Efficacy of a mouthwash containing ε-poly-L-lysine, funme peptides and domiphen in reducing halitosis and supragingival plaque: a randomized clinical trial

OBJECTIVE

To evaluate the antibacterial effectiveness of a combination of ε-poly-L-lysine (ε-PL), funme peptide (FP) as well as domiphen against oral pathogens, and assess the efficacy of a BOP® mouthwash supplemented with this combination in reducing halitosis and supragingival plaque in a clinical trial.

MATERIALS AND METHODS

The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the compound against Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans were determined by the gradient dilution method. Subsequently, the CCK-8 assay was used to detect the toxicity of mouthwash on human gingival fibroblastst, and the effectiveness in reducing halitosis and supragingival plaque of the mouthwash supplemented with the combination was analyzed by a randomized, double-blind, parallel-controlled clinical trial.

RESULTS

The combination exhibited significant inhibitory effects on tested oral pathogens with the MIC < 1.56% (v/v) and the MBC < 3.13% (v/v), and the mouthwash containing this combination did not inhibit the viability of human gingival fibroblasts at the test concentrations. The clinical trial showed that the test group displayed notably lower volatile sulfur compounds (VSCs) at 0, 10, 24 h, and 7 d post-mouthwash (P < 0.05), compared with the baseline. After 7 days, the VSC levels of the and control groups were reduced by 50.27% and 32.12%, respectively, and notably cutting severe halitosis by 57.03% in the test group. Additionally, the Plaque Index (PLI) of the test and control group decreased by 54.55% and 8.38%, respectively, and there was a significant difference in PLI between the two groups after 7 days (P < 0.01).

CONCLUSIONS

The combination of ε-PL, FP and domiphen demonstrated potent inhibitory and bactericidal effects against the tested oral pathogens, and the newly formulated mouthwash added with the combination exhibited anti-dental plaque and anti-halitosis properties in a clinical trial and was safe.

TRIAL REGISTRATION

The randomized controlled clinical trial was registered on Chinese Clinical Trial Registry (No. ChiCTR2300073816, Date: 21/07/2023).

Microbiological Effects of Sodium Hypochlorite/-Amino Acids and Cross-linked Hyaluronic Acid Adjunctive to Non-surgical Periodontal Treatment

PURPOSE

To investigate the microbiological outcomes obtained with either subgingival debridement (SD) in conjunction with a gel containing sodium hypochlorite and amino acids followed by subsequent application of a cross-linked hyaluronic acid gel (xHyA) gel, or with SD alone.

MATERIALS AND METHODS

Forty-eight patients diagnosed with stages II-III (grades A/B) generalised periodontitis were randomly treated with either SD (control) or SD plus adjunctive sodium hypochlorite/amino acids and xHyA gel (test). Subgingival plaque samples were collected from the deepest site per quadrant in each patient at baseline and after 3 and 6 months. Pooled sample analysis was performed using a multiplex polymerase chain reaction (PCR)-based method for the identification of detection frequencies and changes in numbers of the following bacteria: Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Tannerella forsythia (T.f), Treponema denticola (T.d), and Prevotella intermedia (P.i).

RESULTS

In terms of detection frequency, in the test group, statistically significant reductions were found for P.g, T.f, T.d and P.i (p < 0.05) after 6 months. In the control group, the detection frequencies of all investigated bacterial species at 6 months were comparable to the baseline values (p > 0.05). The comparison of the test and control groups revealed statistically significant differences in detection frequency for P.g (p = 0.034), T.d (p < 0.01) and P.i (p = 0.02) after 6 months, favouring the test group. Regarding reduction in detection frequency scores, at 6 months, statistically significant differences in favour of the test group were observed for all investigated bacterial species: A.a (p = 0.028), P.g (p = 0.028), T.f (p = 0.004), T.d (p <0.001), and P.i (p = 0.003).

CONCLUSIONS

The present microbiological results, which are related to short-term outcomes up to 6 months post-treatment, support the adjunctive subgingival application of sodium hypochlorite/amino acids and xHyA to subgingival debridement in the treatment of periodontitis.

An in vitro dynamic bioreactor model for evaluating antimicrobial effectiveness on periodontal polymicrobial biofilms: a proof-of-concept study

BACKGROUND

The aim of this study was to investigate an in vitro dynamic bioreactor model by evaluating the antimicrobial effect of clinically relevant amoxicillin doses on polymicrobial microcosm biofilms derived from subgingival plaque.

METHODS

Biofilms from pooled subgingival plaque were grown for 108  hours in control and experimental dynamic biofilm reactors. Amoxicillin was subsequently infused into the experimental reactor to simulate the pharmacokinetic profile of a standard 500 mg thrice-daily dosing regimen over 5 days and biofilms were assessed by live/dead staining, scanning electron microscopy, and quantitative polymerase chain reaction.

RESULTS

Following establishment of the oral microcosm biofilms, confocal imaging analysis showed a significant increase in dead bacteria at 8 hours (p = 0.0095), 48 hours (p = 0.0070), 96 hours (p = 0.0140), and 120 hours (p < 0.0001) in the amoxicillin-treated biofilms compared to the control biofilms. Nevertheless, viable bacteria remained in the center of the biofilm at all timepoints. Significant reductions/elimination in Campylobacter rectus, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, and Peptostreptococcus anaerobius was observed among the amoxicillin-treated biofilms at the 96 and 120 hour timepoints.

CONCLUSION

A novel in vitro dynamic model of oral microcosm biofilms was effective in modeling the antimicrobial effect of a pharmacokinetically simulated clinically relevant dose of amoxicillin.

Weissella cibaria CMU exerts an anti‑inflammatory effect by inhibiting Aggregatibacter actinomycetemcomitans‑induced NF‑κB activation in macrophages

Periodontitis is a chronic inflammatory disease caused by various periodontal pathogens. Weissella cibaria CMU (oraCMU) is a probiotic that promotes oral health. However, its anti‑inflammatory effects against periodontal pathogens have not yet been investigated. The present study evaluated the anti‑inflammatory effects of live oraCMU against stimulation with the formalin‑inactivated periodontal pathogen Aggregatibacter actinomycetemcomitans in RAW 264.7 macrophages. Cell viability was analyzed by the MTS assay in a dose‑dependent manner (at multiplicities of infection of 0.1, 1, 10, 100 and 1,000). Nitric oxide (NO) was monitored using the Griess test. The mRNA expression of proinflammatory cytokines such as interleukin (IL)1β and IL6 was assessed by reverse transcription‑quantitative PCR. Western blotting was used to examine the effects of oraCMU on the phosphorylation of NF‑κB inhibitor α (IκBα) and IκBα kinase (IKK), the nuclear translocation of the NF‑κB subunit p65 and the expression of inducible NO synthase (iNOS). Live oraCMU had no cytotoxic effects on RAW 264.7 macrophages. In A. actinomycetemcomitans‑stimulated RAW 264.7 macrophages, oraCMU reduced NO production by suppressing iNOS expression and downregulating the mRNA expression of proinflammatory cytokines in a dose‑dependent manner. IKK phosphorylation and IκBα degradation were dose‑dependently inhibited by oraCMU and the nuclear translocation of p65 via the canonical NF‑κB pathway was simultaneously reduced. The results indicated that oraCMU possessed anti‑inflammatory activity associated with the inhibition of NF‑κB signal activation in response to periodontal pathogens. This suggests that oraCMU is a beneficial anti‑inflammatory probiotic that can aid in the maintenance of oral health.

Efficacy of antimicrobial photodynamic therapy for elimination of Aggregatibacter actinomycetemcomitans biofilm on Laser-Lok titanium discs

BACKGROUND

Antimicrobial Photodynamic therapy (aPDT) is a novel modality suggested for treatment of peri-implantitis. This study aimed to assess the effect of aPDT with toluidine blue (TBO) and indocyanine green (ICG) and 635 nm and 808 nm diode laser on Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) biofilm formed on Laser-Lok titanium discs.

MATERIALS AND METHODS

Eighty sterile Laser-Lok titanium discs were inoculated with A. actinomycetemcomitans to form biofilm and were randomly divided into 8 groups (n = 10) of control, chlorhexidine (CHX), TBO, ICG, 635 nm diode laser with 220 mW power, 808 nm diode laser with 250 mW power, 100 μg/mL TBO+635 nm diode laser and ICG+808 nm diode laser. Number of colony forming units (CFUs) on the surface of each disc was counted after the intervention. Data were analyzed using the Kruskal-Wallis test.

RESULTS

Significant differences were noted in colony count among the eight groups after the intervention (P = 0.001). Pairwise comparisons with adjusted P value test showed that aPDT with TBO+635 nm laser and ICG+808 nm laser caused significant reduction of bacterial biofilm compared to the control group (P = 0.0001). TBO alone caused significant reduction of biofilm compared to the control group (P = 0.004). No other significant differences were noted (P > 0.05).

