Effects of Lactobacillus salivarius WB21 combined with green tea catechins on dental caries, periodontitis, and oral malodor.

OBJECTIVE: To evaluate the combined use of Lactobacillus salivarius WB21 and (-)-epigallocatechin gallate (EGCg) for oral health maintenance. DESIGN: The effects of L. salivarius WB21 on growth of Streptococcus mutans, the insoluble glucan produced by S. mutans, and on growth of Porphyromonas gingivalis were evaluated in vitro. In addition, the susceptibility of five oral pathogenic bacteria and L. salivarius WB21 to EGCg, the inhibiting effect of EGCg on methyl mercaptan, and the effects of L. salivarius WB21 and EGCg in combination on growth of P. gingivalis were examined. RESULTS: Lactobacillus salivarius WB21 showed concentration-dependent inhibition of the growth of S. mutans. Addition of L. salivarius WB21 inhibited production of the insoluble glucan by S. mutans (p < 0.001). A filtrate of L. salivarius WB21 culture solution inhibited growth of P. gingivalis (p < 0.001 vs. control), and this effect was enhanced when it was used in combination with EGCg (p < 0.001 vs. the addition of L. salivarius WB21). In addition, EGCg directly inhibited methyl mercaptan in a concentration-dependent manner (p < 0.001). Concerning bacterial susceptibility to EGCg, growth of P. gingivalis, Prevotella intermedia, and Fusobacterium nucleatum was inhibited at 2.5 mg/mL of EGCg, while that of L. salivarius WB21 was inhibited at 25 mg/mL EGCg. CONCLUSIONS: Our results imply that L. salivarius WB21 may be useful for controlling dental caries, periodontitis, and oral malodor. In addition, the effects of L. salivarius WB21 on periodontitis and oral malodor may be synergistically enhanced by use in combination with EGCg.

Chemical composition, cytotoxic effect and antimicrobial activity of Stachys koelzii Rech.f. essential oil against periodontal pathogen Prevotella intermedia.

Prevotella intermedia is associated with periodontal diseases and endodontic infections. Periodontitis can be suppressed by utilizing the antiseptics, which target the infectious bacteria. The member of Stachys sp. has been used traditionally in the form of decoction or infusion for management of infectious diseases. The subject of this article was to evaluate the chemical composition, antimicrobial and cytotoxic effect of Stachys koelzii essential oil and its main components against Prevotella intermedia. GC-FID and GC-MS analysis were used to determine the chemical composition. The antimicrobial effects of S. koelzii essential oil was evaluated by micro-broth dilution assay. Time kill curve assays, leakage of cytoplasmic materials and anti-biofilm effects were determined. Its cytotoxic effect was evaluated by MTT assay. Essential oil with main components of α-pinene, trans-caryophyllene and 1,8-cineole inhibited P. intermedia with MIC and MBC values of 0.1 and 0.2 mg/mL. Its biofilm formation was higher than α-pinene, followed by trans-caryophyllene and 1,8-cineole. Essential oil and its main components increased the leakage of cytoplasmic components. Essential oil showed cytotoxic effect on HeLa cell lines with IC50 0.06 mg/mL. The cytotoxic effect of α-pinene on healthy cell lines was higher than essential oil. S. koelzii essential oil can be used in mouthwash formulations and its efficacy should be evaluated in large clinical studies.

Antibacterial Activity of Homeopathic Medications Lycopodium clavatum and Arsenicum album Against Periodontal Bacteria / Evaluación antibacteriana de los medicamentos homeopáticos sobre bacterias periodontales

