Impact of sleep on the microbiome of oral biofilms

Dysbiosis of the oral microbiome is associated with diseases such as periodontitis and dental caries. Because the bacterial counts in saliva increase markedly during sleep, it is broadly accepted that the mouth should be cleaned before sleep to help prevent these diseases. However, this practice does not consider oral biofilms, including the dental biofilm. This study aimed to investigate sleep-related changes in the microbiome of oral biofilms by using 16S rRNA gene sequence analysis. Two experimental schedules—post-sleep and pre-sleep biofilm collection—were applied to 10 healthy subjects. Subjects had their teeth and oral mucosa professionally cleaned 7 days and 24 h before sample collection. Samples were collected from several locations in the oral cavity: the buccal mucosa, hard palate, tongue dorsum, gingival mucosa, tooth surface, and saliva. Prevotella and Corynebacterium had higher relative abundance on awakening than before sleep in all locations of the oral cavity, whereas fluctuations in Rothia levels differed depending on location. The microbiome in different locations in the oral cavity is affected by sleep, and changes in the microbiome composition depend on characteristics of the surfaces on which oral biofilms form.

A Rare Case of Angiofibroma Mimicking Fibrous Epulis in Posterior Gingival Mucosa

Angiofibromas are highly vascular, locally aggressive but histologically benign tumors. A 40-year-old woman complaint of pedunculated mass in the right gingiva of the posterior region since 7 months earlier. Surgical excisional biopsy under general anesthesia was performed. Histopathological examination showed an angiofibroma. Angiofibromas are localized in the superficial soft tissue and the gingiva could have a similar clinical appearance as an epulis. Definitive diagnosis was determined through histopathological analysis.

Correlation Between Clinical and Histopathological Diagnoses in Oral Cavity Lesions: a 12-year Retrospective Study

Background: Proper diagnosis plays key roles in the treatment and prognosis of all diseases. Although histopathological diagnosis is still known as the gold standard, final diagnosis becomes difficult unless precise clinical descriptions are obtained. So, this study aimed to evaluate the consistency of the clinical and histopathological diagnoses of all oral and maxillofacial biopsy specimens in a 12–year duration.Methods: After receiving the ethical approval from Shiraz University of Medical Sciences, archive files and clinical findings related to 3001 patients who had been referred to the Department of Oral Pathology during a 12-year period, were reviewed. The recorded information in files included age, sex, lesion’s location, clinical and histopathological diagnoses, and specialty of dentists.Results: Out of 3001 cases included and reviewed in this study, 2167 cases (72.2%) were consistent between clinical and histopathologic diagnoses. The highest frequency of oral lesions was found in the mandibular bone and the lowest one was in the floor of mouth. Age, sex, and clinician’s specialty were indicated to have no significant effect on diagnosis (p> 0.05), but location and type of lesion affected that (p <0.05). In regard to location, the highest consistency of clinical and histopathologic diagnoses was observed in mouth floor lesions and the lowest one was in gingival mucosa. In terms of lesion category, the highest and the lowest consistency rates belonged to white and red lesions and pigmented lesions, respectively.Conclusions: The results of the present study show that the consistency of clinical and histopathological diagnoses was three times more than their inconsistency, and the accuracy of the clinicians was largely acceptable.

The inhibitory effects of toothpaste and mouthwash ingredients on the interaction between the SARS-CoV-2 spike protein and ACE2, and the protease activity of TMPRSS2 in vitro

SARS-CoV-2 enters host cells when the viral spike protein is cleaved by transmembrane protease serine 2 (TMPRSS2) after binding to the host angiotensin-converting enzyme 2 (ACE2). Since ACE2 and TMPRSS2 are expressed in the tongue and gingival mucosa, the oral cavity is a potential entry point for SARS-CoV-2. This study evaluated the inhibitory effects of general ingredients of toothpastes and mouthwashes on the spike protein-ACE2 interaction and the TMPRSS2 protease activity using an in vitro assay. Both assays detected inhibitory effects of sodium tetradecene sulfonate, sodium N-lauroyl-N-methyltaurate, sodium N-lauroylsarcosinate, sodium dodecyl sulfate, and copper gluconate. Molecular docking simulations suggested that these ingredients could bind to inhibitor-binding site of ACE2. Furthermore, tranexamic acid exerted inhibitory effects on TMPRSS2 protease activity. Our findings suggest that these toothpaste and mouthwash ingredients could help prevent SARS-CoV-2 infection.