CONCLUSION

Within the limitations of this study, the results showed that aPDT is a potential modality for decontamination of implant surface and reduction of A. actinomycetemcomitans biofilm in vitro. In this study, aPDT with TBO+635 nm diode laser and ICG+808 nm diode laser decreased the bacterial load on titanium discs.

Antimicrobial activity of NO-releasing compounds against periodontal pathogens

This study describes the successful synthesis of nitric oxide (NO)-releasing compounds with biodegradable and injectable properties and demonstrates that the kinetics of NO release vary according to the type of NO donor. The antimicrobial activity of NO-releasing compounds against three common periodontal pathogens, i.e., Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Actinomyces israelii, was investigated using a susceptibility assay. Human gingival fibroblasts were treated with NO-releasing compounds at the minimum concentrations required for bacterial growth and cytotoxicity was evaluated using the MTT cell proliferation assay. Our results suggest that NO-releasing compounds can be used topically to treat both gram-negative and gram-positive periodontal pathogens. Comparison of the antimicrobial activity and cytotoxicity assay results between the NO-releasing compounds revealed that an NO donor comprising a macromolecule without surface charge, a lower instantaneous NO concentration, and an adequate supply of NO were associated with a strong bactericidal effect and low cytotoxicity. NO-releasing compounds with these properties may be suitable for treatment of periodontitis.

Effectiveness of Mentha piperita Leaf Extracts against Oral Pathogens: An in vitro Study

AIM

The study aims to assess the Mentha piperita leaf extract's effectiveness against oral pathogens.

MATERIALS AND METHODS

The leaf extract of M. piperita was prepared using cold water method. The three microbial strains, i.e., Streptococcus mutans, Aggregatibacter actinomycetem-comitans, and Candida albicans were used as microbiological materials. Chlorhexidine 0.2% was used as positive control. The digital caliper was used to measure the zone of inhibition to know the antimicrobial activity at 24 and 48 hours. To compare the activity within and between the different microbial strains, one-way analysis of variance (ANOVA) was used. To analyze the data, Statistical Package for the Social Sciences (SPSS) software version of 21.0 was used. The p-value ≤0.05 was considered as statistically significant.

RESULTS

Maximum inhibition zone was seen in both M. piperita extracts and 0.2% chlorhexidine with S. mutans at 24 and 48 hours, followed by A. actinomycetemcomitans, and C. albi-cans respectively. The statistical analysis ANOVA reveals the statistically significant association of M. piperita extracts with p-value <0.001. The comparison with 0.2% chlorhexidine at 24 hours showed a p-value of <0.04 and at 48 hours, it showed a p-value <0.001, which was statistically significant.

CONCLUSION

The present study concluded that M. piperita showed antimicrobial activity against the oral microorganisms which are causing major less or more severe oral diseases and it can be administered as an alternative medicine for the conventional treatment.

CLINICAL SIGNIFICANCE

The study results serve as a guide in selecting and providing information about the efficacy of M. piperita extracts to the dental professionals. The discovery of a potential herbal medication would be a great development in the field of antimicrobial therapies.

Evaluation of the Efficacy of Guava Extract as an Antimicrobial Agent on Periodontal Pathogens

AIM

The present study was undertaken to assess the inhibitory effect of guava extracts on Porphyromonas gingivalis and Aggregatibacteractinomycetemcomitans, to assess the time-kill curve of P. gingivalis and A. actinomycetemcomitans, and to determine the antiproteolytic activity of guava on P. gingivalis.

MATERIALS AND METHODS

Kanamycin blood agar was used to isolate P. gingivalis and A. actinomycetemcomitans. Ethanolic guava extract (EGE) and aqueous guava extract (AGE) were prepared and the inhibitory effects of these extracts for two periodontal pathogens were tested by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) procedures. Antibacterial activity of guava extracts was determined by well diffusion method. Antiproteolytic activity of guava on protease of P. gingivalis was determined by gelatin liquefaction test.

RESULTS

The MIC determined for AGE and EGE was at 75 μL/mL concentration for P. gingivalis, whereas EGE exhibited the activity at 75 μL/mL on P. gingivalis. The MIC determined for AGE was at 50 μL/mL for A. actinomycetemcomitans, whereas MIC determined for EGE was at 3.12 μL/mL for A. actinomycetemcomitans. Porphyromonas gingivalis was susceptible to EGE compared with AGE. Aggregatibacter actinomycetemcomitans was more susceptible to guava extracts compared with P. gingivalis.

CONCLUSION

Guava extract may be a potential therapeutic agent for periodontitis as it shows significant activity against both P. gingivalis and A. actinomycetemcomitans.

CLINICAL SIGNIFICANCE

Guava leaves extract can be used as economical and suitable adjuvant to synthetic drugs and can be a potential therapeutic agent for periodontitis.

The Anti-Periodontitis Effects of Ethanol Extract Prepared Using Lactobacillus paracasei subsp. paracasei NTU 101

Poor oral health and related diseases, including caries, periodontal disease, and oral cancer, are highly prevalent across the world, particularly in the elderly. This study aimed to investigate the anti-periodontitis activity of fermented skim milk produced using the promising probiotic Lactobacillus paracasei subsp. paracasei NTU 101 (NTU101FM). An initial analysis found that an ethanol extract of NTU101FM displayed anti-oxidative activities. Further investigation of pathogen growth inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs) revealed that the NTU101FM ethanol extract also had anti-periodontal pathogen activities. In addition, the NTU101FM ethanol extract significantly decreased the release of pro-inflammatory cytokines induced by lipopolysaccharide (LPS) in RAW 264.7 macrophage cells. Finally, the NTU101FM ethanol extract was found to inhibit receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation by reducing tartrate-resistant acid phosphatase (TRAP) activity and the number of TRAP-positive multinucleated osteoclasts. In summary, our study demonstrated that ethanol extract prepared from NTU101FM has potential use as an anti-periodontitis agent.

In vitro Antimicrobial Activity of Ocimum sanctum (Tulsi) Extract on Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis

Aim: The present study was conducted with an aim to assess the antimicrobial activity of Ocimum sanctum (tulsi) extract on Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis.Materials and methods: Tulsi extract with ethanol was prepared using cold extraction method in the present in vitro study. Various concentrations (2, 4, 6, and 8%) were then obtained by dilution with dimethylformamide. A 0.2% chlorhexidine served as the positive control, whereas the negative control was dimeth-ylformamide. Zones of inhibition were measured, each for A. actinomycetemcomitans and P. gingivalis. For comparison within the group and between the study groups, one-way analysis of variance (ANOVA) and Tukey's post hoc tests were used. A statistical significance level of p < 0.05 was established. Results: The 8% concentration of the tulsi extract showed maximum zone of inhibition against A. actinomycetemcomitans and P. gingivalis (40.10 ± 0.90, 33.79 ± 1.82 mm), followed by the 6, 4, and 2% concentrations. The 0.2% chlorhexidine, which was the positive control, had 39.80 ± 1.24 and 32.28 ± 1.28 mm zones of inhibition; dimethylformamide showed 13.55 ± 1.92 and 10.21 ± 2.16 mm zones of inhibition against both the microorganisms. The ANOVA showed highly statistically significant (p < 0.0001) results between and within the groups. The antimicrobial activity of tulsi extract at 6 and 8% concentrations, and 0.2% chlorhexidine against A. actinomycetemcomitans showed statistically significant differences between the groups. The concentration of tulsi extract at 8 and 0.2% chlorhexidine on P. gingivalis showed statistically significant differences between the groups. Conclusion: It was concluded that 8% concentration of O. sanctum (tulsi) extract showed the maximum antimicrobial activity against A. actinomycetemcomitans and P. gingivalis. It is thus recommended that this may be useful as an adjunc-tive to mechanical therapy in the prevention and treatment of periodontal diseases. Clinical significance:O. sanctum (tulsi) is a herb that is abundantly available, easily accessible, economically feasible, and culturally acceptable. Therefore, it is very useful in the management of oral diseases and also for overcoming many barriers that exist for the utilization of dental services, such as affordability, accessibility, availability, and acceptability. Keywords:Aggregatibacter actinomycetemcomitans, Antimicrobial, Ocimum sanctum, Porphyromonas gingivalis.

Photodynamic therapy of Curcuma longa extract stimulated with blue light against Aggregatibacter actinomycetemcomitans

BACKGROUND AND OBJECTIVE

Curcumin, one of an established curcuminoid substances extracted from Curcuma longa, has been used as a photosensitizer (PS) in photodynamic therapy (PDT). Curcuminoid substances has been reported to have benefits in treating dental chronic infection and inflammation diseases, such as chronic periodontitis. The purpose of this study was to find the optimum concentration of Curcuma longa (CL) extract, containing all curcuminoid substances, and the power density of blue light (BL) in photodynamic therapy against periodontally pathogenic bacteria, A. actinomycetemcomitans.