Abstract There are several controversies regarding the efficacy of homeopathic substances; however, these remedies are used in many countries for the treatment of various pathological conditions. The purpose of this study was to evaluate the in vitro antibacterial activity of two homeopathic tinctures Arsenicum album (mineral extract) and Lycopodium clavatum (plant extract) on the periodontal bacteria Actinomyces israelii, Streptococcus sanguinis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans and Phorphyromonas gingivalis (P. gingivalis). Materials and methods: Equal numbers of bacteria were seeded on agar plates containing enriched media with the homeopathic solutions at 1dH and 1cH dilutions. After 7 days of incubation under anaerobic conditions, colony forming units (CFUs) were counted. The antibacterial effect was calculated based on the total number of CFUs observed on non-tincture containing agar, and on the tincture containing plates. Results: No visible growth of any of the strains was observed on the plates containing Arsenicum album at any of the dilutions tested. In contrast, when Lycopodium clavatum at 1cH dilution was tested, only P. gingivalis was susceptible to this compound. Conclusions: The results suggest that the mineral extract tincture had a greater antibacterial activity than the plant extract tincture, also Lycopodium clavatum preparation could be an effective inhibitor of periodontal pathogens bacteria such as P. gingivalis.

Resumen Se necesita un mayor número de estudios in vitro e in vivo para validar estos resultados.

Comparative evaluation of the antimicrobial susceptibility and cytotoxicity of husk extract of Cocos nucifera and chlorhexidine as irrigating solutions against Enterococcus Faecalis, Prevotella Intermedia and Porphyromonas Gingivalis - An in-vitro study.

AIM AND BACKGROUND: The aim of the present study is to evaluate and compare the antimicrobial susceptibility and cytotoxicity of Cocos nucifera and chlorhexidine (CHX) as irrigating solutions against Enterococcus faecalis, Prevotella intermedia, and Porphyromonas gingivalis. MATERIALS AND METHODS: The ethanolic extract of husk of C. nucifera was prepared. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined using the serial broth dilution method and its cytotoxicity was evaluated against human periodontal fibroblasts using 3-(4,5-dimethyl-thiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay. Antibacterial susceptibility for two irrigating solutions, namely 2% CHX gluconate irrigant (Group I) and 1.5% C. nucifera husk irrigant (Group II), was tested against P. gingivalis, P. intermedia, and E. faecalis. RESULTS: The MIC and MBC of C. nucifera husk extract for P. gingivalis were 468.75 µg/ml and 1562.5 µg/ml, for P. intermedia were 48.8 µg/ml and 1875 µg/ml, and for E. faecalis were 1562.5 µg/ml and 3750 µg/ml, respectively. The extract was nontoxic to the human periodontal fibroblast. Both the materials have shown similar antibacterial susceptibility and no difference was observed at baseline, 10, 30, and 60 min using two-way repeated measures of ANOVA. However, a statistically significant difference was observed between different time points for P. gingivalis and P. intermedia using Bonferroni multiple comparison test (f = 826.1390, P ≤ 0.05). CONCLUSION: 1.5% of ethanolic husk extract of C. nucifera has a significant antibacterial action against polymicrobial dental biofilm and its activity is comparable to that of 2% CHX which validates its use as a future irrigating solution for overcoming bacterial resistance with synthetic agents.

Components in Lentinus edodes mushroom with anti-biofilm activity directed against bacteria involved in caries and gingivitis.

The present study investigated the compounds present in the low molecular mass fraction of Lentinus edodes mushroom (shiitake) extract and their anti-virulence activity against oral pathogens (reference and clinical Streptococcus mutans, Actinomyces naeslundii, and Prevotella intermedia strains). Oxalic, succinic, and quinic acids, and adenine, inosine, and uridine were identified by HPLC-DAD-ESI-MS/MS. Their anti-biofilm production and preformed biofilm disaggregation activities were studied using commercial standard compounds at different concentrations. As regards S. mutans, the highest activity was shown by adenine at 5 mg mL-1 both in the biofilm inhibition (BI 50%) and biofilm disaggregation tests (BD 20%). Considering A. naeslundii, BI values close to 80% were registered for oxalic acid at 1 mg mL-1 and 2 mg mL-1 and BD 50% for quinic acid at 3 mg mL-1. A weaker activity was found against P. intermedia. Furthermore, different mixtures of the commercial standards were tested showing that the activity of a compound can be strongly and sometimes negatively affected by the presence of the other compounds.

D-Cateslytin, a new antimicrobial peptide with therapeutic potential.

