Oral Microorganisms Research Articles

Effect of Chlorhexidine and Tea Tree Oil on Reducing the Number of Oral Microorganisms.

Thus, the aim of this study was to compare the effect of using two preoperative mouthwashes (0.12% chlorhexidine and 0.2% tea tree oil) on the number of colonies of oral microorganisms. Forty participants who needed to be rehabilitated with dental implants were included in this study. They were randomly divided into two groups (chlorhexidine group and tea tree group; n = 20, each). For each group, saliva samples were collected at four different times: T0 (initially)-before using the mouthwash, T1-after 1 minute of using the mouthwash, T10-after 10 minutes of using the mouthwash, and T60-after 60 minutes of using the mouthwash. At T0 and T1, saliva samples were collected before implant placement surgery, and at T10 and T60, saliva samples were collected during surgery. In each group, one saliva sample was collected at each evaluated time point for each patient, totaling 4 saliva collections per patient. MSB agar (Mitis-Salivarius-Bacitracin) and BHI agar (Brain Heart Infusion) culture media were used in each group. Microbial colony counts were performed using a magnifying glass and recorded in CFU (colony forming units)/mL. Statistical analyses were performed using the Friedman, Mann-Whitney U and Wilcoxon tests (p < 0.05). Based on MSB agar culture medium, at T0, the number of Streptococcus mutans colonies in the chlorhexidine group was significantly higher compared with the tea tree group (p <0.05; MSB agar). The chlorhexidine group showed significantly lower CFU/mL values for Streptococcus mutans at T1, T10, and T60 compared with the tea tree group (p <0.05; MSB agar). Based on BHI agar culture medium, at T0, the chlorhexidine group showed a significantly lower value of CFU/mL compared with the tea tree group (p < 0.05; BHI agar). At T1, T10, and T60, the chlorhexidine group showed significantly lower CFU/mL values compared with the tea tree group (p <0.05; BHI agar). Chlorhexidine is more indicated as a preoperative mouthwash than tea tree oil, due to its significantly more effective antimicrobial action.

Inflammatory macrophages exploited by oral streptococcus increase IL-1B release via NLRP6 inflammasome.

Chronic inflammatory periodontal disease develops in part from the infiltration of a large number of classically activated inflammatory macrophages that release inflammatory cytokines important for disease progression, including inflammasome-dependent interleukin (IL)-1β. Streptococcus gordonii is a normally commensal oral microorganism; while not causative, recent evidence indicates that commensal oral microbes are required for the full development of periodontal disease. We have recently reported that inflammatory macrophages counterintuitively allow for the increased survival of phagocytosed S. gordonii over nonactivated or alternatively activated macrophages. This survival is dependent on increased reactive oxygen species production within the phagosome of the inflammatory macrophages, and resistance by the bacterium and can result in S. gordonii damaging the phagolysosomes. Here, we show that activated macrophages infected with live S. gordonii release more IL-1β than non-activated macrophages infected with either live or dead S. gordonii, and that the survival of oral Streptococci are more dependent on macrophage activation than other Gram positive microbes, both classical pathogens and commensals. We also find that S. gordonii-dependent inflammatory macrophage inflammasome activation requires the cytoplasmic NLRP6. Overall, our results suggest S. gordonii is capable of evading immune destruction, increasing inflammatory mediators, and increasing inflammatory macrophage response, and that this ability is increased under conditions of inflammation. This work reveals additional mechanisms by which normally commensal oral streptococci-macrophage interactions can change, resulting in increased release of mature IL-1β, potentially contributing to an environment that perpetuates inflammation.