METHODS

Antibacterial activity of various concentrations of CL extract against A. actinomycetemcomitans was determined. Exponentially growing bacteria were combined with 2-fold dilution of CL extract solution ranging from 25 to 0.098 μg/ml. Co-culture bacteria treated with 0.12% chlorhexidine (CHX) served as the positive control. The effect of photostimulation with light emitting diode (LED) 420-480 nm at 16.8 J/cm² for 1 min on the selected concentration of CL extract was examined. Bacteria viability was determined by plate counting technique. In addition, production of free radicals was tested by electron spin resonance spectroscope (ESR) with 5,5-dimethyl-1-pyrroline N-oxide (DMPO).

RESULTS

The antibacterial activity of CL extract was dose dependent. Without BL, 25 μg/ml CL extract showed 6.03 ± 0.39 log₁₀A. actinomycetemcomitans. Interestingly, the combination of BL and 0.78 μg/ml CL extract solution showed complete absence of A. actinomycetemcomitans. Peak signal intensity of hydroxyl radical production was also detected with the combination of BL and CL.

CONCLUSIONS

CL extract not only had antimicrobial activity but also could be used as an effective PS when stimulated with BL in PDT. The optimal antibacterial effect of CL extract with BL was equal to the standard oral disinfectant, 0.12% CHX.

Electrospun polycaprolactone nanofibres decorated by drug loaded chitosan nano-reservoirs for antibacterial treatments

The main limitation of conventional antibiotic therapies concerns the low efficacy to fight bacteria attacks during long treatment times. In this context, the integrated use of electrofluidodynamics (EFDs)-basically electrospinning and electrospraying-may represent an interesting route for designing nanostructured platforms with controlled release to prevent the formation of bacterial biofilms in oral implant sites. They allow for the deposition of nanofibres and nanoparticles by different modes-i.e. sequential, simultaneous-for the fabrication of more efficacious systems in terms of degradation protection, pharmacokinetic control and drug distribution to the surrounding tissues. Herein, we will investigate EFDs processing modes and conditions to decorate polycaprolactone nanofibres surfaces by chitosan nano-reservoirs for the administration of Amoxicillin Trihydrate as an innovative antibacterial treatment of the periodontal pocket.

Composition and Antibacterial Activity of the Essential Oils of Orthosiphon stamineus Benth and Ficus deltoidea Jack against Pathogenic Oral Bacteria

In this study, the essential oils of Orthosiphon stamineus Benth and Ficus deltoidea Jack were evaluated for their antibacterial activity against invasive oral pathogens, namely Enterococcus faecalis, Streptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Chemical composition of the oils was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of the oils and their major constituents were investigated using the broth microdilution method (minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)). Susceptibility test, anti-adhesion, anti-biofilm, checkerboard and time-kill assays were also carried out. Physiological changes of the bacterial cells after exposure to the oils were observed under the field emission scanning electron microscope (FESEM). O. stamineus and F. deltoidea oils mainly consisted of sesquiterpenoids (44.6% and 60.9%, respectively), and β-caryophyllene was the most abundant compound in both oils (26.3% and 36.3%, respectively). Other compounds present in O. stamineus were α-humulene (5.1%) and eugenol (8.1%), while α-humulene (5.5%) and germacrene D (7.7%) were dominant in F. deltoidea. The oils of both plants showed moderate to strong inhibition against all tested bacteria with MIC and MBC values ranging 0.63–2.5 mg/mL. However, none showed any inhibition on monospecies biofilms. The time-kill assay showed that combination of both oils with amoxicillin at concentrations of 1× and 2× MIC values demonstrated additive antibacterial effect. The FESEM study showed that both oils produced significant alterations on the cells of Gram-negative bacteria as they became pleomorphic and lysed. In conclusion, the study indicated that the oils of O. stamineus and F. deltoidea possessed moderate to strong antibacterial properties against the seven strains pathogenic oral bacteria and may have caused disturbances of membrane structure or cell wall of the bacteria.

Bismuth subsalicylate nanoparticles with anaerobic antibacterial activity for dental applications

In recent years, nanomaterials have been used in the medical-dental field as new alternative antimicrobial agents. Bismuth subsalicylate (BSS) has been used as an antimicrobial agent, but the effect of BSS in the form of nanoparticles (BSS-nano) as a potential antimicrobial agent has not been tested, in specific against bacteria responsible for periodontal disease. The aim of this study was to evaluate the antibacterial effect of BSS-nano against oral anaerobic bacteria and to assess the safety of BSS-nano by evaluating their cytotoxicity in human gingival fibroblast (HGF-1) cells. BSS-nano were synthesized by laser ablation and were previously physico-chemically characterized using in vitro assays. The antibacterial activity was measured using the tetrazolium-based XTT assay, and cytotoxicity was determined using lactate dehydrogenase (LDH) and MTS assays in HGF-1 cells. Transmission electron microscopy of HGF-1 exposed to BSS-nano was also performed. BSS-nano was shown to have a primary size of 4-22 nm and a polygonal shape. Among the tested bacterial strains, those with a greater sensitivity to BSS-nano (highest concentration of 21.7 μg ml^-1) were A. actinomycetemcomitans, C. gingivalis, and P. gingivalis. BSS-nano at a concentration of 60 μg ml^-1 showed low cytotoxicity (6%) in HFG-1 cells and was mainly localized intracellularly in acidic vesicles. Our results indicate that the concentration of BSS-nano used as an effective antibacterial agent does not induce cytotoxicity in mammalian cells; thus, BSS-nano can be applied as an antibacterial agent in dental materials or antiseptic solutions.

Inhibition of malodorous gas formation by oral bacteria with cetylpyridinium and zinc chloride

OBJECTIVE

The antimicrobial efficacy of zinc- (ZnCl₂) and cetylpyridinium-chloride (CPC) and their inhibition capacity on volatile sulfur compound (VSC) production by oral bacterial strains were investigated.

DESIGN

Minimum inhibitory concentrations (MIC) and growth curves were determined for ZnCl₂, CPC, and CPC with ZnCl₂ solutions against eight oral microorganisms (Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, Tannerella forsythia, Staphylococcus aureus and Streptococcus mutans) known to be involved in the pathophysiology of both halitosis and periodontal disease. Gas chromatography was applied to measure VSCs (H₂S, CH₃SH, (CH₃)₂S) production levels of each strains following exposure to the solutions.

RESULTS

ZnCl₂ and CPC effectively inhibited growth of all eight strains. ZnCl₂ was generally more effective than CPC in suppressing bacterial growth excluding A. actinomycetemcomitans, P. intermedia, and T. forsythia. Synergism between CPC and ZnCl₂ was shown in A. actinomycetemcomitans. The MIC for CPC was significantly lower than ZnCl₂. VSC production was detected in five bacterial strains (A. actinomycetemcomitans, F. nucleatum, P. gingivalis, T. denticola, and T. forsythia). Each bacterial strain showed unique VSCs production profiles. H₂S was produced by F. nucleatum, P. gingivalis, and T. denticola, CH₃SH by all five strains and (CH₃)₂S by A. actinomycetemcomitans, F. nucleatum, P. gingivalis, and T. denticola. Production of CH₃SH, the most malodorous component among the three major VSCs from mouth air was evident in F. nucleatum and T. forsythia.

CONCLUSION

Both ZnCl₂ and CPC effectively inhibit bacterial growth causative of halitosis and periodontal disease, resulting in a direct decrease of bacterial VSCs production.

Application of diverse natural polymers in the design of oral gels for the treatment of periodontal diseases

The objective of this study was to prepare periodontal gels using natural polymers such as badam gum, karaya gum and chitosan. These gels were tested for their physical and biochemical properties and assessed for their antibacterial activity against Aggregatibacter actinomycetemcomitans and Streptococcus mutans, two pathogens associated with periodontal disease. Badam gum, karaya gum and chitosan were used to prepare gels of varying concentrations. Moxifloxacin hydrochloride, a known antimicrobial drug was choosen in the present study and it was added to the above gels. The gels were then run through a battery of tests in order to determine their physical properties such as pH and viscosity. Diffusion studies were carried out on the gels containing the drug. Antimicrobial testing of the gels against various bacteria was then carried out to determine the effectiveness of the gels against these pathogens. The results showed that natural polymers can be used to produce gels. These gels do not have inherent antimicrobial properties against A. actinomycetemcomitans and S. mutans. However, they can be used as a transport vehicle to carry and release antimicrobial drugs.