Comparison of the Therapeutic Potential of Rat and Human Mesenchymal Stromal Cells and Their Conditioned Media in Local Radiation Lesions

Background: To compare the results of the use of mesenchymal stromal cells (MSCs) of human gingival mucosa and MSCs of rat gingival mucosa, their conditioned media, and to evaluate their effect on tissue regeneration in local radiation injury (LRI). Material and methods: The study included 120 white male Wistar rats weighing 210 ± 30 g at the age of 8–12 weeks, randomized into 6 groups (20 animals each): control (C), animals did not receive therapy; control with the introduction of culture medium concentrate (CM) three times for 1, 14, 21 days; administration of human gingival mucosa MSCs (HM) at a dose of 2 million per 1 kg three times for 1, 14, 21 days; administration of human gingival mucosa MSCS conditioned medium concentrate (HMCM) at a calculated dose of 2 million cells per 1 kg three times for 1, 14, 21 days; administration of rat gingival mucosal MSCs (RM) at a dose of 2 million cells per 1 kg three times for 1, 14, 21 days; administration of rat gingival mucosal MSCS (RMCM) conditioned medium concentrate at a calculated dose of 2 million cells per 1 kg three times for 1, 14, 21 days. Each laboratory animal was observed 17 times: on 1, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112 day after the burn simulation. Histological (hematoxylin-eosin staining) and immunohistochemical (CD31, CD68, VEGF, PGP 9.5, MMP2,9, Collag 1, TIMP 2) studies were performed. LRI was modeled on an X-ray machine at a dose of 110 Gy. MSCs were cultured according to the standard method up to 3–5 passages, the conditioned medium was taken and concentrated 10 times. The immunophenotype of MSCs (CD34, CD45, CD90, CD105, CD73, HLA-DR) and viability (7‑ADD) were determined by flow cytofluorimetry. Results: In a comparative analysis with the control group (C), starting from the 42nd day of the study, a tendency to reduce the area of skin ulcers in animals in all groups was observed, despite the fact that not all days had statistically significant differences. On day 112th, complete healing of skin ulcers in the CM group was observed in 40 % of animals in the HM group – in 60 %, in the HMCM group – in 20 % of animals, in the RMCM group–20 %, and in the C and RM groups there were no animals with a prolonged wound defect. Positive expression of the VEGF marker was observed in groups C and CM on the 28th day and in experimental groups (HM, HMCM, RM, RMCM) on the 112th day. A statistically significant increase in the CD68 marker was observed in groups C, RM, and RMCM, while the remaining groups showed a decrease in the number of macrophages.

Clinical and pathogenetic significance of the gingival microbiota in rheumatoid arthritis