The rise of antimicrobial resistant microorganisms constitutes an increasingly serious threat to global public health. As a consequence, the efficacy of conventional antimicrobials is rapidly declining, threatening the ability of healthcare professionals to cure common infections. Over the last two decades host defense peptides have been identified as an attractive source of new antimicrobials. In the present study, we characterized the antibacterial and mechanistic properties of D-Cateslytin (D-Ctl), a new epipeptide derived from L-Cateslytin, where all L-amino acids were replaced by D-amino acids. We demonstrated that D-Ctl emerges as a potent, safe and robust peptide antimicrobial with undetectable susceptibility to resistance. Using Escherichia coli as a model, we reveal that D-Ctl targets the bacterial cell wall leading to the permeabilization of the membrane and the death of the bacteria. Overall, D-Ctl offers many assets that make it an attractive candidate for the biopharmaceutical development of new antimicrobials either as a single therapy or as a combination therapy as D-Ctl also has the remarkable property to potentiate several antimicrobials of reference such as cefotaxime, amoxicillin and methicillin.

Microbiologic Response to Periodontal Therapy and Multivariable Prediction of Clinical Outcome.

BACKGROUND: This study assesses the microbiologic effects of a two-phase antimicrobial periodontal therapy and tested microbiologic, clinical, and biologic markers as prognostic indicators for clinical success. METHODS: Eighty patients with chronic or aggressive periodontitis received periodontal treatment supplemented with 375 mg amoxicillin plus 500 mg metronidazole, three times daily for 7 days. In group A, antibiotics were given during the first non-surgical phase (T1); in group B, antibiotics were given during the second surgical phase (T2). Six microorganisms, group assignment, demographic and clinical variables, peak values of 15 cytokines, and nine acute-phase proteins in serum were evaluated as potential predictors of at least one site with probing depth (PD) >4 mm and bleeding on probing (BOP) at 12 months post-therapy. RESULTS: T1 decreased the counts of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia (Pi), and Treponema denticola significantly more in group A than group B. Aggregatibacter actinomycetemcomitans and Parvimonas micra (Pm) showed a significant decrease only if the treatment was supplemented with antibiotics, i.e., T1 in group A, or T2 in group B. After T2, differences between groups were no longer significant. A multivariable model including four parameters revealed a predictive value of Pm (odds ratio [OR] = 4.38, P = 0.02) and Pi (OR = 3.44, P = 0.049) and yielded moderate accuracy for predicting the treatment outcome (area under the curve = 0.72). Host-derived factors and treatment sequence were not significantly associated with the outcome. CONCLUSIONS: Long-term microbiologic outcomes of periodontal therapy with adjunctive antibiotics either in T1 or T2 were similar. Detection of Pm before therapy was a predictor for persistence of sites with PD >4 mm and BOP at 12 months post-treatment.

Antimicrobial Effects of Mastic Extract Against Oral and Periodontal Pathogens.

BACKGROUND: Various antimicrobial agents are widely used in the therapy of oral inflammatory diseases. However, their side effects and the appearance of drug resistance justify research on natural antimicrobial agents to target oral pathogens that are safe for the host. In the present study, antimicrobial properties of mastic extract on commensal and pathogenic oral bacteria, as well as its possible cytotoxic effect toward cells of epithelial and mesenchymal origin, were evaluated and compared with the common antimicrobial agents hydrogen peroxide (H2O2) and chlorhexidine digluconate (CHX). METHODS: Oral and periodontal pathogens (Porphyromonas gingivalis, Streptococcus mutans [Sm], Streptococcus oralis, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, and Prevotella nigrescens) were treated with different concentrations of mastic extract, 3% H2O2, and 0.2% CHX, and evaluated with an agar diffusion test. The cytotoxic effect of mastic extract was tested on four cell lines of epithelial and mesenchymal origin (HaCaT, SaOS-2, MC3T3-E1, periodontal ligament [PDL] cells) by neutral red and 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assay. RESULTS: Mastic extract led to significantly (P ≤0.016) increased inhibition of the tested periodontal pathogens compared with H2O2. No effect of mastic extract was observed on Sm. Mastic extract showed beneficial effects on cell viability because viability values of tested cells were significantly (P ≤0.016) lower for cells treated with CHX and H2O2 compared with mastic extract-treated cells after stimulation for 2, 4, and 6 hours. CONCLUSION: The present data demonstrate mastic extract's inhibition of periodontal pathogens, as well as beneficial effects on cell viability, compared with H2О2, suggesting that it could be considered an alternative antibacterial agent in the prevention of periodontal disease.