TNF-α–TNFR1 Signaling Mediates Inflammation and Bone Resorption in Apical Periodontitis

IntroductionThe aim of this study was to investigate the role of the proinflammatory axis TNF-α–TNFR1 in experimentally induced periapical inflammation and bone resorption in mice. MethodsAfter receiving Ethics Committee Approval (2019.1.139.58.0), experimental apical periodontitis was induced by means of inoculating oral microorganisms into the root canals of molars of mice. Genetically deficient tumor necrosis factor-α receptor-1 mice (TNFR1-/-; n = 50) response was compared with that of C57Bl6 wild-type mice (wild-type; n = 50) after 7, 14, 28, and 42 days. The analyses performed were micro–computed tomographic, histopathologic, histomicrobiological, and histometric evaluation, tartrate-resistant acid phosphatase staining, immunohistochemistry, and quantitative reverse transcriptase polymerase chain reaction. Data were analyzed by using one-way analysis of variance, followed by Tukey or Bonferroni tests (α = 5%). ResultsTNFR1-/- mice exhibited lower recruitment of neutrophils at 14, 28, and 42 days (P < .05), which resulted in reduced area and volume of apical periodontitis at 42 days (P < .05). The number of osteoclasts was also lower in TNFR1-/- animals at 14 and 42 days (P < .01), along with reduced synthesis of CTSK, MMP-9, and COX-2. Expression of RANKL, but not OPG, was reduced at 14 and 42 days (P < .001). The highest RANKL expression over OPG (ratio > 1) was found in wild-type animals at 7 (P < .0001) and 42 days (P < .001). ConclusionsPeriapical inflammation and bone resorption were exacerbated in wild-type animals compared with TNFR1-/- mice, demonstrating that the TNF-α–TNFR1 signaling pathway mediated catabolic events in bone after root canal contamination.

Expression of Interleukin 17A and 17B in Gingival Tissue in Patients with Periodontitis.

Periodontitis (PD) is a chronic inflammatory disease that is initiated by oral microorganisms. The pathogens induce the production of cytokines, such as interleukin (IL)-17, which enhances the inflammatory response and progression of the disease. The aim of this study was to examine the expression and localization in gingival tissue of IL-17A and IL-17B in patients with periodontitis. This study included 14 patients with periodontal disease and 14 healthy subjects without periodontal disease as a control group. There were no statistically significant differences in the expression of IL-17A mRNA between patients with periodontitis and control subjects. The expression of IL-17B mRNA was statistically significantly lower in patients with periodontitis in comparison with healthy subjects (p < 0.048). The expression of IL-17A correlated significantly with the approximal plaque index. The IL-17B expression in gingival tissue correlated with the clinical attachment level. This correlation reached borderline statistical significance (p = 0.06). In immunohistochemical analysis, we have shown the highest expression of IL-17 protein in inflamed connective tissue, epithelium, and granulation tissue from gingival biopsy specimens from patients with periodontitis. In biopsy specimens from healthy individuals, no IL-17 was found in the epithelium, while an expression of IL-17 was found in the connective tissue. The results of our study confirm the involvement of IL-17 in the pathogenesis of periodontitis. Our results suggest that an increase in IL-17 protein expression in the gingival tissue of patients with periodontitis occurs at the post-translational stage.

The hypotheses of oral disease-associated perioprosthetic joint infections to understand the role of oral health for endoprostheses - a narrative review.

Periprosthetic infections are a severe complication, causing enormous morbidity. The role of oral diseases in the development of such infections has been discussed controversially, showing a large discrepancy between prevalence of oral foci and infections of endoprostheses (EP). This narrative review aimed in explaining and discussing two hypotheses for the occurrence of oral disease-associated EP infections. The hypotheses include two mechanisms. (1) In case of an acute exacerbation during the early healingperiod after EP surgery (first 3 months). (2) Coincidental in the context of late EP infections (after successful initial healing), where an initial periprosthetic inflammation can be colonized secondarily by oral microorganisms. In both settings,oral foci are not primarily causative for EP infection, but represent an important reservoir for EP colonization, while the immunological conditions (locally and systemically) are crucial for the onset of an EP infection. As potential consequence, patients with risk factors should be orally rehabilitated prior to EP surgery. Usage of antibiotic prophylaxis during the first 3 months after EP implantation (initial healing period) might be considered, but has no reliable evidence. To avoid morbidity of patients, radical dental clearance is unfavorable for the respective patients. Altogether, patients with EP should receive increased attention from the dental perspective alongside with dental preventive measures, because they show a high dental and periodontal treatment need.

The Study of the Cytotoxicity, Proliferative and Microbiological Activity of the Medicated Chewing Gum with Ascorbic Acid and Lysozyme Hydrochloride Using Different Culture of Cells.