In situ Biofilm Formation by Multi-species Oral Bacteria Under Flowing and Anaerobic Conditions

An understanding of biofilm behavior of periodontopathic bacteria is key to the development of effective oral therapies. We hypothesized that interspecies bacterial aggregates play an important role in anaerobic biofilm establishment and proliferation, and contribute to the survivability of the biofilm against therapeutic agents. The system developed in this study assessed a multi-species ( Streptococcus gordonii, Actinobacillus actinomycetemcomitans, and Fusobacterium nucleatum) biofilm formation under anaerobic and flowing conditions with the use of an in situ image analysis system. The biofilm was comprised of a base film of non-aggregated cells and complex interspecies aggregates that formed in the planktonic phase which rapidly colonized the surface, reaching 58 ± 9% and 65 ± 11.8% coverage by 5 and 24 hrs, respectively. Upon SDS (0.1%) treatment of a 24-hour biofilm, substantial detachment (55 ± 14%, P < 0.05) of the aggregates was observed, while the base film bacteria remained attached but non-viable. Rapid re-establishment of the biofilm occurred via attachment of viable planktonic aggregates.

A Modified Glycosaminoglycan, GM-0111, Inhibits Molecular Signaling Involved in Periodontitis

Background

Periodontitis is characterized by microbial infection, inflammation, tissue breakdown, and accelerated loss of alveolar bone matrix. Treatment targeting these multiple stages of the disease provides ways to treat or prevent periodontitis. Certain glycosaminoglycans (GAGs) block multiple inflammatory mediators as well as suppress bacterial growth, suggesting that these GAGs may be exploited as a therapeutic for periodontitis.

Methods

We investigated the effects of a synthetic GAG, GM-0111, on various molecular events associated with periodontitis: growth of Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) pathogenic bacteria associated with periodontitis; activation of pro-inflammatory signaling through TLR2 and TLR4 in mouse macrophage RAW 264.7 cells and heterologously expressed HEK 293 cells; osteoclast formation and bone matrix resorption in cultured mouse pre-osteoclasts.

Results

(1) GM-0111 suppressed the growth of P. gingivalis and A. actinomycetemcomitans even at 1% (w/v) solution. The antibacterial effects of GM-0111 were stronger than hyaluronic acid (HA) or xylitol in P. gingivalis at all concentrations and comparable to xylitol in A. actinomycetemcomitans at ≥2% (w/v) solution. We also observed that GM-0111 suppressed biofilm formation of P. gingivalis and these effects were much stronger than HA. (2) GM-0111 inhibited TLR-mediated pro-inflammatory cellular signaling both in macrophage and HEK 293 cells with higher selectivity for TLR2 than TLR4 (IC₅₀ of 1–10 ng/mL vs. > 100 μg/mL, respectively). (3) GM-0111 blocked RANKL-induced osteoclast formation (as low as 300 ng/mL) and bone matrix resorption. While GM-0111 showed high affinity binding to RANKL, it did not interfere with RANKL/RANK/NF-κB signaling, suggesting that GM-0111 inhibits osteoclast formation by a RANKL-RANK-independent mechanism.

Conclusions

We report that GM-0111 inhibits multiple molecular events involved in periodontitis, spanning from the early pro-inflammatory TLR signaling, to pathways activated at the later stage component of bone loss.

Comparison of Riboflavin and Toluidine Blue O as Photosensitizers for Photoactivated Disinfection on Endodontic and Periodontal Pathogens In Vitro

Photoactivated disinfection has a strong local antimicrobial effect. In the field of dentistry it is an emerging adjunct to mechanical debridement during endodontic and periodontal treatment. In the present study, we investigate the effect of photoactivated disinfection using riboflavin as a photosensitizer and blue LED light for activation, and compare it to photoactivated disinfection with the widely used combination of toluidine blue O and red light. Riboflavin is highly biocompatible and can be activated with LED lamps at hand in the dental office. To date, no reports are available on the antimicrobial effect of photoactivated disinfection using riboflavin/blue light on oral microorganisms. Planktonic cultures of eight organisms frequently isolated from periodontal and/or endodontic lesions (Aggregatibacter actinomycetemcomitans, Candida albicans, Enterococcus faecalis, Escherischia coli, Lactobacillus paracasei, Porphyromonas gingivalis, Prevotella intermedia and Propionibacterium acnes) were subjected to photoactivated disinfection with riboflavin/blue light and toluidine blue O/red light, and survival rates were determined by CFU counts. Within the limited irradiation time of one minute, photoactivated disinfection with riboflavin/blue light only resulted in minor reductions in CFU counts, whereas full kills were achieved for all organisms when using toluidine blue O/red light. The black pigmented anaerobes P. gingivalis and P. intermedia were eradicated completely by riboflavin/blue light, but also by blue light treatment alone, suggesting that endogenous chromophores acted as photosensitizers in these bacteria. On the basis of our results, riboflavin cannot be recommended as a photosensitizer used for photoactivated disinfection of periodontal or endodontic infections.

Evaluation of the Antibacterial Effect of Silver Nanoparticles on Guided Tissue Regeneration Membrane Colonization--An in Vitro Study

OBJECTIVE

The aim of this in vitro study was to investigate the colonization and penetration of specific bacteria on nanosilver-impregnated GTR (guided tissue regeneration) membranes.

METHODS

Three sets of GTR membranes were used in this study: 1) GTR-C: Plain GTR membrane as a negative control; 2) GTR-NS: GTR membrane impregnated with silver nanoparticles as the test group; 3) GTR-DOX: GTR membrane impregnated with 25% (w/w) doxycycline hydrochloride acting as a positive control. Stress-strain characteristics were calculated to determine the physical properties of the control and impregnated membranes. Qualitative observation of microbial adherence and bacterial penetration through GTR membranes were performed by using four organisms (Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Porphyromonas gingivalis) reported to have strong adherent capabilities to collagen membranes.

RESULTS

The mean bacterial adherence scores were significantly greater (p < 0.001) in the GTR-C group when compared to GTR-DOX and GTR-NS groups. GTR-NS showed lower adherence scores than GTR-DOX across all four microorganisms; this difference, however was not statistically significant. The difference in colony forming units (CFUs) was highly significant (p < 0.001), suggesting greater penetration in GTR-C membranes when compared to GTR-NS and GTR-DOX groups. Though the mean CFUs were lower in GTR-DOX than in GTR-NS across all four microorganisms, this difference was statistically significant only for S. mutans and F. nucleatum.

CONCLUSION

The incorporation of silver nanoparticles may be of value when controlling membrane-associated infection. Studies with different nanosilver particle sizes should be conducted to further evaluate the beneficial properties of nanosilver against periodontal pathogens.

[Antibacterial effect of the carboxymethyl chitosan zinc peptide on several periodontal pathogens in vitro]

OBJECTIVE

To determine the antimicrobial effects of carboxymethyl chitosan zinc (CMC-Zn(+)) and CMC-Zn(+)-peptide (CMC-Zn(+)-P) on four kinds of periodontal pathogens.

METHODS

Dilution method was used to determine the minimum inhibitory concentration (MIC) of CMC-Zn(+) for Porphyromonas gingivalis (Pg), Actinobacillusactinomycetemcomitans (Aa), Prevotella intermedia (Pi) and Actinomyces viscosus (Av). The antimicrobial characters of CMC-Zn(+) and CMC-Zn(+)-P on these four kinds of pathogens were evaluated by disk diffusion method.

RESULTS

The MIC of CMC-Zn(+) for Pg, Aa, Pi and Av was 0.312 5%, 0.156 25%, 0.156 25% and 0.078 125% respectively. Significant antimicrobial effects were improved along with the increased concentration of CMC-Zn(+) and CMC-Zn(+)-P (P < 0.01), while the best antimicrobial concentrations of both CMC-Zn(+) and CMC-Zn(+)-P were 5%. The antimicrobial effect of CMC-Zn(+)-P was better than that of CMC-Zn(+) on the same kind of periodontal pathogen (P < 0.01). CMC-Zn(+)-P showed different antimicrobial effects on the four periodontal pathogens (Av > Aa > Pi or Av > Aa > Pg, P < 0.01).

CONCLUSIONS

CMC-Zn(+) and CMC-Zn(+)-P have inhibition effect on Pg, Aa, Pi and Av, and the best antibacterial concentration was 5%. The CMC-Zn(+)-P has better antibacterial effect than CMC-Zn(+) on Pg, Aa, Pi and Av.