Background. The trigger factors of the development of rheumatoid arthritis (RA) may be infections associated with the carriage in the oral cavity of Actinomycetes, Campylobacter, Mycoplasma, Porphyromonas, Transducers, Proteus, Selemons, Streptococci, and Fusobacteria, but their role in the disease pathogenesis requires clarification. In turn, the quantity of cases of comorbid infectious pathology significantly increases in RA. The purpose was to study the qualitative and quantitative composition of the oral microbiota in RA, to assess the role of individual bacteria in the pathogenetic structures of the disease. Materials and methods. There were examined 121 RA patients aged 18–76 years (on ave­rage 49 years old), among whom there were 19 % men and 81 % women. The duration from the first manifestation of the disease averaged 10 years. The frequency of seropositivity of RA for rheumatoid factor in the blood was 81 %, and for antibodies to cyclic citrullinated peptide — 75 %. I, II, and III degrees of disease activity were determined in 13, 45, and 42 % of cases, respectively, and the ratio of I, II, III, and IV stages of the pathological process was 1 : 5 : 5 : 3. To assess the number of aerobic and facultative anaerobic microorganisms growing on the gingival mucosa, the technique of sterile paper discs was used. The kits “Mikro-La-Test”, “Streptotest-16”, “Anaero-Test 23”, “Neferm Test 24” were used. Results. The vegetation of associations of aerobes on the gums was found in 96.7 % of patients, anaerobic bacteria — in 91.7 %, the number of which is closely related to clinical, laboratory, and X-ray signs of RA, while the integral landscape of the gingival microbiota is influenced by the severity of the comorbid chronic generalized periodontitis, which affects the presence of Moraxella, Sarcina, Streptococci, and Eubacteria in the oral cavity, moreover, the number of anaerobes reflects the degree of RA activity and bone mineral density, and in the pathogenetic constructions of individual signs of the disease (the nature of the articular syndrome and damage to the periarticular tissues), Aerococci, Candida, Clostridia, Megasphaera, Propionibacteria, Sarcina, Fusobacteria, and Eubacteria are involved. Conclusions. The obtained data dictate the need to develop new approaches to medical techno­logy for individual etiopathogenetic therapy of RA with comorbid periodontitis, to identify criteria that allow assessing the activity of the pathological process, predicting the nature of the course of the disease and the effectiveness of therapeutic measures.

Single-cell atlas of human oral mucosa reveals a stromal-neutrophil axis regulating tissue immunity in health and inflammatory disease

The oral mucosa remains an understudied barrier tissue rich in exposure to antigens, commensals and pathogens. Moreover, it is the tissue where one of the most prevalent human microbe-triggered inflammatory diseases, periodontitis, occurs. To understand this complex environment at the cellular level, we assemble herein a human single-cell transcriptome atlas of oral mucosal tissues in health and periodontitis. Our work reveals transcriptional diversity of stromal and immune cell populations, predicts intercellular communication and uncovers an altered immune responsiveness of stromal cells participating in tissue homeostasis and disease at the gingival mucosa. In health, we define unique populations of CXCL1,2,8- expressing epithelial cells and fibroblasts mediating immune homeostasis primarily through the recruitment of neutrophils. In disease, we further observe stromal, particularly fibroblast hyper-responsiveness linked to recruitment of leukocytes and neutrophil populations. Ultimately, a stromal-neutrophil axis emerges as a key regulator of mucosal immunity. Pursuant to these findings, most Mendelian forms of periodontitis were shown to be linked to genetic mutations in neutrophil and select fibroblast-expressed genes. Moreover, we document previously unappreciated expression of known pattern- and damage- recognition receptors on stromal cell populations in the setting of periodontitis, suggesting avenues for triggering stromal responses. This comprehensive atlas offers an important reference for in-depth understanding of oral mucosal homeostasis and inflammation and reveals unique stromal-immune interactions implicated in tissue immunity.

Intensity and duration of phases of wound healing after surgical intervention in сases of spontaneous periodontitis accompanied by various reactivity of the body