Medicated chewing gum with lysozyme hydrochloride and ascorbic acid as active pharmaceutical ingredients was developed for application in dentistry. The aim of this research was to study the cytotoxicity, proliferative, and microbiological activities of the active ingredients in different types of cell cultures. The preclinical study of active pharmaceutical ingredients and their combinations was carried out using culture lines such as HepG2 (human hepatocarcinoma cells), Hek293 (human embryonic kidney cells), and MAEC (mouse aortic endothelial cells). MTT assays were used to analyse cytotoxicity and proliferative activity, while the state of antioxidant protection was assessed by the content of sulfhydryl groups and catalase activity. The determination of lipid peroxidation products was based on the level of TBA-active products. As a microbiological model for studying the effect of the developed dental medicine on the ability of the oral cavity microorganisms to form biofilms, the following strains were used: Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis, Lactobacillus plantarum, and Candida albicans. The optical density of the formed biofilm was evaluated by the intensity of the experimental sample's colour on a StatFax 303 Plus photometer at a wavelength of 630 nm. The combination of ascorbic acid and lysozyme hydrochloride in the established concentrations (20 mg and 10 mg per 1 gum, respectively) resulted in a slight stimulation of cell proliferation without any toxic effects and increased antioxidant protection, preventing the development of oxidative stress. It was found that, in contrast to the separately used active substances, the combination of lysozyme hydrochloride and ascorbic acid inhibits the biofilm formation of all studied microorganisms and shows the ability to destroy diurnal biofilms of L. plantarum and fungi of the genus Candida, indicating potentiation and summation of the active pharmaceutical ingredients' composition effects in the developed dental medicine. Due to the observed positive pharmacological and microbiological action, the combination of lysozyme hydrochloride and ascorbic acid in the medicated chewing gum serves as a promising tool for the prevention and treatment of infectious and inflammatory diseases of the periodontium and mucous membranes and the prevention of caries.

The Cell Biocompatibility of a new Polycaprolactone-based Endodontics Sealer Compared with AH Plus Sealer

Background:One of the important materials needed for root treatment is the sealers. They fill the space between the gutta and the canal walls and create a suitable seal to prevent the colonization of oral microorganisms in the peri-apical tissues and inside the canal space.Aim:The aim of this study was to prepare and test the cell biocompatibility of a new polycaprolactone-based endodontics sealer in comparison to AH plus sealer against dental pulp stem cells.Methods:MTT assay was used to evaluate the cytotoxicity.Results:The results showed that AH plus showed moderate cytotoxicity effects against cells (the number of living cells was 49.45 ± 10.56%). However, for the new sealer, the number of living cells was ≥ 80% (81% ± 4.11). Thus, the sample was non-cytotoxic against tested cells.Conclusion:More investigations are needed on the new sealer to validate its biocompatibility and usefulness.

The effect of sex steroid hormones on the ecology of in vitro oral biofilms

Sex steroid hormones (SSH) such as oestrogen, progesterone and testosterone are cholesterol derived molecules that regulate various physiological processes. They are present in both blood and saliva, where they come in contact with oral tissues and oral microorganisms. Several studies have confirmed the effect of these hormones on different periodontal-disease-associated bacteria, using single-species models. Bacteria can metabolize SSH, use them as alternative for vitamin K and also use them to induce the expression of virulence factors. However, it is still unclear what the effects of SSH are on the oral microbiome. In this study, we investigated the effects of four SSH on commensal in vitro oral biofilms. Saliva-derived oral biofilms were grown in Mc Bain medium without serum or menadione using the Amsterdam Active-Attachment model. After initial attachment in absence of SSH, the biofilms were grown in medium containing either oestradiol, oestriol, progesterone or testosterone at a 100-fold physiological concentration. Menadione or ethanol were included as positive control and negative control, respectively. After 12 days with daily medium refreshments, biofilm formation, biofilm red fluorescence and microbial composition were determined. The supernatants were tested for proteolytic activity using the Fluorescence Resonance Energy Transfer Analysis (FRET). No significant differences were found in biofilm formation, red fluorescence or microbial composition in any of the tested groups. Samples grown in presence of progesterone and oestradiol showed proteolytic activity comparable to biofilms supplemented with menadione. In contrast, testosterone and oestriol showed a decreased proteolytic activity compared to biofilms grown in presence of menadione.None of the tested SSH had large effects on the ecology of in vitro oral biofilms, therefore a direct translation of our results into in vivo effects is not possible. Future experiments should include other host factors such as oral tissues, immune cells and combinations of SSH as present in saliva, in order to have a more accurate picture of the phenomena taking place in both males and females.

