In Vitro Effects of Silver Nanoparticles on Pathogenic Bacteria and on Metabolic Activity and Viability of Human Mesenchymal Stem Cells.

The rapid development of nanotechnology has led to the use of silver nanoparticles (Ag-NPs) in various biomedical fields. However, the effect of Ag-NPs on human mesenchymal stem cells (hMSCs) is not fully understood. Moreover, too frequent an exposure to products containing nanosilver in sublethal amounts raises widespread concerns that it will lead to the development of silver-resistant microorganisms. Therefore, this study aimed to evaluate the mechanism of action of Ag-NPs on hMSCs by analyzing the cellular uptake of Ag-NPs by the cells and its effect on their viability and to assess antimicrobial activity of Ag-NPs against emerging bacterial strains, including multidrug-resistant pathogens. For metabolic activity and viability evaluation, hMSCs were incubated with different concentrations of Ag-NPs (14 µg/mL, 7 µg/mL, and 3.5 µg/mL) for 10 min., 1 h and 24 h and subsequently analyzed for their viability by live-dead staining and metabolic activity by the MTS assay. The effect of Ag-NPs on bacterial pathogens was studied by determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). In conclusion, it was observed that exposure of hMSCs to Ag-NPs of size <10 nm has no cytotoxic effect on the metabolic activity of the cells at the concentration of 3.5 µg/mL, with minimal cytotoxic effect being observed at the concentration of 14 µg/mL after 24 h of incubation. Our findings also confirmed that Ag-NPs at the concentration of 4 µg/mL are effective broad-spectrum bactericidal agents, regardless of the antibiotic-resistance mechanism present in bacteria.

The Use of Collagen Matrix in the Treatment of Gingival Recession-A Pilot Study.

BACKGROUND: Gingival recessions are common mucogingival deformities and conditions around teeth, which are described as the apical migration of tissues in the relation to the cementoenamel junction. One of the types of graft materials used to treat these recessions is the collagen graft material. The aim of this pilot study was to evaluate the effectiveness of the use of the collagen matrix combined with the coronally advanced flap surgery method to cover dental recessions, after a 12 month follow-up period. METHODS: The following parameters were assessed in 20 patients, with 38 single or multiple Miller class I or II gingival recessions: depth of the recession-RD; width of the recession-RW; height of the keratinized tissue-HKT; and thickness of the keratinized gingivae-GT. The percentage of the root coverage after 12 months was also calculated. RESULTS: There was a significant difference in the RD and RW values before and after the procedure. On average, the RD decreased by 3.39 mm, and the RW by 3.87 mm. Moreover, the values of the GT and HKT, before and after the treatment, significantly increased by 0.98 mm and 1.13 mm, respectively. The partial root coverage was 43.48%, and the total root coverage was 56.52%. CONCLUSION: The use of the collagen matrix with a split thickness gingival flap to cover the gingival recessions is a predictable and effective method when the clinician carefully follows the recommendation of the producer, which was confirmed in a 1 year follow-up with good clinical results.

Immunoglobulin Disorders and the Oral Cavity: A Narrative Review.

The oral mucosa is a mechanical barrier against the penetration and colonization of microorganisms. Oral homeostasis is maintained by congenital and adaptive systems in conjunction with normal oral flora and an intact oral mucosa. Components contributing to the defense of the oral cavity include the salivary glands, innate antimicrobial proteins of saliva, plasma proteins, circulating white blood cells, keratinocyte products of the oral mucosa, and gingival crevicular fluid. General disturbances in the level of immunoglobulins in the human body may be manifested as pathological lesions in the oral mucosa. Symptoms of immunoglobulin-related general diseases such as mucous membrane pemphigoid (MMP), pemphigus vulgaris (PV), linear IgA bullous dermatosis (LABD), Epidermolysis Bullosa Aquisita (EBA), and Hyper-IgE syndrome (HIES) may appear in the oral cavity. In this review, authors present selected diseases associated with immunoglobulins in which the lesions appear in the oral cavity. Early detection and treatment of autoimmune diseases, sometimes showing a severe evolution (e.g., PV), allow the control of their dissemination and involvement of skin or other body organs. Immunoglobulin disorders with oral manifestations are not common, but knowledge, differentiation and diagnosis are essential for proper treatment.

Oral Hygiene Considerations in Adult Patients with Leukemia during a Cycle of Chemotherapy.

The oral cavity is the place where the first symptoms of systemic diseases may appear. Leukemia is the malignancy of the hematopoietic system in which abnormal leukocytes are produced in the bone marrow and these cells spread to the peripheral blood. It is classified clinically on the basis of the duration and nature of the disease (acute or chronic), the type of cell involved (myeloid, lymphoid, or monocytes), and a rise in the number of abnormal cells in the blood. The study aimed to assess and compare the oral hygiene and periodontium status based on the indices in leukemic patients before and after one cycle of chemotherapy and whether the therapy had an impact on the change of these parameters. Dental indices used in clinical diagnostics were calculated: API (approximal plaque index), SBI (sulcus bleeding index), and CPI (community periodontal index). The research project was conducted at the Clinic of Hematooncology and Bone Marrow Transplantation of the Independent Public Clinical Hospital No. 1 in Lublin. The target population consisted of 102 adults with leukemia who were over 18 years of age. The time since diagnosis of the disease ranged from 1 to 10 years. The data were evaluated in the Statistica 12 software with the respective tests. In the majority of patients, both before and after chemotherapy, improper oral hygiene and severe generalized periodontitis were confirmed. The cycle of chemotherapy that was used did not correlate with the change of patients' oral hygiene and periodontium state. Unsatisfactory oral hygiene and periodontal health has to be addressed with urgent dental treatment to avoid systemic complications in leukemic patients.

