Propolis Varnish: Antimicrobial Properties against Cariogenic Bacteria, Cytotoxicity, and Sustained-Release Profile

Abstract

Varnishes are preparations that differ in the polymeric matrix and therapeutical agents. In dentistry they are used to prevent caries. In this study we developed a propolis varnish, considering propolis properties against cariogenic bacteria. To a chitosan polymeric base (CHV) was added ethanolic propolis extract in different concentrations: PV1 (5%), PV2 (10%), and PV3 (15%). Antimicrobial activity was carried out against Streptococcus mutans (SM), Streptococcus sanguinis (SG), Streptococcus salivarius (SS), and Lactobacillus casei (LC) through agar diffusion method. The three propolis concentrations incorporated were effective in inhibiting the growth of all microorganisms, but without significant difference between the zones of inhibition observed. Cytotoxicity assay was done by MTT method. Data were analyzed by one-way ANOVA and Bonferroni test. None of the varnishes were cytotoxic, keeping 80% of viable cells, while CHV allowed cellular proliferation (120%). Sustained-release test was carried out by applying 40 μL of each varnish in the buccal surface of bovine teeth and kept in an ethanol/water solution removed in regular times. According to the “independent model approach,” the release profiles were distinct from each varnish and the most prolonged was PV3 (8 weeks). Varnish formulations had satisfactory antimicrobial activity against cariogenic bacteria and have a low cytotoxicity (<50%).

Antibacterial activity against Streptococcus mutans and inhibition of bacterial induced enamel demineralization of propolis, miswak, and chitosan nanoparticles based dental varnishes

“…Disk diffusion method was used to measure S. mutans sensitivity to the experimental varnishes [9], [35]. Thirty mL of freshly prepared and autoclaved brain heart infusion (BHI) agar was poured into sterile glass petri dishes.…”

The anti-caries activity and toxicity of an experimental propolis-containing varnish

“…19 An experimental propolis-containing varnish was developed by our research group, as reported elsewhere. 20 Our previous findings demonstrated that the experimental varnish has in vitro antimicrobial activity against cariogenic bacteria, and showed a very satisfactory sustained release of propolis in vitro. 20 These data have encouraged us to investigate the anti-caries activity of this experimental formulation, using an animal model under a high cariogenic challenge.…”

“…20 Our previous findings demonstrated that the experimental varnish has in vitro antimicrobial activity against cariogenic bacteria, and showed a very satisfactory sustained release of propolis in vitro. 20 These data have encouraged us to investigate the anti-caries activity of this experimental formulation, using an animal model under a high cariogenic challenge. Herein, we investigated the anti-caries effects of the experimental propolis varnish in a rat model, and further tested its toxicity against fibroblasts, to provide enough information to perform clinical trials and eventually promote future clinical use.…”

“…The materials tested were: a. culture medium + cells (control), b. culture medium, c. PV (type 12 propolis from southeastern Brazil -propolis ethanolic extract, 15%, w/v), d. CV (varnish base, vehicle control), e. gold-standard (GS) varnish (Duraphat, fluoride 2.26%, w/v, positive control), and f. acetic acid (1%, v/v). 20 One millimeter of each product was placed on round glass coverslips (9-mm diameter) and dried under vacuum for 24 h. Then the fibroblasts were plated into 48-well microtiter plates (4 x 10 5 cells/well). After 4 h, the cells received conditioned media respective to each experimental group.…”

The Potential of Several Fluoride-Based Varnishes as Remineralization Agents: Morphological Studies, Dentin Surface Hardness, and Crystallinity Tests

“…Fluoride is available in a variety of dosage forms including sodium diamine fluoride (SDF), nanosilver fluoride (NSF), and propolis fluoride (PPF) [4][5][6][7][8][9][10][11][12][13][14]. Previous studies using SDF have shown that SDF consists of silver (Ag) and fluoride (F); silver acts as an antimicrobial agent and fluoride plays a role in enhancing remineralization as a strong anticaries agent [11].…”