Antimicrobial Assessment of Curcuma longa L Against Streptococcus mutans Growth

Background. Streptococcus mutans is the most common oral endogenous microorganism found at the beginning of plaque formation until the formation of dental caries. If not handled properly, caries can lead to odontogenic infections. Increased resistance to antimicrobial drugs has made herbal ingredients an alternative treatment because they are more effective and do not cause side effects. This turmeric leaf contains active antimicrobial compounds of flavonoids, tannins, and phenolics. Objective. This study aimed to determine the effectiveness of turmeric leaf extract (Curcuma longa. L) as an antimicrobial on the growth of Streptococcus mutans bacteria. Materials and Methods. This study uses a post-test-only control condition approach in a laboratory setting. The concentration of turmeric leaf extract tested was 10%, 15%, and 20% with the positive control (Chlorhexidine 0,2% mouthwash) and negative control (DMSO) with five repetitions. Antibacterial effectiveness test using serial dilution method. Results. The data analysis using the Oneway ANOVA test showed a p-value 0.05, meaning that the number of Streptococcus mutans bacterial colonies in both the treatment and control groups had a significant difference in number. The antibacterial effect at a 10% concentration of turmeric leaf extract (Curcuma longa. L) with an average and standard deviation of 45.20 ± 3.83, at a 15% concentration of 43.80 ± 3.11, at a 20% concentration of 23.60 ± 12.30. Conclusion. This study concludes that turmeric leaf extract (Curcuma longa. L) has antibacterial effectiveness against Streptococcus mutans bacteria.Keywords: Curcuma longa L, Turmeric Leaf, Streptococcus mutans, Antibacterial

Antagonistic Interactions of Lactic Acid Bacteria from Human Oral Microbiome against Streptococcus mutans and Candida albicans.

Oral probiotic lactic acid bacteria can exhibit antagonistic activities against pathogens associated with diseases in the oral cavity. Therefore, twelve previously isolated oral strains were assessed for antagonistic evaluation against selected oral test microorganisms Streptococcus mutans and Candida albicans. Two separate co-culturing analyses were performed, where all tested strains showed the presence of antagonistic activity and four strains, Limosilactobacillus fermentum N 2, TC 3-11, and NA 2-2, and Weissella confusa NN 1, significantly inhibited Streptococcus mutans by 3-5 logs. The strains showed antagonistic activity against Candida albicans, and all exhibited pathogen inhibition by up to 2 logs. Co-aggregation capability was assessed, showing co-aggregative properties with the selected pathogens. Biofilm formation and antibiofilm activity of the tested strains against the oral pathogens were assayed, where the strains showed specificity in self-biofilm formation and well-expressed antibiofilm properties by most of them above 79% and 50% against Streptococcus mutans and Candida albicans, respectively. The tested LAB strains were assayed by a KMnO4 antioxidant bioassay, where most of the native cell-free supernatants exhibited total antioxidant capacity. These results show that five tested strains are promising candidates to be included in new functional probiotic products for oral healthcare.

Extracts from the Leaf of Couroupita guianensis (Aubl.): Phytochemical, Toxicological Analysis and Evaluation of Antioxidant and Antimicrobial Activities against Oral Microorganisms.

