Rapid kill-novel endodontic sealer and Enterococcus faecalis.

With growing concern over bacterial resistance, the identification of new antimicrobial means is paramount. In the oral cavity microorganisms are essential to the development of periradicular diseases and are the major causative factors associated with endodontic treatment failure. As quaternary ammonium compounds have the ability to kill a wide array of bacteria through electrostatic interactions with multiple anionic targets on the bacterial surface, it is likely that they can overcome bacterial resistance. Melding these ideas, we investigated the potency of a novel endodontic sealer in limiting Enterococcus faecalis growth. We used a polyethyleneimine scaffold to synthesize nano-sized particles, optimized for incorporation into an epoxy-based endodontic sealer. The novel endodontic sealer was tested for its antimicrobial efficacy and evaluated for biocompatibility and physical eligibility. Our results show that the novel sealer foundation affixes the nanoparticles, achieving surface bactericidal properties, but at the same time impeding nanoparticle penetration into eukaryotic cells and thereby mitigating a possible toxic effect. Moreover, adequate physical properties are maintained. The nanosized quaternary amine particles interact within minutes with bacteria, triggering cell death across wide pH values. Throughout this study we demonstrate a new antibacterial perspective for endodontic sealers; a novel antibacterial, effective and safe antimicrobial means.

Antibacterial effect of polyethyleneimine nanoparticles incorporated in provisional cements against Streptococcus mutans.

BACKGROUND: Frequently provisional restorations require long-term permanence in the oral cavity, thus an antibacterial effect is desirable. We hypothesized that this effect may be achieved by incorporating polyethyleneimine (PEI) nanoparticles into provisional cements. METHODS: The nanoparticles antibacterial effect incorporated at 0.5%, 1%, and 2% w/w into provisional cement, was studied in vitro. The antibacterial effect against Streptococcus mutans and Enterococcus faecalis was tested using direct contact test. The data was analyzed using the ANOVA test, with the Dunnett test for multiple pairwise comparisons. RESULTS: A strong antibacterial effect was evident in all test groups after an aging period of 14 days against S. mutans and E. faecalis (p < 0.05). A significant effect was found between study groups 0.5% w/w and 1% w/w group, as well as between study groups 0.5% w/w and 2% w/w for E. faecalis (p < 0.05). No significant difference was found between study groups 1% w/w and 2% w/w. The growth rate graphs depict an effective bacteria inhibition starting from 1% w/w. CONCLUSION: PEI nanoparticles incorporated at low concentrations in a provisional cement exhibit antibacterial effect against S. mutans and E. faecalis for a period of 14 days. The minimum effective concentration suggested is 1% w/w. CLINICAL IMPLICATIONS: Incorporation of nanoparticles may prevent caries and inflammation, and thereby improve the results of the prosthetic treatment. Further investigation is necessary on the effect on mechanical properties and clinical relevance.

Effect of liquid-polish coating on in vitro biofilm accumulation on provisional restorations: Part 2.

OBJECTIVE: In part 1 of this study, the authors showed that coating polymethyl methacrylate (PMMA) provisional restorations with bonding resin (BR) or liquid polish (LP) significantly reduced early in vivo biofilm formation on these restorations. The aim of the present study was to determine the mechanism through which these materials inhibit biofilm formation. METHOD AND MATERIALS: The antimicrobial properties of the tested materials were examined using the agar diffusion test (ADT) and the direct contact test (DCT). Surface energy was determined using contact angle measurements; salivary protein adsorption was analyzed by polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: ADT and DCT showed that the tested materials had no antimicrobial properties. Contact angle measurements revealed that liquid polish and PMMA have a similar contact angle, tending toward the hydrophobic region, and that bonding resin was more hydrophilic. SDS-PAGE analysis showed a significant reduction in salivary protein adsorption to the tested materials compared with that to the PMMA control. CONCLUSION: Liquid polish prevents biofilm formation by preventing protein adsorption.

Oral malodor reduction by a palatal mucoadhesive tablet containing herbal formulation.

OBJECTIVE: The aim of the present study was to test the effect of a palatal mucoadhesive tablet containing an herbal formulation on oral malodor production and volatile sulfide compound (VSC) levels, and to evaluate its antimicrobial activity. METHODS: A total of 56 healthy young volunteers participated in experiments 1 and 2. The palatal adhesive tablets were prepared with different active ingredients (herbal formulation, zinc and chlorhexidine), or without an active ingredient as control (placebo). Measurement included odor judge scores (two judges) and VSC readings by a sulfide monitor (Halimeter). In experiment 3, the antimicrobial activity of the herbal formulation ingredients (i.e. sage, Echinacea, Lavender and Mastic gum) were tested against three oral pathogens (Streptoccocus mutans, Porphyromonas gingivalis and Candida albicans) by the agar diffusion test. RESULTS: Application of the palatal adhesive tablets containing herbal formulation resulted in a significant reduction in both oral malodor scores (p<0.001) and VSC levels (p=0.013). Herbal formulation showed higher significance in VSC reduction (p=0.001), as compared to zinc and chlorhexidine (p=0.024 and 0.032, respectively). Sage, Lavender and Mastic gum showed antimicrobial activity against all three oral pathogens. CONCLUSIONS: Results of the present study suggest that the palatal adhesive tablets containing herbal formulation may serve as an effective means of treatment for patients complaining of oral malodor.