The usage of the principle of optimal management, namely such effects on complicated forms, when the course of the disease is close to that of uncomplicated course of the disease is very promising in drug therapy of patients with generalized periodontitis. The aim is to study the intensity and duration of the phases of wound healing of the mucosa after spontaneous periodontitis surgery accompanied by normo-, hyper- and hyporeactivity of the body by cytological examination of smear-imprints of wound exudate. Materials and methods: The experiments were performed on 24 adult mongrel dogs divided into three equal groups. In the first group, drugs that disrupt the reactivity of the organism were not used (normoreactivity of the organism). In the second group, the animals were simulated a сondition of hyperreactivity, in the third group – the hyporeactivity of the organism. All the animals with spontaneous periodontitis underwent a patchwork surgery. In the period after surgery, cytological examination was performed on the 1st, 4th, 6th and 9th day of the experiment. Results: It has been revealed that in cases of the normal reactivity of the organism the following periods of cellular reactions during the healing of the gums mucous membrane can be differentiated within the appropriate terms: the period of degenerative-inflammatory changes (1st day), active granulocyte-macrophage reaction (4th day), reparations (6th day) and the period of increase of reparative processes with a decrease in the overall cellular response (9th day). Examination of smear-imprints after surgical treatment in animals with spontaneous periodontitis with hyper- and hyporeactivity of the body allowed to identify the same periods of cellular reactions during the healing of the gingival mucosa, as in cases of normoreaction with hyperreation.Tthe intensity and duration of the wound healing phases differed from those which are typical for normoreactivity of the body: granulocyte-macrophage reaction was more pronounced and lasted longer until the 6th day, so later only on the 9th day there were cellular signs of regeneration. With hyporeaction, the intensity and duration of the wound healing phases differed from those which are typical for normoreactivity of the body: granulocyte reaction occurred later (only on the 6th day) and lasted longer, signs of active regeneration appeared later on the 9th day. Therefore, postoperative wound healing in animals with impaired body reactivity was delayed for 3-4 days. Conclusions: Thus, direct medical correction with transforming intensity and duration of the phases of the wound process which are characteristic for impaired reactivity of the body into the phases which are typical for normoreaction is essential. It provides synchronization of necrotic and reparative processes and creates conditions for normal uncomplicated healing of periodontal soft tissues

Clinical and pathogenetic features of the joint syndrome in rheumatoid arthritis with comorbid periodontitis

Background. The accumulation of bacteria in the oral cavity of patients with rheumatoid arthritis (RA) increases the incidence of periodontal tissue lesions, but there is also an inverse relationship between both diseases when comorbid periodontitis contributes to the occurrence of RA. Endotoxemia caused by periodontitis can increase the sensitivity of RA patients to autoantigens and participate in the pathogenetic structures of both diseases. RA and periodontitis have similar osteoclasia, allelic genes, and a general imbalance in the state of the cytokine network. The purpose and objectives of the study: to study the frequency and nature of the course of comorbid chronic generalized periodontitis in patients with RA, to determine its etiological factors, to assess the degree of its influence on clinical and X-ray sonographic signs of the articular syndrome. Material and methods. The study included 173 RA patients aged 18–76 years (average 46 years), among whom there were 20.8 % men and 79.2 % women. The duration from the disease onset averaged 10 years. The frequency of seropositivity of RA for rheumatoid factor in the blood was 74.6 %, and for antibodies to citrulline cyclic peptide — 72.8 %. The I, II, and III degrees of disease activity, respectively, were determined in 26.0, 43.9, and 30.1 % of cases, and the ratio of I, II, III, and IV stages of the pathological process was 1 : 6 : 5 : 3. To assess the number of aerobic and facultative anaerobic microorganisms vegetating on the gingival mucosa, the method of sterile paper discs was used. Clinical, X-ray and ultrasound examination of the joints, a study of biochemical, enzyme-linked immunosorbent and physicochemical parameters of blood and oral washings, determination of the integral severities of the underlying and comorbid pathology were carried out. Results. Chronic generalized periodontitis was diagnosed in 45.7 % of RA patients (the ratio of men to women is 1 : 4), the development of which was closely related to the activity and stage of articular syndrome, the presence of systemic osteoporosis, seropositivity of the disease for rheumatoid factor and antibodies to cyclic citrulline peptide, and in the etiology of periodontitis, Moraxella, Pseudomonas, Staphylococci, Streptococci, Bacterioids, Eubacteria, Fusobacteria, Propionibacteria, and Sarcina are of paramount importance, and in its pathogenesis — interleukin 1β. At the same time, the pathology of the oral cavity itself is involved in the pathogenetic constructions of osteoporosis, lesions of the maxillary, wrist, and knee joints, the formation of arthrocalcifications, and the development of Sjogren’s syndrome. Conclusions. The obtained data dictate the need to develop new approaches to medical technology of individual pathogenetic therapy of RA, taking into account the presence and etiology of comorbid periodontitis, identifying criteria that allow assessing the activity of the pathological process, predicting the nature of the course of the disease and the effectiveness of therapeutic measures.