Armed to the Teeth-The Oral Mucosa Immunity System and Microbiota.

The oral cavity is inhabited by a wide spectrum of microbial species, and their colonization is mostly based on commensalism. These microbes are part of the normal oral flora, but there are also opportunistic species that can cause oral and systemic diseases. Although there is a strong exposure to various microorganisms, the oral mucosa reduces the colonization of microorganisms with high rotation and secretion of various types of cytokines and antimicrobial proteins such as defensins. In some circumstances, the imbalance between normal oral flora and pathogenic flora may lead to a change in the ratio of commensalism to parasitism. Healthy oral mucosa has many important functions. Thanks to its integrity, it is impermeable to most microorganisms and constitutes a mechanical barrier against their penetration into tissues. Our study aims to present the role and composition of the oral cavity microbiota as well as defense mechanisms within the oral mucosa which allow for maintaining a balance between such numerous species of microorganisms. We highlight the specific aspects of the oral mucosa protecting barrier and discuss up-to-date information on the immune cell system that ensures microbiota balance. This study presents the latest data on specific tissue stimuli in the regulation of the immune system with particular emphasis on the resistance of the gingival barrier. Despite advances in understanding the mechanisms regulating the balance on the microorganism/host axis, more research is still needed on how the combination of these diverse signals is involved in the regulation of immunity at the oral mucosa barrier.

Studies of Peculiar Mg-Containing and Oscillating Bioapatites in Sheep and Horse Teeth.

New types of biological apatites have been discovered in molar sheep and horse teeth and are divided in two types. In the first and more general type, the release of Mg ions is parallel to the changes in composition of apatite leading to a final stoichiometric ratio of Ca to P ions, going from dentin depth towards the boundary of enamel with air. Inside dentin, another apatite sub-types were discovered with alternating layers of Mg-rich and C-rich apatites. The approximate formal stoichiometric relationships for these peculiar types of bioapatites are suggested. We identified two kinds of ion-exchanges responsible for formation of peculiar apatites. Various combinations of main and minor elements lead to new versions of biological apatites.

Changes of Dentition State in Leukemic Patients during Chemotherapy.

A number of systemic diseases including hematological disorders have manifestations in the oral cavity region. These manifestations may often represent early signs of the underlying hematopoietic disease and occur frequently in leukemia. Despite the fact that leukemia has long been known to be associated with oral health deterioration, the available literature on this topic consists mostly of case reports, without data to conclude these. The aim of the study was to assess dentition state in leukemic patients during one cycle of chemotherapy and its correlation with blood parameters. The study included 102 adults treated because of leukemia at the Clinic of Haemato-Oncology and Bone Marrow Transplantation at the university hospital in Lublin, Poland. The sample group consisted of 51 women and 51 men aged 22 to 72 (54.07 ± 10.33) with following diagnoses: Acute myelogenous leukemia (AML)-55 patients (53.92%), Chronic lymphocytic leukemia (CLL)-17 patients (16.67%), Acute lymphoblastic leukemia (ALL)-16 patients (15.69%), Chronic myelogenous leukemia (CML)-10 patients (9.80%), Acute promyelocytic leukemia (APL) -3 patients (2.94%), Chronic hairy cell leukemia (HCL)-1 patient (0.98%). DMFT index was used to assess dentition state. After the cycle of chemotherapy, their dentition state changed in terms of decayed, missing and filled teeth and correlated with hematological parameters. Adult patients with leukemia have high dental treatment needs, and high number of missing teeth; thus, a comprehensive and fast dental treatment is necessary to avoid systemic complications and ensure better quality of life.

The state of the oral health in patients with type 2 diabetes.

Over 3 mln people in Poland suffer from diabetes out of which 1/3 are undiagnosed. Diabetes is a metabolic disease characterized by the chronic hyperglycaemia resulting from disturbances in insulin secretion and tissue resistance to its action. The most serious clinical problem in the diabetics is periodontal disease since hyperglycaemia influences the disturbance of the immune response and increases the number of periopathogens. AIM: The aim of the study was an assessment of the oral health in patients with type 2 diabetes. MATERIALS AND METHODS: The study was conducted in the group of 450 people who reported to the selected specialist medical centers at the Rural Medicine Institute. Adult patients from Lublin macroregion were referred to the Department. 153 people among the studied were Diabetic Clinic patients with type 2 diabetes The assessment of the oral health was carried out on the basis of clinical examination included DMFt - the number of teeth with decay (D), the number of teeth removed because of tooth decay (M) or filled (F), index and masticatory function loss index (t). The results are summarized in tables and subjected to statistical analysis. A non- parametric Kruskall-Wallis test was used. RESULTS: In the group up to 34 years of age the number of extracted teeth was higher in healthy people. The index of masticatory function loss below 100% was higher in the diabetic patients. CONCLUSIONS: Diabetic outpatient clinic patients should receive special dental care and frequent check-ups.