count, structure, pH and composition. B Colony-forming units (CFU) for total live cell counts. Biofilm suspension was serially diluted and plated on Columbia Blood Agar (CBA) for measures. C Biofilm pH medium as bacterial metabolism analysis was evaluated at the beginning and after 72 h, using a pH meter. D Scanning electron microscopy micrographs of both groups after 72 h of biofilm formation. The circles and yellow lines represent microbial (streptococcal) aggregates or mixed-species aggregation on the surface. * Indicates statistical difference (p < 0.05) by t-test.