The effect of metronidazole on the presence of P. gingivalis and T. forsythia at 3 and 12 months after different periodontal treatment strategies evaluated in a randomized, clinical trial

OBJECTIVE

The benefit of full-mouth disinfection (FDIS) over traditional scaling and root planing (SRP) in the treatment of chronic, destructive periodontitis remains equivocal and it is not known whether the use of adjunctive antibiotics may enhance the effect of FDIS. Therefore, the aim of this study was to evaluate the effect of conventional SRP completed over 21 days or 1-day FDIS, with or without systemically delivered adjunctive metronidazole (MET) on the presence of P. gingivalis and T. forsythia after 3 and 12 months.

MATERIALS AND METHODS

One hundred and eighty-four patients with moderate-to-severe periodontitis were randomly allocated to one of four treatment groups; (1) FDIS+MET; (2) FDIS+placebo; (3) SRP+MET; (4) SRP+placebo. Prior to treatment, pooled subgingival samples were obtained from the five deepest pockets. The same sites were sampled again 3 and 12 months after treatment. All samples were analyzed for P. gingivalis and T. forsythia by PCR, whereas A. actinomycetemcomitans and other bacteria were identified by culture techniques.

RESULTS

At baseline, 47% of the samples were positive for P. gingivalis, while almost all samples were positive for T. forsythia. The occurrence of P. gingivalis and T. forsythia was significantly reduced at 3 and 12 months after treatment in the FDIS+MET group, but not in the other treatment groups.

CONCLUSION

FDIS+MET had a significant effect in patients with P. gingivalis and T. forsythia, resulting in a significant reduction in number of patients where these micro-organisms could be detected at 3 and 12 months post-therapy.

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.

Synergistic anti-inflammatory activity of the antimicrobial peptides human beta-defensin-3 (hBD-3) and cathelicidin (LL-37) in a three-dimensional co-culture model of gingival epithelial cells and fibroblasts

Given the spread of antibiotic resistance in bacterial pathogens, antimicrobial peptides that can also modulate the immune response may be a novel approach for effectively controlling periodontal infections. In the present study, we used a three-dimensional (3D) co-culture model of gingival epithelial cells and fibroblasts stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) to investigate the anti-inflammatory properties of human beta-defensin-3 (hBD-3) and cathelicidin (LL-37) and to determine whether these antimicrobial peptides can act in synergy. The 3D co-culture model composed of gingival fibroblasts embedded in a collagen matrix overlaid with gingival epithelial cells had a synergistic effect with respect to the secretion of IL-6 and IL-8 in response to LPS stimulation compared to fibroblasts and epithelial cells alone. The 3D co-culture model was stimulated with non-cytotoxic concentrations of hBD-3 (10 and 20 µM) and LL-37 (0.1 and 0.2 µM) individually and in combination in the presence of A. actinomycetemcomitans LPS. A multiplex ELISA assay was used to quantify the secretion of 41 different cytokines. hBD-3 and LL-37 acted in synergy to reduce the secretion of GRO-alpha, G-CSF, IP-10, IL-6, and MCP-1, but only had an additive effect on reducing the secretion of IL-8 in response to A. actinomycetemcomitans LPS stimulation. The present study showed that hBD-3 acted in synergy with LL-37 to reduce the secretion of cytokines by an LPS-stimulated 3D model of gingival mucosa. This combination of antimicrobial peptides thus shows promising potential as an adjunctive therapy for treating inflammatory periodontitis.

Nanoparticle-encapsulated chlorhexidine against oral bacterial biofilms

BACKGROUND

Chlorhexidine (CHX) is a widely used antimicrobial agent in dentistry. Herein, we report the synthesis of a novel mesoporous silica nanoparticle-encapsulated pure CHX (Nano-CHX), and its mechanical profile and antimicrobial properties against oral biofilms.

METHODOLOGY/PRINCIPAL FINDINGS

The release of CHX from the Nano-CHX was characterized by UV/visible absorption spectroscopy. The antimicrobial properties of Nano-CHX were evaluated in both planktonic and biofilm modes of representative oral pathogenic bacteria. The Nano-CHX demonstrated potent antibacterial effects on planktonic bacteria and mono-species biofilms at the concentrations of 50-200 µg/mL against Streptococcus mutans, Streptococcus sobrinus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Enterococccus faecalis. Moreover, Nano-CHX effectively suppressed multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans and Porphyromonas gingivalis up to 72 h.

CONCLUSIONS/SIGNIFICANCE

This pioneering study demonstrates the potent antibacterial effects of the Nano-CHX on oral biofilms, and it may be developed as a novel and promising anti-biofilm agent for clinical use.

Clinical and microbiological effects of levofloxacin in the treatment of Aggregatibacter actinomycetemcomitans-associated periodontitis: a randomized placebo-controlled clinical trial

AIM

To evaluate the clinical and microbiological effects of systemic levofloxacin (LFX) in subjects with Aggregatibacter actinomycetemcomitans-associated chronic periodontitis (AA-ACP).

MATERIALS AND METHODS

Subjects with severe periodontitis with subgingival detection of A. actinomycetemcomitans were randomly divided into two treatment groups; a test group (n = 35) that received scaling and root planing (SRP) and LFX (500 mg o.d.) and a control group (n = 34) that received SRP and placebo (o.d.) for 10 days. Plaque index (PI), gingival index (GI), percent of sites with bleeding on probing (% BoP), probing depth (PD) and clinical attachment level (CAL) were recorded and subgingival plaque samples were cultivated for detection of A. actinomycetemcomitans at baseline to 6 months at various intervals.

RESULTS

Subjects receiving LFX showed the greatest improvements in mean PD and CAL. The difference in the reduction of PD and CAL in the two groups was significant at 1, 3 and 6 months for PD and 3 and 6 months for CAL (p < 0.05). The inter-group difference in PI, GI and % BoP was not significant at any interval. Detectable levels of A. actinomycetemcomitans were significantly less in the test group 3 and 6 months post-therapy.

CONCLUSION

Systemic LFX as an adjunct to SRP improves clinical outcomes and suppresses A. actinomycetemcomitans below detectable levels.

Pro-oxidative synergic bactericidal effect of NO: kinetics and inhibition by nitroxides

NO plays diverse roles in physiological and pathological processes, occasionally resulting in opposing effects, particularly in cells subjected to oxidative stress. NO mostly protects eukaryotes against oxidative injury, but was demonstrated to kill prokaryotes synergistically with H2O2. This could be a promising therapeutic avenue. However, recent conflicting findings were reported describing dramatic protective activity of NO. The previous studies of NO effects on prokaryotes applied a transient oxidative stress while arbitrarily checking the residual bacterial viability after 30 or 60min and ignoring the process kinetics. If NO-induced synergy and the oxidative stress are time-dependent, the elucidation of the cell killing kinetics is essential, particularly for survival curves exhibiting a "shoulder" sometimes reflecting sublethal damage as in the linear-quadratic survival models. We studied the kinetics of NO synergic effects on H2O2-induced killing of microbial pathogens. A synergic pro-oxidative activity toward gram-negative and gram-positive cells is demonstrated even at sub-μM/min flux of NO. For certain strains, the synergic effect progressively increased with the duration of cell exposure, and the linear-quadratic survival model best fit the observed survival data. In contrast to the failure of SOD to affect the bactericidal process, nitroxide SOD mimics abrogated the pro-oxidative synergy of NO/H2O2. These cell-permeative antioxidants, which hardly react with diamagnetic species and react neither with NO nor with H2O2, can detoxify redox-active transition metals and catalytically remove intracellular superoxide and nitrogen-derived reactive species such as (•)NO2 or peroxynitrite. The possible mechanism underlying the bactericidal NO synergy under oxidative stress and the potential therapeutic gain are discussed.

Comparison of the penetration and passage of Streptococcus mutans and Aggregatibacter actinomycetemcomitans through membranes loaded with tetracycline, amoxicillin, and chlorhexidine: an in vitro study

BACKGROUND

This study aimed at comparing the colonization and passage of Streptococcus mutans and Aggregatibacter actinomycetemcomitans (Aa) through polytetrafluoroethylene (PTFE) and acellular dermal matrix (ADM) membranes loaded with tetracycline, amoxicillin, and chlorhexidine.

METHODS

In this in vitro study, PTFE and ADM membranes were loaded with tetracycline, amoxicillin, and chlorhexidine. The colonization and crossing of S. mutans and Aa through these membranes were evaluated using vials containing culture medium. Three-way analysis of variance and Tukey's honestly significant difference test were used for the statistical analyses (p<0.05).

RESULTS

The membranes loaded with antimicrobial agents significantly decreased bacterial passage compared with the control membranes (not loaded with antimicrobial agents). Significant differences were also detected between membranes in their inhibitory properties (p=0.011). PTFE membrane had higher barrier effect than ADM. Tetracycline had greater antibacterial activity against both species compared with amoxicillin (p=0.021) but had no significant difference with chlorhexidine in this respect (p=0.068). The antimicrobial efficacy of chlorhexidine was in between those of tetracycline and amoxicillin, but the difference between amoxicillin and chlorhexidine in this respect was not statistically significant (p=0.992). Aa had better penetration into the membranes compared with S. mutans.