In vitro Resistance Testing of Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia to Triclosan.

AIM: To determine the sensitivity of Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia to triclosan, and determine if these bacteria develop resistance to triclosan upon prolonged exposure. MATERIALS AND METHODS: Susceptibility to triclosan was tested against three periodontal pathogens P. gingivalis, P. intermedia, and T. forsythia. Escherichia coli strains sensitive and resistant to triclosan were used as biological controls to confirm the efficacy of triclosan in the assays. Agar plates were prepared locally with vitamin K and hemin-supplemented medium. RESULTS: Porphyromonas gingivalis and P. intermedia did not grow on plates containing ≥ 2 µg/ml triclosan, while T. forsythia did not grow on ≥ 1.66 µg/ml. Colonies of P. intermedia resistant to triclosan developed after prolonged incubation at 2 µg/ml, but this resistance disappeared during subculture in the absence of triclosan. CONCLUSION: No significant resistance to triclosan was detected for these species. CLINICAL SIGNIFICANCE: Dental products containing triclosan can be beneficial in controlling periodontal disease.

Antimicrobial effects of citrus sinensis peel extracts against periodontopathic bacteria: an in vitro study.

BACKGROUND: Use of plant extracts and phytochemicals with known antimicrobial properties may have great significance in therapeutic treatments. OBJECTIVE: To assess the in vitro antimicrobial potential and also determine the minimum inhibitory concentration (MIC) of Citrus sinensis peel extracts with a view of searching a novel extract as a remedy for periodontal pathogens. MATERIALS AND METHODS: Aqueous and ethanol (cold and hot) extracts prepared from peel of Citrus sinensis were screened for in vitro antimicrobial activity against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia, using agar well diffusion method. The lowest concentration of every extract considered as the minimal inhibitory concentration (MIC) values were determined for both test organisms. Confidence level and level of significance were set at 95% and 5% respectively. RESULTS: Prevotella intermedia and Porphyromonas gingivalis were resistant to aqueous extracts while Aggregatibacter actinomycetemcomitans was inhibited at very high cncentrations. Hot ethanolic extracts showed significantly higher zone of inhibition than cold ethanolic extract. Minimum inhibitory concentration of hot and cold ethanolic extracts of Citrus sinensis peel ranged between 12-15 mg/ml against all three periodontal pathogens. CONCLUSIONS: Both extracts were found sensitive and contain compounds with therapeutic potential. Nevertheless, clinical trials on the effect of these plants are essential before advocating large-scale therapy.

Antibiofilm efficacy of photosensitizer-functionalized bioactive nanoparticles on multispecies biofilm.

INTRODUCTION: Newer disinfection strategies based on antibacterial nanoparticles and photodynamic therapy (PDT) aim to eliminate residual biofilm bacteria during root canal treatment. The aim of the current study was to test the newly developed rose bengal-functionalized chitosan nanoparticles (CSRBnps) for their interaction/uptake with monospecies bacteria/biofilm and assess their antibiofilm efficacy on a multispecies biofilm model in vitro. METHODS: The interaction of CSRBnps with bacterial cells was conducted using atomic force microscopy. Their membrane-damaging effect was determined by measuring the absorbance at 260 nm (OD260nm) using Enterococcus faecalis. The penetration of CSRBnps into E. faecalis biofilms was evaluated using confocal laser scanning microscopy (CLSM). Multispecies biofilms of Streptococcus oralis, Prevotella intermedia, and Actinomyces naeslundii were grown on dentin sections for 21 days to assess the antibiofilm efficacy. The biofilms were subjected to PDT (60 J/cm(2)) using CSRBnps and rose bengal. The treated/untreated biofilms were examined under scanning electron microscopy and CLSM. RESULTS: The CSRBnps synthesized were 60 ± 20 nm and showed absorption spectra similar to rose bengal. Atomic force microscopy showed adherence of CSRBnps to bacteria, roughening of cell surface, and cell disruption after PDT. CSRBnp treatment resulted in significantly increased bacterial membrane damage (P < .05). CSRBnps exhibited deeper penetration into the biofilm structure. Scanning electron microscopy and CLSM confirmed the complete disruption of multispecies biofilm with a reduction in viable bacteria and biofilm thickness (P < .05). CONCLUSIONS: These novel photosensitizer functionalized bioactive nanoparticles with increased affinity to bacterial cell membrane, higher penetration into biofilm structure, and enhanced ability to eliminate clinically relevant multispecies bacterial biofilm present a potential antibiofilm agent for root canal disinfection.