The study of phytotherapy in dentistry holds great relevance because of the scarcity of research conducted on the treatment of oral pathologies, specifically, caries and periodontal disease. Therefore, this research aimed to analyze the chemical composition of extracts from Couroupita guianensis Aubl. leaves, evaluate their toxicity, and assess their antioxidant and antimicrobial properties against Staphylococcus aureus, Streptococcus mutans, and Candida albicans. Three extracts were prepared using assisted ultrasound and the Soxhlet apparatus, namely, Crude Ultrasound Extract (CUE), Crude Soxhlet Extract (CSE), and the Ethanol Soxhlet Extract (ESE). Flavonoids, tannins, and saponins were detected in the chemical analysis, while LC-DAD analysis revealed the presence of caffeic acid, sinapic acid, rutin, quercetin, luteolin, kaempferol, and apigenin in all extracts. GC-MS analysis identified stigmasterol and β-sitosterol in the CUE and CSE. The ESE showed higher antioxidant activity (2.98 ± 0.96 and 4.93 ± 0.90) determined by the DPPH• and ABTS•+ methods, respectively. In the toxicity evaluation, the CUE at 50 μg/mL and the ESE at 50 μg/mL stimulated the growth of Allium cepa roots, while all extracts inhibited root growth at 750 μg/mL. None of the extracts exhibited toxicity against Artemia salina. Antibacterial activity was observed in all extracts, particularly against the microorganisms S. aureus and S. mutans. However, no antifungal activity against C. albicans was detected. These results suggest that extracts of C. guianensis have therapeutic potential for controlling microorganisms in the oral microbiota.

Disinfection of 3D-printed surgical guides using virgin coconut oil (in vitro study)

Background/objectiveDisinfection of a 3D-printed surgical guide is of utmost importance as it comes into contact with hard and soft tissue during implant placement so it poses a potential risk of pathogenic transmission. Methods used for disinfection in the surgical field should be reliable, practical, and safe for the instruments and the patients. The objectives of this study were to compare the antimicrobial potential of 100% Virgin Coconut Oil, 2% Glutaraldehyde, and 70% Ethyl Alcohol used to decontaminate 3D-printed surgical guides.Materials and methodsThirty identical surgical guides were printed and cut into two halves (N = 60). Both halves were then contaminated with a defined amount of human saliva samples (2 ml). The first half (n = 30) was sub-grouped into three study groups which were immersed in one of the three disinfectants for 20 min as follows; group VCO was immersed in 100% Virgin Coconut Oil, group GA was immersed in 2% Glutaraldehyde, and group EA was immersed in 70% Ethyl Alcohol. The second half (n* = 30) was sub-grouped into three control groups which were immersed in sterile distilled water as follows group VCO*, group GA*, and group EA*. The microbial count was expressed as colony-forming units per plate and the comparison of the antimicrobial potential of the three tested disinfectants between the three study and three control groups was done using the One-Way ANOVA test.ResultsThe culture results of three study groups revealed no bacterial growth with the highest % of reduction in the mean microbial count of the oral microorganisms (about100%) and an uncountable bacterial growth was shown between the three control groups (more than 100 CFU/plate) representing the baseline of the oral microorganisms. Therefore; statistically significant differences were found between the three control and three study groups (P < .001).ConclusionThe antimicrobial potential of Virgin Coconut Oil was comparable and equivalent to Glutaraldehyde and Ethyl Alcohol with a significant inhibitory action against oral pathogens.

TLR3 recognition of viral double-stranded RNA in human dental pulp cells is important for the innate immunity

Dental caries or trauma can expose human dental pulp cells (DPCs) to various oral microorganisms, which play an important role in the development of an innate immune response. In the present study, we examined the expression of Toll-like receptors (TLRs) for sensing microbe-associated molecular patterns in human DPCs. Interestingly, real-time PCR analysis demonstrated that TLR3 is the most highly expressed among 10 different TLRs in human DPCs. Poly(I:C), a representative TLR3 ligand mimicking viral double-stranded RNA, potently induced IL-8 expression in a time- and dose-dependent manner. Concordantly, poly(I:C) treatment substantially increased the expression of pro-inflammatory cytokines and chemokines such as IL-6, CCL2, and CXCL10. Human DPCs transfected with TLR3 siRNA exhibited decreased IL-8 production compared with non-targeting siRNA-transfected cells, suggesting that the expression of poly(I:C)-induced inflammatory cytokines is dependent on TLR3. IL-8 secretion induced by poly(I:C) was down-regulated by MAP kinase inhibitors, indicating that the MAP kinase pathway contributes to IL-8 production. Furthermore, C/EBPβ and NF-κB were essential transcriptional factors for poly(I:C)-induced IL-8 expression, as demonstrated by the transient transfection and reporter gene assay. Since lipoproteins are known as major immunostimulatory components of bacteria, human DPCs were treated with poly(I:C) together with Pam2CSK4, a synthetic lipopeptide mimicking bacterial lipoproteins. Pam2CSK4 and poly(I:C) co-treatment synergistically increased IL-8 production in comparison to Pam2CSK4 or poly(I:C) alone, implying that co-infection of viruses and bacteria can synergistically induce inflammatory responses in the dental pulp. Taken together, these results suggest that human DPCs potentially sense and respond to viral double-stranded RNAs, leading to effective induction of innate immune responses.