CONCLUSIONS

The study results demonstrated that the penetration of S. mutans and Aa decreased into the membranes loaded with tetracycline, amoxicillin, and chlorhexidine and PTFE membrane had a greater barrier effect than ADM. Loading membranes with antimicrobial agents can effectively reduce membrane-associated infections during regenerative procedures.

Antibacterial potential of Manuka honey against three oral bacteria in vitro

Honey is an ancient natural remedy for the treatment of infected wounds. It has regained attention in the medical profession, as it has recently been reported to have a broad-spectrum inhibitory effect against bacteria. Data concerning Manuka honey of New Zealand origin, which is claimed to provide additional non-peroxide antimicrobial activity (so-called standard NPA) against oral pathogens, is still scarce. Therefore, this study aimed to screen for the antibacterial efficacy of different Manuka honey products against S. mutans (OMZ 918), P. gingivalis (OMZ 925) and A. actinomycetemcomitans (OMZ 299). Chlorhexidine and saline served as positive and negative controls, respectively, whereas a Swiss multifloral honey served as control honey without intrinsic non-peroxide activity. Chlorhexidine showed the highest inhibiting potential against all specimens tested. Manuka honey below an NPA value of 15 showed the least bacterial growth-inhibiting potential, even less – although not significantly so – than multifloral Swiss honey. Manuka honey above an NPA value of 15 showed a significantly higher antibacterial effect compared to the other honeys tested. All Manuka honey preparations were more effective in inhibiting the growth of P. gingivalis and A. actinomycetemcomitans, rather than S. mutans. In conclusion, the study showed an NPA dose-dependent antibacterial efficacy of Manuka honey. Further investigations of this natural product are now open for scrutiny.

Aggregatibacter actinomycetemcomitans biofilm killing by a targeted ciprofloxacin prodrug

A pH-sensitive ciprofloxacin prodrug was synthesized and targeted against biofilms of the periodontal pathogen Aggregatibacter actinomycetemcomitans (Aa). The dose required to reduce the viability of a mature biofilm of Aa by ~80% was in the range of ng cm(-2) of colonized area (mean biofilm density 2.33 × 10(9) cells cm(-2)). A mathematical model was formulated that predicts the temporal change in the concentration of ciprofloxacin in the Aa biofilm as the drug is released and diffuses into the bulk medium. The predictions of the model were consistent with the extent of killing obtained. The results demonstrate the feasibility of the strategy to induce mortality, and together with the mathematical model, provide the basis for design of targeted antimicrobial prodrugs for the topical treatment of oral infections such as periodontitis. The targeted prodrug approach offers the possibility of optimizing the dose of available antimicrobials in order to kill a chosen pathogen while leaving the commensal microbiota relatively undisturbed.

Evaluating the antimicrobial activity of commercially available herbal toothpastes on microorganisms associated with diabetes mellitus

AIM

The present study was conducted to evaluate the effcacy of commercially available herbal toothpastes against the different periodontopathogens.

MATERIALS AND METHODS

Six herbal toothpastes that were commonly commercially available were included in the study. Colgate herbal, Babool, Meswak, Neem active, Dabur red toothpastes were tested for the study whereas sterile normal saline was used as control. Antimicrobial effcacies of dentifrices were evaluated against Streptococcus mutans and Actinobacillus actinomycetemcomitans. The antimicrobial properties of dentifrices were tested by measuring the maximum zone of inhibition at 24 hours on the Mueller Hinton Agar media inoculated with microbial strain using disk diffusion method. Each dentifrice was tested at 100% concentration (full strength).

RESULTS

The study showed that all dentifrices selected for the study were effective against the entire test organism but to varying degree. Neem active tooth paste gave a reading of 25.4 mm as the zone of inhibition which was highest amongst all of the test dentifrices. Colgate Herbal and Meswak dentifrices recorded a larger maximum zone of inhibition, measuring 23 and 22.6 mm respectively, compared to other toothpastes. All other dentifrices showed the zone of inhibition to be between 17 and 19 mm respectively.

CONCLUSION

The antibacterial properties of six dentifrices were studied in vitro and concluded that almost all of the dentifrices available commercially had antibacterial properties to some extent to beneft dental health or antiplaque action.

A comparison of Aggregatibacter actinomycetemcomitans (Aa) virulence traits in a rat model for periodontal disease

Our aim was to explore the effects of Cytolethal Distending toxin (Cdt) in a well established rat model of periodontal disease where leukotoxin (LtxA) was thought to have no known effect. In vitro studies, were used to assess CdtB activity using Aa Leukotoxin as a negative control. These studies showed that both CdtB and LtxA (unexpectedly) exerted significant effects on CD4⁺ T cells. As a result we decided to compare the effects of these two prominent Aa virulence factors on bone loss using our rat model of Aa-induced periodontitis. In this model, Aa strains, mutant in cdtB and ltxA, were compared to their parent non-mutant strains and evaluated for colonization, antibody response to Aa, bone loss and disease. We found that bone loss/disease caused by the ltxA mutant strain, in which cdtB was expressed, was significantly less (p<0.05) than that due to the wild type strain. On the other hand, the disease caused by cdtB mutant strain, in which ltxA was expressed, was not significantly different from the wild type strain. This data indicates that Aa LtxA exerts a greater effect on bone loss than Cdt in this rat model of periodontal disease and supports the utility of this model to dissect specific virulence factors as they relate to immunopathology in studies of Aa-induced disease.

A randomized controlled clinical trial on the clinical and microbiological efficacy of systemic satranidazole in the treatment of chronic periodontitis

OBJECTIVE

The present clinical trial was designed to investigate the effectiveness of systemic satranidazole (SZ) as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis.

METHODS

Sixty-six subjects presenting with at least twelve teeth with probing depth (PD) > or = 4 mm were selected. Thirty-three subjects were randomly assigned to full-mouth SRP + placebo (Group 1) and 33 subjects were assigned to full-mouth SRP + SZ (Group 2). The clinical outcomes evaluated were plaque index (PI), gingival index (GI), clinical attachment level (CAL) and PD at baseline, 1 month, 3 months and 6 months. Also, microbial analysis of dental plaque using polymerase chain reaction was done at baseline, 3 and 6 months to estimate the number of sites harboring periodontopathogens.

RESULTS

Sixty subjects were evaluated up to 6 months. At 6 months, Group 2 showed greater mean reduction (3.84 +/- 1.31 mm) in PD as compared to Group 1 (1.42 +/- 1.01 mm; p < 0.05) and there was a greater mean CAL gain (3.22 +/- 1.01 mm) in Group 2 as compared to Group 1 (1.15 +/- 1.49 mm; p < 0.05). These subjects also showed significant reductions in the number of certain periodontopathogens, such as Tannerella forsythia, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans.

CONCLUSION

The systemic use of SZ, when used as an adjunct to non-surgical periodontal therapy in subjects with periodontitis, achieves significantly better clinical and microbiological results than scaling and root planing alone.

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.

The antimicrobial activity of the three commercially available intense sweeteners against common periodontal pathogens: an in vitro study

AIM

To evaluate the in vitro antimicrobial activity of three commercially available intense sweeteners against two common periodontal pathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans.

MATERIALS AND METHODS

Three commercially available intense sweeteners namely saccharin, aspartame and sucralose were obtained and powdered. Necessary concentrations of the sweeteners were prepared by mixing them with an inert solvent. The antimicrobial efficacy was assessed using agar well diffusion technique. Statistical analysis was done using one-way ANOVA followed by Tukey's post hoc test. p-value < 0.05 was considered statistically significant.

RESULTS

All the three sweeteners showed significant antimicrobial activity against the periodontal pathogens tested. Sucralose containing sucralose showed maximum zone of inhibition, against Aggregatibacter actinomycetemcomitans. Saccharin and aspartame containing saccharin and aspartame respectively, showed maximum zone of inhibition, against Porphyromonas gingivalis.

CONCLUSION

All the sweeteners used in this study have demonstrated significant antimicrobial activity. Therefore, these sweeteners could be recommended as an ideal alternative to sucrose.

CLINICAL SIGNIFICANCE

Dental caries and periodontal diseases are ubiquitous diseases of mankind caused by microorganisms. Dental caries is caused by sucrose. By altering the source like intense sweetener we can combat caries as well as with its antimicrobial properties against periodontopathic bacteria, we can reduce prevalence of periodontal diseases.