[Effects of cetylpyridinium chloride buccal tablets on halitosis induced by oral conditions].

OBJECTIVE: To investigate the effect of cetylpyridinium chloride buccal tablets on halitosis induced by oral conditions. METHODS: With Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum as the testing bacteria, the minimal inhibitory concentration (MIC) of cetylpyridinium chloride buccal tablets was determined using minute amount serial dilution test. The production of volatile sulfur compounds (VSCs) was measured using sulfide detector halimeter in the anaerobic bacteria culture at 4 and 8 h after addition of the tablets. The effect of the tablets in suppressing odor production by mouth-borne halitosis bacteria was assessed using cysteine challenge test in healthy volunteers, and the effectiveness was evaluated by measuring the reduction in VSCs production and the duration of the effect. RESULTS: Cetylpyridinium chloride buccal tablets inhibited the growth of all the 3 bacteria. The tablets obviously inhibited VSCs production by the 3 bacteria with a effect similar to chlorhexidine. Compared with distilled water gargle, the buccal tablets significantly reduced cysteine-induced VSCs production level in the healthy volunteers (P<0.05), and the effect lasted for 230 min. CONCLUSION: Cetylpyridinium chloride tablets can obviously suppress bacteria responsible for oral halitosis and produce good effects in the treatment of halitosis induced by oral conditions.

Predicting the influence of multiple components on microbial inhibition using a logistic response model--a novel approach.

BACKGROUND: There are several synergistic methods available. However, there is a vast discrepancy in the interpretation of the synergistic results. Also, these synergistic methods do not assess the influence the tested components (drugs, plant and natural extracts), have upon one another, when more than two components are combined. METHODS: A modified checkerboard method was used to evaluate the synergistic potential of Heteropyxis natalensis, Melaleuca alternifolia, Mentha piperita and the green tea extract known as TEAVIGO™. The synergistic combination was tested against the oral pathogens, Streptococcus mutans, Prevotella intermedia and Candida albicans. Inhibition data obtained from the checkerboard method, in the form of binary code, was used to compute a logistic response model with statistically significant results (p < 0.05). This information was used to construct a novel predictive inhibition model. RESULTS: Based on the predictive inhibition model for each microorganism, the oral pathogens tested were successfully inhibited (at 100% probability) with their respective synergistic combinations. The predictive inhibition model also provided information on the influence that different components have upon one another, and on the overall probability of inhibition. CONCLUSIONS: Using the logistic response model negates the need to 'calculate' synergism as the results are statistically significant. In successfully determining the influence multiple components have upon one another and their effect on microbial inhibition, a novel predictive model was established. This ability to screen multiple components may have far reaching effects in ethnopharmacology, agriculture and pharmaceuticals.

Inhibitory activity of green tea (Camellia sinensis) extract on some clinically isolated cariogenic and periodontopathic bacteria.