Effectiveness of Aspergillus sp. extract in denture adhesive on surface roughness of acrylic resin on Candida albicans biofilm formation

The denture adhesive increases retention on the denture base and affects oral microorganisms. Adding antifungals to denture adhesives can inhibit the Candida albicans biofilms formation and prevent denture stomatitis. The combination of denture adhesives and herbal medicines is an alternative to antifungals, which have few side effects because it is a plant. Moreover, one of them is the endophytic Aspergillus sp. extract containing chemical compounds that can inhibit the Candida albicans biofilms formation. This study aims to analyze the effectiveness of the endophytic Aspergillus sp. extract in denture adhesive materials for Candida albicans biofilm formation on acrylic resin surfaces. The research method is to extract the Aspergillus sp. extract antibiofilm test. Denture adhesive formulation was adjusted to the standard, and added Aspergillus sp. with concentrations of 3.125%, 6.25%, 12%, and 25%. The research sample used hot polymerized acrylic resin. The control group used X denture adhesive and added nystatin, each group suspended by Candida albicans for 24, 48, and 72 hours. Examination of biofilm formation activity on the surface of acrylic resin used SEM. The analysis used Two Way Anova. Aspergillus sp. extract in denture adhesive effectively prevents Candida albicans biofilm formation within 24 hour incubation time. In conclusion, extract of the endophytic Aspergillus sp. in denture adhesive can inhibit the formation of Candida albicans biofilm on the surface roughness of acrylic resin.

Factors influencing microbial growth in the human oral cavity

The human oral cavity is a significant contact point for diverse microbes. It allows frequent entry and exit of microbes through inhalation, exhalation, drinks, spitting, and consuming foods. The environmental conditions inside the cavity influence the selection, growth, and development of microbial communities. The conditions, in turn, are probably because of complex interaction and activities of various molecules of host and residential microbes. Further, oral ecology is influenced by the food habit of individuals and the community. The community of microorganisms may shift gradually or spontaneously depending on the physicochemical environment in the cavity. The presence of a group of organisms along with the food habit jointly may indicate the probable microbes succeeding. Understanding the relation complexity among the physiochemical nature of the oral cavity, the resident microbes, and individuals’ food habits may decipher the microbes to be attracted for succession. This review is for understanding the factors that influence the occurrence and refusal of oral microorganisms.

Rapid specific detection of oral bacteria using Cas13-based SHERLOCK

ABSTRACT Decades of ongoing research has established that oral microbial communities play a role in oral diseases such as periodontitis and caries. Yet the detection of oral bacteria and the profiling of oral polymicrobial communities currently rely on methods that are costly, slow, and technically complex, such as qPCR or next-generation sequencing. For the widescale screening of oral microorganisms suitable for point-of-care settings, there exists the need for a low-cost, rapid detection technique. Here, we tailored the novel CRISPR-Cas-based assay SHERLOCK for the species-specific detection of oral bacteria. We developed a computational pipeline capable of generating constructs suitable for SHERLOCK and experimentally validated the detection of seven oral bacteria. We achieved detection within the single-molecule range that remained specific in the presence of off-target DNA found within saliva. Further, we adapted the assay for detecting target sequences directly from unprocessed saliva samples. The results of our detection, when tested on 30 healthy human saliva samples, fully aligned with 16S rRNA sequencing. Looking forward, this method of detecting oral bacteria is highly scalable and can be easily optimized for implementation at point-of-care settings.