Antibacterial activity of the lactoperoxidase system combined with edible Laminaria hot-water extract as a source of halide ions

Hot-water extracts prepared from nine out of 12 samples of dried edible Laminaria reduced the viable numbers of Aggregatibacter actinomycetemcomitans, Staphylococcus aureus, and Esherichia coli below the detection limit after incubation for 5 min when combined with lactoperoxidase, glucose oxidase, and glucose. Some extracts showed higher bactericidal activity and a higher OI(-) concentration in the assay mixture after ultrafiltration.

Antibacterial effect of silver-platinum coating for orthodontic appliances

OBJECTIVE

To develop a hard coating for stainless surfaces based on silver (Ag)-platinum (Pt) alloys.

MATERIALS AND METHODS

Ag-Pt alloys, which have high degree of biocompatibility, excellent resistance to sterilization conditions, and antibacterial properties to different bacteria, are associated with long-term antibacterial efficiency. Approximately 1.03-µm to 2.34-µm-thick coatings, as determined by scanning electron microscopy, were deposited on stainless surfaces by the simultaneous vaporization of both metals (Ag and Pt) in an inert argon atmosphere. The coating was done by physical vapor deposition. Microorganisms and eukaryotic culture cells were grown on these surfaces.

RESULTS

The coatings released sufficient Ag ions when immersed in phosphate-buffered saline and showed significant antimicrobial potency against Streptococcus mutans and Aggregatibacter actinomycetemcomitans strains. At the same time, human gingival fibroblast cells were not adversely affected.

CONCLUSION

Ag-Pt coatings on load-bearing orthodontic bracket surfaces can provide suitable antimicrobial activity during active orthodontic treatment.

Diode laser activated indocyanine green selectively kills bacteria

BACKGROUND AND OBJECTIVE

Commercially available photodynamic therapy for periodontal diseases utilizes methylene blue as a photosensitizer. Here we propose a novel photosensitizer dye, indocyanine green (ICG), because it can be readily activated by commercially available dental 810 nm diode lasers and has an established safety record as an intravascular agent in cardiac imaging and ophthalmologic photodynamic therapy. Therefore, we aim to characterize ICG uptake and killing of key periodontal pathogens to explore its potential as a periodontal photodynamic therapy agent.

MATERIALS AND METHODS

We tested ICG uptake by spectroscopy in Porphyromonas gingivalis 381 and Aggregatibacter actinomycetemcomitans, in addition to Escherichia coli DH5alpha and a human gingival epithelial cell line, HepG, in relation to ICG dose and exposure time. We then measured killing of bacteria by determining viable bacteria counts before and after exposure to ICG and 810 nm diode laser light (0-0.5 W output settings, 0-5 seconds). ICG was also applied to extracted, restored teeth, and the teeth inspected visually for staining after rinsing with saline.

RESULTS

We found rapid and significant uptake of indocyanine green into P. gingivalis 381 and A. actinomycetemcomitans 67, compared to E. coli DH5alpha and HepG gingival cell line. This correlated with significant killing of strains 381 and 67 compared to E.coli, with less than 10% survival. ICG does not appear to stain tooth surfaces and materials except calculus.

CONCLUSION

ICG combined with an 810 nm diode laser may be useful as a photodynamic adjunct for reduction of bacterial load in periodontal pockets.

Facial cellulitis because of Aggregatibacter (Actinobacillus) actinomycetemcomitans and Capnocytophaga species in an immunocompetent patient

The species of Capnocytophaga and Aggregatibacter are normal flora and mostly cause periodontal diseases. The soft tissue infection caused by Aggregatibacter often is associated with Actinomyces species. Beside, most Capnocytophaga infections are described in immunocompromised patients. We identified facial cellulitis caused by Capnocytophaga spp and Aggregatibacter (Actinobacillus) actinomycetemcomitans in a 16-year-old immunocompetent female.

[Efficient, minimally invasive periodontal therapy. An evidence based treatment concept]

A large number of reports indicate beneficial effects of systemic antibiotics for patients with periodontal diseases. Although these advantages are clear in general, the specific relationship of benefit and risk in various clinical situations remains a subject of debate. Uncertainties persist regarding the individual prescription and combination with other procedures. Since the early 1990s it has been pointed out that systemic antibiotics given in the context of non-surgical subgingival debridement may reduce the need for periodontal surgery. Recent studies confirm these findings especially with regard to the combination of amoxicillin and metronidazole. However, these antibiotics should not be viewed as a substitute for thorough debridement, or as a means to compensate for improper oral hygiene. In addition, current evidence does not provide evidence for the indiscriminate use of just any antibiotic in any periodontal patient. A treatment protocol implementing the recent evidence is shown. It is noteworthy to realize that chronic and aggressive periodontitis today can be treated successfully with simple and cost-effective means in most instances.

An in vitro comparative study determining bactericidal activity of stabilized chlorine dioxide and other oral rinses

OBJECTIVE

The study was conducted to determine the bactericidal activity of a stabilized chlorine dioxide oral rinse (ClōSYS Oral Rinse) compared to products currently available on the market.

METHODS

Oral bacteria associated with gingivitis and periodontitis were exposed to rinses for one minute and five minutes. The numbers of colony forming units per milliliter (CFU/ml) were measured prior to and following exposure to determine the bactericidal activity.

RESULTS

As expected, Listerine and Crest Pro-Health demonstrated complete kill on all bacteria exposed within one minute. Breath Rx exhibited the weakest levels of bactericidal effects overall. ClōSYS and chlorhexidine rinses proved identical 100% kills against the periodontal pathogens at five minutes; in some cases, ClōSYS oral rinse achieved a higher kill at the one-minute mark over the chlorhexidine rinse.

CONCLUSION

The results demonstrated that ClōSYS Oral Rinse has potential for providing a therapeutic benefit, making it an attractive option to induce compliance in patients concerned about taste and tooth discoloration during oral health therapy.

In vitro antibacterial efficacy of cetylpyridinium chloride-containing mouthwashes

OBJECTIVE

The objective of this study was to examine the ability of three CPC-containing mouthwashes to kill planktonic bacteria in an in vitro short-exposure assay.

METHODS

This blind study was conducted on two common oral bacterial species: Aggregatibacter (Actinobacillus) actinomycetemcomitans and Streptococcus mutans. The following mouthwashes were tested: two containing 0.075% CPC and 0.05% NaF in an alcohol-free base, and one containing 0.075% CPC and 0.05% NaF plus 6% alcohol. Additionally, a 0.05% NaF-only mouthwash was included as a negative control. Bacteria were exposed to one of the test mouthwashes for 30 seconds and then washed thoroughly, serially diluted, and plated on appropriate media to determine viable bacterial counts. Viable counts were converted to a log reduction in colony forming units (CFUs) relative to the negative control.

RESULTS

All three test mouthwashes included in this study gave a statistically significant reduction of > 3 log CFUs relative to samples treated with the negative control.

CONCLUSION

All three experimental 0.075% CPC mouthwash formulas gave a > 99.9% reduction in viable bacteria of both species following 30 seconds of treatment.

[Analysis of the inhibitory capacity against bacterial growth of several materials of dental use. Preliminar]

Dental plaque is one of the reasons for odontogenic infection. Although multiple bacteria are involved in these processes, A.actinomycetemcomitans and S.mutans are considered directly responsible for localized aggressive periodontitis and caries respectively. On the other hand, it seems clear that the oral flora utilizes especially not well polished surfaces or without bacteriastatic capacity in order to obtain better adhesion. Based on those facts we expect to prove the inhibitory capacity "in vitro" of some materials used for teeth restoration and for the cementation of accessories against one common bacterium in the human flora and two pathogenic bacteria of the oral cavity. We prepared, following the manufacturer's instructions, 18 discs for each one of the materials used in the study (2 composites and 2 ionomeros of glass). 6 discs of each material are incubated with A. actinomycetemcomitans, S. mutans and E. coli. 3 of them are incubated directly on the discs and the other 3 are incubated previously in an artificial saliva for 24 days. From the results, should be highlighted that only one of the materials demonstrated inhibitory capacity against A. actinomycetemcomitans and E. coli. None of them demonstrated inhibitory capacity against S. mutans.

The antiplaque efficacy of pomegranate mouthrinse

OBJECTIVE

to evaluate the effect of a pomegranate-containing mouthrinse on plaque, determine whether it has any adverse effects, and evaluate its antibacterial properties against selected periodontopathogens in vitro.

METHOD AND MATERIALS

thirty periodontally healthy volunteers, randomly divided into three groups, refrained from all mechanical oral hygiene measures for 4 days and used one of the randomly assigned mouthrinses (A, pomegranate; B, chlorhexidine; or C, distilled water [placebo]) twice daily. The Plaque Index (PI) was assessed at days 0 and 5. Adverse effects were also evaluated. Pomegranate extract was tested against Aggregatibacter actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), and Prevotella intermedia (P.i.).