OBJECTIVE: To determine the in vitro inhibitory activity of green tea extract on some clinically isolated cariogenic and periodontopathic bacteria. MATERIALS AND METHODS: Twenty strains of each of Streptococcusmutans, Aggregatibacteractinomycetemcomitans, Porphyromonasgingivalis, and Prevotellaintermedia were isolated from carious teeth and periodontal pockets of patients with dental caries and periodontal diseases. Green tea extract was prepared by aqueous extraction method and diluted from 50 to 1.56 mg/ml. Standard techniques of agar disk diffusion and broth microdilution assays were applied for qualitative and quantitative determinations of antibacterial activity of green tea extract on each isolates. RESULTS: All clinical isolates of S. mutans (100%) were sensitive to green tea extract at concentrations 6.25, 12.5, 25, and 50 mg/ml producing inhibition zones ranging from 10 to 38 mm. All periodontopathic isolates (A. actinomycetemcomitans, n = 20, P. intermedia, n = 20, and P. gingivalis, n = 20) (100%) tested were sensitive to 12.5, 25, and 50 mg/ml of this extract. The minimal inhibitory concentration of green tea extract for S. mutans was 3.28 ± 0.7 mg/ml and for A. actinomycetemcomitans 6.25, for P. gingivalis and P. intermedia 12.5 mg/ml. CONCLUSIONS: Our findings showed that green tea extract exhibited strong antibacterial activity on S. mutans,A. actinomycetemcomitans,P. gingivalis and P. intermedia and therefore may be used in mouthwashes or dentifrices for prevention of dental caries and periodontal diseases.

Identification of organic acids in Cichorium intybus inhibiting virulence-related properties of oral pathogenic bacteria.

The low molecular mass (LMM) extract of Cichorium intybus var. silvestre (red chicory) has been shown to inhibit virulence-linked properties of oral pathogens including Streptococcus mutans, Actinomyces naeslundii and Prevotella intermedia. In the present study HPLC-DAD-ESI/MS(2) was used to investigate the compounds contained in this extract for their anti-virulence activity. The extract contained a number of components, including oxalic, succinic, shikimic and quinic acids, which interfere with the growth and virulence traits (i.e., biofilm formation, adherence to epithelial cells and hydroxyapatite) of oral pathogens involved in gingivitis and tooth decay. Succinic and quinic acid seem to be the most potent, mainly by interfering with the ability of oral pathogens to form biofilms (either through inhibition of their development or promotion of their disruption). Our findings suggest that one or more of these compounds may modulate plaque formation in vivo, which is a prerequisite for the development of both caries and gingivitis.

Antibacterial effects of blackberry extract target periodontopathogens.

BACKGROUND AND OBJECTIVE: Antimicrobial agents provide valuable adjunctive therapy for the prevention and the control of oral diseases. Limitations in their prolonged use have stimulated the search for new, naturally occurring agents with more specific activity and fewer adverse effects. Here we sought to determine the antibacterial properties of blackberry extract (BBE) in vitro against oral bacterial commensals and periodontopathogens. MATERIAL AND METHODS: The effects of whole and fractionated BBE on the metabolism of 10 different oral bacteria were evaluated using the colorimetric water-soluble tetrazolium-1 assay. The bactericidal effects of whole BBE against Fusobacterium nucleatum were determined by quantitating the numbers of colony-forming units (CFUs). Cytotoxicity was determined in oral epithelial (OKF6) cells. RESULTS: BBE at 350-1400 µg/mL reduced the metabolic activity of Porphyromonas gingivalis, F. nucleatum and Streptococcus mutans. The reduced metabolic activity observed for F. nucleatum corresponded to a reduction in the numbers of CFUs following exposure to BBE for as little as 1 h, indicative of its bactericidal properties. An anthocyanin-enriched fraction of BBE reduced the metabolic activity of F. nucleatum, but not of P. gingivalis or S. mutans, suggesting the contribution of species-specific agents in the whole BBE. Oral epithelial cell viability was not reduced following exposure to whole BBE (2.24-1400 µg/mL) for ≤ 6 h. CONCLUSION: BBE alters the metabolic activity of oral periodontopathogens while demonstrating a minimal effect on commensals. The specific antibacterial properties of BBE shown in this study, along with its previously demonstrated anti-inflammatory and antiviral properties, make this natural extract a promising target as an adjunct for prevention and/or complementary therapy of periodontal infections.