Green synthesis, characterization, and antibacterial activity of Citrus lanatus based silver nanoparticles.

Due to their enhanced and unique physicochemical characteristics, such as their minimal dimensions, large surface area compared to their mass and increased reactivity, nanomaterials hold promise in the field of antibacterial therapy. The aim of this study is to evaluate the method for Green Synthesis, Characterization of Citrus lanatus pulp, rind, and seed-based Silver Nanoparticles, and study its antibacterial activity against common oral microorganisms. Green synthesis of nanoparticles was formulated using the extract from the rind, seed, and pulp of Citrullus lanatus and silver nitrate extract. The extract was stirred in a magnetic stirrer for 24 hours, and centrifugation was done at 8000 rpm for 10 minutes. The synthesized nanoparticles were characterized and utilized for the antibacterial study. The characterization was done using UV-visible light spectroscopy, and antibacterial activity was assessed using the well diffusion method and measuring the zone of inhibition. The nanoparticles synthesized were characterized using UV-visible spectroscopy, and the spectroscopic analysis confirmed the formation of silver particles in this study. At 450 nm, a sharp peak was observed, which correlated to the SPR band of the particles. The results showed that the zone of inhibition assessed was comparable to the standard. From this study it can be concluded that silver nanoparticles (AgNPs) produced by green synthesis from Citrullus lanatus showed significant antibacterial potential against common oral microflora.

Characterization of the Oral Microbiome in Wearers of Fixed and Removable Implant or Non-Implant-Supported Prostheses in Healthy and Pathological Oral Conditions: A Narrative Review.

Oral commensal microorganisms perform very important functions such as contributing to the health of the host. However, the oral microbiota also plays an important role in the pathogenesis and development of various oral and systemic diseases. The oral microbiome may be characterized by a higher prevalence of some microorganisms than others in subjects with removable or fixed prostheses, depending on oral health conditions, the prosthetic materials used, and any pathological conditions brought about by inadequate prosthetic manufacturing or poor oral hygiene. Both biotic and abiotic surfaces of removable and fixed prostheses can be easily colonized by bacteria, fungi, and viruses, which can become potential pathogens. The oral hygiene of denture wearers is often inadequate, and this can promote oral dysbiosis and the switch of microorganisms from commensal to pathogens. In light of what emerged from this review, fixed and removable dental prostheses on teeth and on implants are subject to bacterial colonization and can contribute to the formation of bacterial plaque. It is of fundamental importance to carry out the daily hygiene procedures of prosthetic products, to design the prosthesis to facilitate the patient's home oral hygiene practices, and to use products against plaque accumulation or capable of reducing oral dysbiosis to improve patients' home oral practices. Therefore, this review primarily aimed to analyze the oral microbiome composition in fixed and removable implant or non-implant-supported prostheses wearers in healthy and pathological oral conditions. Secondly, this review aims to point out related periodontal self-care recommendations for oral dysbiosis prevention and periodontal health maintenance in fixed and removable implant or non-implant-supported prostheses wearers.

Simultaneous vegetation of opportunistic oral microorganisms in chronic periodontitis with recurrent course