RESULTS

in all groups, the PI significantly increased from the baseline to day 5 (P < .1). The pomegranate mouthrinse created no adverse effects. There was a statistically significant difference (P < .05) between the chlorhexidine and placebo rinse and the pomegranate and placebo rinse, but no statistically significant difference was found between the chlorhexidine and pomegranate rinse with respect to the PI. Pomegranate extract showed inhibition of all three strains of periodontopathogens at various concentrations.

CONCLUSION

these results indicate that the pomegranate mouthrinse has an antiplaque effect. Pomegranate extract is efficacious against A.a., P.g., and P.i. strains in vitro. Pomegranate mouthrinse should be explored as a long-term antiplaque rinse with prophylactic benefits.

High resistance against clindamycin, metronidazole and amoxicillin in Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans isolates of periodontal disease

OBJECTIVES

To test the antimicrobial sensitivity of two periodontal pathogens to a panel of five orally administrable antibiotics in periodontal disease.

STUDY DESIGN

A total of 69 isolates of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were processed using culture and biochemical tests. Selected colonies of A. actinomycetemcomitans and P. gingivalis were used to evaluate the antibacterial activity of clindamycin, metronidazole, amoxicillin, moxifloxacin and amoxicillin/clavulanic acid.

RESULTS

Susceptibility testing revealed a sensitivity of 100% of A. actinomycetemcomitans and P. gingivalis to moxifloxacin and amoxicillin/clavulanic acid but moderate susceptibilities were found for the rest of antibiotics agents evaluated.

CONCLUSIONS

The widespread use of antibiotics is reflected in the level of resistance of A. actinomycetemcomitans and P. gingivalis in patients with periodontal infections. This suggests that antibiotic susceptibility testing is necessary to determine efficacy of antimicrobial agents. Clinical studies with antibiotics should take these differences into account.

Maintenance after a complex orthoperio treatment in a case of generalized aggressive periodontitis: 7-year result

BACKGROUND

Generalized aggressive periodontitis (GAgP) encompasses a distinct type of periodontal disease exhibiting much more rapid periodontal tissue destruction than chronic periodontitis. The best method for management of GAgP may include the use of both regenerative periodontal techniques and the administration of systemic antibiotics.

METHODS

The treatment of a case of GAgP over a period of 6.7 years is presented in this case report. Initial periodontal therapy (week 1- 32) consisted of supragingival plaque control and three appointments of scaling and root planing. Based on the periodontal pathogens isolated (5 species), the patient also received metronidazole plus amoxicillin for one week, followed 10 weeks later by metronidazole plus amoxicillin/clavulanate for one week. The patient was put on regular supportive periodontal therapy (SPT) thereafter. Orthodontic treatment was performed after completion of the initial therapy for 96 weeks. Measurements of clinical attachment level, bleeding on probing and plaque index were obtained at every examination.

RESULTS

Antimicrobial and mechanical treatment resulted in eradication of all periopathogens and significantly improved all clinical parameters. During orthodontic treatment and active maintenance, there was no relapse of GAgP. The patient participated in SPT for 194 weeks and thereafter decided to discontinue SPT. Twenty-four months later a relapse of GAgP was diagnosed and all teeth had to be extracted.

CONCLUSIONS

These results indicate that a combined mechanical and antimicrobial treatment approach can lead to consistent resolution of GAgP. Further studies including a larger number of cases are warranted to validate these findings.

Antimicrobial activity of n-6, n-7 and n-9 fatty acids and their esters for oral microorganisms

OBJECTIVE

This study is to assess the antibacterial activity of omega-6, -7, -9 (n-6, n-7, n-9) fatty acids against various oral microorganisms.

METHODS

The n-6, n-7, n-9 fatty acids, such as gamma-linoleic acid (GLA), linoleic acid (LA), arachidonic acid (ARA), palmitoleic acid (PA), and oleic acid (OA), their fatty acid ethyl esters, GLA-EE, LA-EE, ARA-EE, PA-EE, OA-EE, and their fatty acid methyl esters, GLA-ME, LA-ME, ARA-ME, PA-ME, OA-ME, were investigated for antimicrobial activity against oral pathogens Streptococcus mutans, Candida albicans, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis. Various concentrations of the fatty acids, their methyl and ethyl esters were tested against various oral pathogens in 96-well plates and blood-agar plate. The plates were incubated anaerobically or aerobically at 37 degrees C for 48h, and the colony forming units (CFU) were determined.

RESULTS

The data demonstrated that select n-6, n-7, n-9 fatty acids and their esters exhibited strong antimicrobial activity against these oral microorganisms, demonstrating some specificity for individual microbial species.

CONCLUSION

The potential use or the combinations of the n-6, n-7, n-9 fatty acids and/or their esters, provided in a local delivery vehicle to infected sites in the oral cavity, could be considered as an additional therapeutic approach to improving oral health.

Photodynamic therapy in periodontal therapy: microbiological observations from a private practice

In recent years, the combination of laser light and photosensitizer known as photodynamic therapy (PDT) has been used in periodontal therapy. However, there are not enough clinical studies to fully evaluate the effects of PDT on the periodontal tissues. This microbiological study examined the effects of PDT on the periodontal bacteria in combination with scaling and root planing (SRP) in the same group of patients by randomly selecting PDT or SRP for use in different quadrants of the mouth. For the present study, PDT was compared with a diode laser (980 nm) and an Nd:YA G laser (1,064 nm). Microbiological samples were examined and evaluated over a period of three months. Significant bacterial reduction has been observed in all cases. The diode laser with SRP presented long-term positive results, while PDT showed a significant bacteria reduction during the entire observation period.

Hyaluronan-containing mouthwash as an adjunctive plaque-control agent

PURPOSE

Hyaluronan, commonly known as hyaluronic acid, has been shown to have anti-inflammatory action, bacteriostatic effect and antioxidant properties, thus making its use as a long-term anti-plaque and anti-gingivitis agent an appealing proposition. The aim of the present study was to evaluate the efficacy of 0.025% hyaluronan-containing mouthwash in comparison with 0.2% chlorhexidine and a water-based mouthwash and also to evaluate its antibacterial efficacy on isolated strains of periodontopathogens.

MATERIALS AND METHODS

Forty-five volunteers in a hospital setting were recruited. A single-blinded, parallel design, randomised controlled trial was carried out and the 4-day plaque re-growth model was used to study the efficacy of the three mouthwashes. Microbiological and clinical evaluation was performed by culturing and using dental indices, respectively. The three mouthwashes used in the present study were commercially available 0.025% sodium hyaluronate, 0.2% chlorhexidine and a water-based rinse (negative control). Effects of the three mouthwashes were tested on the growth of isolated strains of Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa) and Prevotella intermedia (Pi).

RESULTS

In vitro, hyaluronan had a distinct effect on the growth of Aa and Pi with no effect on the growth of Pg. In vivo, the differences between the individual rinse solutions and the water-based solution showed significantly less plaque regrowth with respect to both chlorhexidine (P = 0.033) and hyaluronan (P = 0.045) when compared to the negative control. The difference between chlorhexidine and hyaluronan was not statistically significant (P = 0.69).

CONCLUSIONS

Hyaluronan (0.025%)-containing mouthwash was comparable to chlorhexidine (0.2%) in inhibiting plaque growth in vivo, and it significantly reduced the growth of Aa and Pi in vitro

The antimicrobial efficacy of commercial dentifrices

This investigation compared the effects of a fluoride dentifrice and toothpastes formulated with antimicrobial ingredients (stannous fluoride and triclosan/copolymer) on oral micro-organisms, including those found in samples taken from the human oral cavity. Microbiological techniques determined the minimum inhibitory concentrations (MICs) of each dentifrice necessary to inhibit the growth of bacterial strains from the healthy oral cavity, as well as those found in dental caries, periodontal disease, and halitosis. Ex vivo studies utilized oral rinse samples and supragingival plaque from adults to determine antimicrobial effects on the entire microbial diversity of these samples, including biofilm-derived micro-organisms. The triclosan/copolymer dentifrice demonstrated the lowest MICs and significantly inhibited Gram-positive and Gram-negative bacteria (including the periodontal pathogens Aggregatibacter actinomycetemcomitans, Eikenella corrodens, and Fusobacterium nucleatum). In the ex vivo tests, the triclosan/copolymer dentifrice demonstrated substantial inhibition in the oral rinse samples over each treatment period (p > 0.0005) as compared to either the fluoride or stannous fluoride dentifrices. Similarly, the triclosan/copolymer dentifrice demonstrated the highest inhibition of micro-organisms in the supragingival plaque biofilm (p < 0.0005). No significant differences were observed between the fluoride and stannous fluoride dentifrices (p > 0.5).