A double-blind randomized placebo-controlled study on the clinical and microbial effects of an essential oil mouth rinse used by patients in supportive periodontal care.

AIM: This 3-month double-blind randomized placebo-controlled study evaluated the clinical and microbial effects of an essential oil mouth rinse used as an adjunct to mechanical plaque control by patients in supportive periodontal care. MATERIAL AND METHODS: Fifty patients were randomly allocated to an essential oil group (Listerine(®) Coolmint; Johnson & Johnson, New Brunswick, NJ, USA) or placebo group to rinse twice per day as an adjunct to mechanical plaque control. At baseline and after 3 months, plaque index (PI), gingivitis index (GI), probing pocket depth, bleeding on probing (BoP) and clinical attachment level were registered. Subgingival plaque samples were collected for the detection and quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Micromonas micros, Prevotella intermedia, Fusobacterium genus and Streptococcus mutans by means of real-time PCR (qPCR). Patient's compliance, satisfaction and side effects were registered. RESULTS: Twenty-three patients in the essential oil group (mean age: 57) and 21 in the placebo group (mean age: 55) with acceptable oral hygiene at intake (mean PI <1.5 on a scale of 5) adhered to the study protocol. Gingivitis index, PI and BoP significantly reduced over time (P ≤ 0.029); however, between group analyses revealed no significant differences. There was no significant change over time neither in detection frequency nor load for any of the microbiota. Daily rinsing with an essential oil rinse was found safe and perceived beneficial by the patients. CONCLUSION: Patients in supportive periodontal care who are fairly compliant with oral hygiene may not benefit from additional mouth rinsing using an essential oil solution.

Prevalence of ß-lactamase-producing bacteria in human periodontitis.

BACKGROUND AND OBJECTIVE: Beta-lactam antibiotics prescribed in periodontal therapy are vulnerable to degradation by bacterial ß-lactamases. This study evaluated the occurrence of ß-lactamase-positive subgingival bacteria in chronic periodontitis subjects of USA origin, and assessed their in vitro resistance to metronidazole at a breakpoint concentration of 4 µg/mL. MATERIAL AND METHODS: Subgingival plaque specimens from deep periodontal pockets with bleeding on probing were removed from 564 adults with severe chronic periodontitis before treatment. The samples were transported in VMGA III and then plated onto: (i) nonselective enriched Brucella blood agar (EBBA) and incubated anaerobically for 7 d; and (ii) selective trypticase soy-bacitracin-vancomycin (TSBV) and incubated for 3 d in air + 5% CO2 . At the end of the incubation periods, the bacterial test species were identified and quantified. Specimen dilutions were also plated onto EBBA plates supplemented with 2 µg/mL of amoxicillin, a combination of 2 µg/mL of amoxicillin plus 2 µg/mL of the ß-lactamase inhibitor clavulanic acid, or 4 µg/mL of metronidazole, followed by anaerobic incubation for 7 d. Bacterial test species presumptively positive for ß-lactamase production were identified by growth on EBBA primary isolation plates supplemented with amoxicillin alone and no growth on EBBA primary isolation plates containing both amoxicillin plus clavulanic acid. A subset of such isolates was subjected to nitrocefin-based chromogenic disk testing to confirm the presence of ß-lactamase activity. In vitro resistance to 4 µg/mL of metronidazole was noted when growth of test species occurred on metronidazole-supplemented EBBA culture plates. RESULTS: Two-hundred and ninety-four (52.1%) of the study subjects yielded ß-lactamase-producing subgingival bacterial test species, with Prevotella intermedia/nigrescens, Fusobacterium nucleatum and other Prevotella species most frequently identified as ß-lactamase-producing organisms. Of the ß-lactamase-producing bacterial test species strains recovered, 98.9% were susceptible in vitro to metronidazole at 4 µg/mL. CONCLUSION: The occurrence of ß-lactamase-positive subgingival bacterial species in more than half of the subjects with severe chronic periodontitis raises questions about the therapeutic potential of single-drug regimens with ß-lactam antibiotics in periodontal therapy. The in vitro effectiveness of metronidazole against nearly all recovered ß-lactamase-producing subgingival bacterial species further supports clinical periodontitis treatment strategies involving the combination of systemic amoxicillin plus metronidazole.