Aim. To evaluate clinical significance of simultaneous vegetation by conducting microbiological research of the species composition in the periodontal pockets and on the surface of the tongue root and back in chronic (generalized) periodontitis.Materials and methods. A prospective microbiological analysis of clinically significant species of opportunistic microorganisms in pathological periodontal pockets and the microbiome of the tongue root and back, in chronic (generalized) periodontitis of mild, moderate and severe degree, was carried out in 88 patients of the WHO key group, aged 35–44 (CI 95% 34.8–44.3), of the Unistom Dental Clinic of the Far Eastern State Medical University, Khabarovsk Krai, for the period 2016–2019.Results. The species composition of opportunistic microorganisms in the biotopes of the pathological periodontal pockets and tongue root and back was the same in chronic periodontitis, with a mean value of 89.7% ±2.9% (CI 95% 85.8–94.4). The mean value of the number of species of clinically significant opportunistic microorganisms in the periodontal pockets and root and back of the tongue in associations accounted for 3.9 (CI 95% 1.8–5.4). Bacteria of the genus Leptotrichia were detected simultaneously in periodontal pockets and on the root and back of the tongue in clinically significant associations with Staphylococcus aureus (CI 95% 37.3–65.4), mean Shannon index H value 3.1 ± 0.4; mean Simpson index C value 0.39 ± 0. Bacteria of the genus Leptotrichia in association with Streptococcus pyogenes (CI 95% 35.8–79.3), mean Shannon index H 2.9 ± 0.3; mean value of the Simpson index C 0.28 ± 0.06, reliably support the recurrent course of the opportunistic infectious and inflammatory process in the periodontium. The dominant role of Staphylococcus aureus and Streptococcus pyogenes in the biotopes of periodontal pockets and the root and back of the tongue in exacerbations of chronic periodontitis has been established. Titre of opportunistic microorganisms in pathological periodontal pockets of 2–5lgCFU (colony-forming units) in mild and moderate degree of severity is 1–2 order lower than titre of opportunistic microorganisms in root and back of the tongue of 4–6lgCFU (95% CI 2.1–6.5).Conclusions. Evaluation of simultaneous vegetation of opportunistic microorganisms in the oral microbiome provides a means for improving laboratory (microbiological) diagnostics in chronic periodontitis and applying a non-invasive microbiological method for indirect diagnosis of the species composition of opportunistic microorganisms in periodontal pockets according to the composition of opportunistic microorganisms of the root and back of the tongue in chronic periodontitis for prophylaxis and treatment personalization.

The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment: a systematic review and meta-analysis

BackgroundMouthwashes were convenient adjuncts to mechanical cleaning procedures. This review aimed to evaluate the efficacy of mouthwashes on oral microorganisms and gingivitis in orthodontic patients.MethodsBy April 16, 2022, multiple databases and grey literature were searched based on the PICOS strategy. Randomized controlled trials in orthodontic patients evaluating the efficacy of mouthwashes with at least one microbial parameter and/or plaque- and/or gingival inflammation-related index were included. Relevant data were extracted, and the risk of bias was evaluated using Cochrane's tool. Individual mean and standard deviation of the outcomes in mouthwashes and placebos/blank controls were pooled to estimate the weighted mean differences (WMDs) and 95% confidence intervals (95%CIs). Sensitivity analysis, and certainty of evidence were evaluated.ResultsOf 1684 articles, 32 studies satisfied the eligibility criteria, and nine were included for meta-analysis. Missing outcome data was the primary source of bias. Compared to blank controls, the short-term application of fluoride mouthwashes significantly reduced the colony counts of Mutans streptococci (MS), while the long-term application may not be effective. Compared to placebos or blank controls, Chlorhexidine mouthwashes significantly reduced the colony counts of multiple microorganisms in the short-term. Compared to placebos or blank controls, herbal mouthwashes showed the inhibitory effect of MS in the short-term, with some results lacking statistical significance. After meta-analysis, significant lower plaque- and gingival inflammation-related indexes were observed in the Chlorhexidine mouthwashes groups [Gingival Index: WMD = -0.45, 95%CI = -0.70 to -0.20 (placebos as control); WMD = -0.54, 95%CI = -0.96 to -0.13 (blank controls); Plaque Index: WMD = -0.70, 95%CI = -1.12 to -0.27 (blank controls)]. Significant lower gingival inflammation-related indexes were observed in the herbal mouthwashes groups [Gingival Index: WMD = -0.20, 95%CI = -0.32 to -0.09 (blank controls)].ConclusionsThe short-term application of fluoride mouthwashes may reduce the colony counts of cariogenic bacteria, but the long-term effect is not evident. Chlorhexidine may reduce the colony counts of multiple microorganisms in the short-term. Short-term application Chlorhexidine and herbal mouthwashes may effectively reduce plaque- and gingival inflammation-related indexes. However, the risk of bias, inconsistency, and imprecision in the included studies may reduce the certainty of the evidence.