NaF-PVA tape that attaches to teeth by adding fluoride to polymer tape was developed in the Department of Pediatric Dentistry, Chosun University. A NaF-PVA pullulan double adhesive tape, which improved tensile strength and elongation by adding a pullulan to the NaF-PVA adhesive tape, was developed to enhance adhesion to the tooth surface. Previous studies have demonstrated the efficacy of NaF-PVA tape on teeth, but studies on stability and effects on bacteria have been insufficient. In this study, cytotoxicity and antibacterial tests of three groups (group 1: general tape without fluoride; control group, group 2: adhesive tape containing fluoride, group 3: double adhesive tape containing fluoride with pullulan) were conducted.
To investigate the antibacterial effect of the NaF tapes, the agar diffusion technique was performed using Mitis salrivarius agar plates. Also, field emission scanning electron microscopy (FE-SEM) and confocal laser scanning microscopy (CLSM) were performed.
The cytotoxicity test was performed using human gingival fibroblast (HGF) and human periodontal ligament (PDL) cells. These cells were subjected to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay by applying an adhesive tape containing fluoride, and genetic analysis of the cells was performed to conduct a stability test in humans.
In the antibacterial test, Group 2 (NaF-PVA tape group) showed the highest zone of inhibition at 48 hours, and this result was significantly higher than that of the control group and group 3 (pullulan + NaF-PVA tape group). In the MTT assay, Group 3 (pullulan + NaF-PVA tape group) had more cytotoxicity than the control group by 66% in PDL and 69% in HGF. Interestingly, even though group 2 (NaF-PVA tape group) had more antibacterial effect against S. mutans, it showed less cytotoxicity than group 3 (pullulan + NaF-PVA tape group) by 29% in PDL and 33% in HGF. A value that can support the results of the MTT test was also derived in a biostability experiment through genetic analysis.