Efficacy of berberine, an antimicrobial plant alkaloid, as an endodontic irrigant against a mixed-culture biofilm in an in vitro tooth model.

INTRODUCTION: Berberine, a plant alkaloid isolated from many medicinal plants, has shown antimicrobial activity against selected oral pathogens. The purpose of this investigation was to evaluate the antimicrobial efficacy of berberine solution against selected endodontic pathogens using a multispecies biofilm tooth model. METHODS: The bacterial species used in the multispecies biofilm tooth model were Fusobacterium nucleatum, Enterococcus faecalis, and Prevotella intermedia. Extracted human anterior teeth were collected and standardized to a length of 14.0 mm. Teeth were cultured in Schaedler broth with the 3 test bacteria strains for 21 days and then randomly assigned to 6 treatment groups (ie, sterile saline, 5.25% NaOCl, 2% chlorhexidine [CHX], 1% CHX, 2 mg/mL berberine, and 1 mg/mL berberine plus 1% CHX). The teeth were instrumented to size 35/.06 and irrigated with 6 mL irrigant for 2 minutes. Surviving bacteria were sampled before and after instrumentation. Data were analyzed using analysis of variance (P < .05) followed by the Scheffé test. RESULTS: The minimal inhibitory concentration of berberine against F. nucleatum, P. intermedia, and E. faecalis was 31.25 µg/mL, 3.8 µg/mL, and 500 µg/mL, respectively. Instrumentation and irrigation resulted in 99% bacterial reduction in all groups. All tested solutions resulted in a statistically significant reduction in bacteria when compared with the saline control. When used alone, berberine (2 mg/mL) was less effective than the other test irrigants. However, when combined with 1% CHX, berberine (2 mg/mL) was comparable in bactericidal activity with 5.25% NaOCl, 2% CHX, and 1% CHX (Table 2). CONCLUSIONS: Berberine was more effective than saline as an endodontic irrigant against selected endodontic pathogens in vitro and, when combined with CHX, was comparable with NaOCl in its bactericidal efficacy.

In vitro evaluation of MTAD and nisin in combination against common pathogens associated with root canal infection.

INTRODUCTION: Many pathogenic microorganisms were found in an infected root canal. The object of this study was to evaluate the effect of MTAD in combination with nisin on the pathogens associated with root canal infection. METHODS: The survival rates of 9 pathogenic bacteria were determined after 1-, 5-, and 10-minute treatment with MTAD, MTAN (substitution of doxycycline with nisin), and MTADN (nisin in combination with doxycycline). The survival rates of Enterococcus faecalis in the starvation phase and pretreatment alkalization as well as in the normal physiological state under MTAD, MTAN, and MTADN challenge for 1, 5, and 10 minutes were evaluated and compared. Furthermore, scanning electron microscopy was used to observe the morphologic modification of Actinomyces naeslundii, Lactobacillus paracasei, and Porphyromonas gingivalis after MTAD and MTADN treatment. RESULTS: L. fermenti, L. paracasei, A. viscosus, A. naeslundii, Streptococcus gordonii, and Peptostreptococcus were more sensitive to MTADN and MTAN than to MTAD. MTAD, MTAN, and MTADN showed a rapid antibacterial effect on P. gingivalis, Prevotella intermedia, and Fusobacterium nucleatum. Enterococcus faecalis in the stress state was as sensitive to MTAD, MTAN, and MTADN as the control E. faecalis. Furthermore, in the observation of scanning electron microscopy, the membranes in A. naeslundii and L. paracasei presented significant rupture, and P. gingivalis did not exhibit significant damage after MTADN treatment. CONCLUSIONS: MTAD in combination with nisin improved antibacterial efficacy against pathogens, especially for some gram-positive bacteria associated with persistent intracanal infection. Therefore, the combination had the potential to be used as an effective intracanal irrigation.