PHYSICS AND CHEMICAL, IMMUNOENZYME AND BIOCHEMICAL INDICATORS OF ORAL FLUID IN PERIODONTITIS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Infection with comorbid periodontitis due to transient bacteremia in patients with rheumatoid arthritis (RA) can lead to microbial colonization outside the mouth and increase systemic immune inflammation. Periodontitis-induced endotoxemia increases the sensitivity of RA patients to autoantigens by activating membrane proteins, pro-inflammatory enzymes, and cytokines. RA and periodontitis have similar osteoclasia, allelic genes and general imbalance in the state of the cytokine network, and carbamylation of proteins and the formation of extracellular traps of neutrophils are associated with simultaneous autoimmune imbalance in the combination of RA and periodontitis, but the listed pathogenetic mechanisms require further study. The purpose and objectives of the study: to study the properties of the oral fluid in periodontitis in patients with RA, to determine the clinical and pathogenetic significance of changes in physicochemical, enzyme immunoassay and biochemical parameters in the pathology of the oral cavity and joints, to compare the indicators with the nature of the gingival microbiota. Material and methods. The study included 173 RA patients aged 18-76 years (average 46 years), among whom there were 21% of men and 79% of women. The duration from the first manifestation of the disease averaged 10 years. The frequency of RA seropositivity for rheumatoid factor in the blood was 75%, and for antibodies to citrulline cyclic peptide was 73%. The І, ІІ and ІІІ degrees of disease activity, respectively, were stated in 26%, 44% and 30% of cases, and the ratio of I, II, III and IV stages of the pathological process was 1: 6: 5: 3. Results. We studied the physicochemical adsorption-rheological properties of the oral fluid (surface tension, viscoelasticity, relaxation), the levels of pro-inflammatory cytokines in it, the concentration of aminopeptide, peptide, nucleotide and chromatophore fractions of average weight molecules, the ratio with similar parameters in blood serum. To assess the number of aerobic and facultative anaerobic microorganisms vegetating on the gingival mucosa, the method of sterile paper discs was used. Compared with healthy people in the control group, 99% of the number of RA patients has an increase in the concentration of interleukin 1b in the oral fluid (22 times), 98% of tumoronecrotic factor a (7 times), 43% of the average increase in the average weight molecules (by 47%), at the same time, the parameters are associated with the presence of secondary Sjogren's syndrome, with the severity of the course of both articular syndrome, and periodontitis, which is accompanied by a longer relaxation time of oral washings (by 36%), but their lower interfacial activity (by 11%), the ratio of the tumor necrosis factor parameter a with the level of this pro-inflammatory cytokine in the blood (by 70%), and there are dispersion relationships of individual indicators of the oral fluid with the vegetation on the gums of bacterioids, bifidobacteria, Escherichia coli, megaspheres, moraxellas, neisseria, propionibacteria, proteus, pseudomones, sarcins and streptococcus. Conclusions: the obtained data dictate the need to develop new approaches to medical technology for individual pathogenetic therapy of chronic generalized periodontitis, taking into account its etiology in RA patients, identifying criteria that allow assessing the activity of the pathological process, predicting the nature of the course of the disease and the effectiveness of treatment measures.