The effect of Padma-hepaten herbal combination on the caries-inducing properties of Streptococcus mutans on orthodontic surfaces

Abstract Dental biofilm is recognized as the primary cause of oral infections, caries being the most common. Orthodontic appliances might increase the risk for dental caries and white spot lesions. Phytomedicinal methods were shown to inhibit dental biofilm formation. The goal of this study was to examine whether Padma hepaten (PH), a polyphenolic formula derived from traditional Tibetan medicine, could inhibit the caries-inducing properties of S. mutans. Biofilms of S. mutans were grown in the presence of PH. Formation of biofilms was tested spectrophotometrically. Exopolysaccharides (EPS) secretion was quantified using confocal scanning laser microscopy. Gene expression of caries-related genes was tested using qRT-PCR. Development of biofilm was also tested on an orthodontic surface (Essix) to assess biofilm inhibition ability on such orthodontic appliances. PH had a dose-dependent inhibition on biofilm formation, with no inhibition on planktonic bacterial growth. The minimal biofilm concentration needed to inhibit the formation by 50 % was 0.16 mg/ml PH. This concentration inhibited EPS secretion by 88 %. A strong reduction was found in the expression of gtfB, gtfC, ftf and brpA caries associated genes. These results demonstrate the inhibitory effect of natural PH polyphenolic extraction on S. mutans biofilm formation and EPS secretion. In an era of increased bacterial resistance to antibiotics, the use of herbal medicine to inhibit biofilm development, without killing host cells, may pave the way to a novel therapeutic concept, especially in children as orthodontic patients.