[Mechanism and risk factors of oral biofilm formation]

A Novel Coating of Orthodontic Archwires with Chlorhexidine Hexametaphosphate Nanoparticles

Statement of the Problem. The use of orthodontic fixed appliances may adversely affect oral health leading to demineralizing lesions and the development of gingival problems. Aims of the Study. The study aimed to coat orthodontic archwires with chlorhexidine hexametaphosphate nanoparticles (CHX-HMP NPs) and to evaluate the elusion of CHX from CHX-HMP NPs. Materials and Methods. A solution of CHX-HMP nanoparticles with an overall concentration of 5 mM for both CHX and HMP was prepared, characterized (using atomic force microscope and Fourier transformation infrared spectroscopy), and used to coat orthodontic stainless steel (SSW) and NiTi archwires (NiTiW). The coated segments were characterized (using scanning electron microscopy SEM with energy dispersive X-ray spectrometry and field emission SEM) and subjected to the elusion assessment. Results. After having their composition validated, the average size of the CHX-HMP NPs was assessed to be 51.21 nm, and the analysis revealed that the particles had both chlorine and phosphorus. After 30 minutes in the coating solution, NPs deposited on the surface of the SSW and NiTiW. A continuous release of soluble CHX in artificial saliva was detected from both SSW and NiTiW as long as the experiment lasted for 28 days without reaching a plateau. However, the release from coated NiTiW was significantly more than coated SSW at 7, 14, and 28 days. While at day 21, the release from coated SSW was slightly greater than that from the coated NiTiW. Conclusion. Orthodontic stainless steel and NiTi archwires can be successfully coated with CHX-HMP NPs and give sustained release of CHX along the examined period.

Bee Venom, Honey, and Royal Jelly in the Treatment of Bacterial Infections of the Oral Cavity: A Review

Oral diseases affect a very large number of people, and the applied pharmacological methods of treatment and/or prevention have serious side effects. Therefore, it is necessary to search for new, safer methods of treatment. Natural bee products, such as honey, royal jelly, and bee venom, can be a promising alternative in the treatment of oral cavity bacterial infections. Thus, we performed an extensive literature search to find and summarize all articles about the antibacterial activity of honey, royal jelly, and bee venom. Our analysis showed that these bee products have strong activity against the bacterial strains causing caries, periodontitis, gingivitis, pharyngitis, recurrent aphthous ulcers, supragingival, and subgingival plaque. An analysis of average MIC values showed that honey and royal jelly have the highest antimicrobial activity against Porphyromonas gingivalis and Fusobacterium nucleatum. In turn, bee venom has an antibacterial effect against Streptococcus mutans. Streptococcus sobrinus and Streptoccus pyogenes were the most resistant species to different types of honey, and royal jelly, respectively. Moreover, these products are safer in comparison to the chemical compounds used in the treatment of oral cavity bacterial infections. Since the antimicrobial activity of bee products depends on their chemical composition, more research is needed to standardize the composition of these compounds before they could be used in the treatment of oral cavity bacterial infections.

Improvement of Properties of Stainless Steel Orthodontic Archwire Using TiO2:Ag Coating

Orthodontic treatment carries the risk of major complications such as enamel demineralization, tooth decay, gingivitis, and periodontal damage. A large number of elements of fixed orthodontic appliance results in the creation of additional plaque retention sites which increase the risk of biofilm creation. Modification of the surface of orthodontic elements may prevent the formation of bacterial biofilm. In this paper, surface modification of stainless steel orthodontic wires with TiO2: Ag was carried out by the sol-gel thin film dip-coating method. To obtain the anatase crystal structure, substrates were calcined for 2 h at 500 °C. The properties of the obtained coatings were investigated using scanning electron microscopy, X-ray diffraction, and electrochemical tests. Corrosion studies were performed in a Ringer’s solution, which simulated physiological solution. SEM and XRD analyses of the coated surface confirmed the presence of Ag nanoparticles which may have antimicrobial potential.

Oral Biofilm: Development Mechanism, Multidrug Resistance, and Their Effective Management with Novel Techniques

Biofilms are formed by the congregation of one or more types of microorganisms that can grow on a firm surface. Dental plaque is one of the most commonly forming biofilms in the oral cavity and appears as a slimy layer on the surface of the teeth. In general, the formation is slow, but biofilms are very adaptive to the changing environment, and a mature biofilm can cause many health-related problems in humans. These biofilms remain unaffected by antibiotics as they do not allow the penetration of antibiotics. Moreover, the increased level of virulence and antibiotic resistance of microorganisms in the oral biofilm or dental plaque has made its clinical management a serious challenge worldwide. Chlorhexidine-like antimicrobial drugs have been partially effective in removing such organisms; however, the precise and continuous elimination of these microorganisms without disturbing the normal microbial flora of the oral cavity is still a challenge. This review paper focuses on the process of oral biofilm formation, related complications, development of drug-resistant bacteria in these biofilms, and their effective management by the use of different novel techniques, available from various published research and review articles.

Functional Coatings for Orthodontic Archwires-A Review

In this literature review, the current state-of-art of coatings for orthodontic archwires’ increasing antimicrobial and relevant mechanical properties, such as surface topography, friction or corrosion resistance, has been presented. There is a growing request for orthodontic appliances, therefore, most researchers focus on innovative functional coatings to cover orthodontic archwires and brackets. Orthodontic appliances are exposed to the unfavorable oral cavity environment, consisting of saliva flow, food, temperature and appliance force. As a consequence, friction or biocorrosion processes may occur. This can affect the functionality of the orthodontic elements, causing changes in their microstructure, surface topography and mechanical properties. Furthermore, the material which the orthodontic archwire is made from is of particular importance in terms of the possible corrosion resistance. This is especially important for patients who are hypersensitive to metals, for example, nickel, which causes allergic reactions. In the literature, there are some studies, carried out in vitro and in vivo, mostly examining the antibacterial, antiadherent, mechanical and roughness properties of functional coatings. They are clinically acceptable but still some properties have to be studied and be developed for better results. In this paper the influence of additives such as nanoparticles of silver and nitrogen-doped TiO₂ applied on orthodontic brackets by different methods on the antimicrobial properties was analyzed. Future improvement of coating techniques as well as modification of the archwire composition can reduce the release of nickel ions and eliminate friction and bacterial adhesion problems, thus accelerating treatment time.

Аnalysis of the exposure of the medical-preventive toothpaste containing bicarbonate and sodium fluoride on the status of oral cavity in inflammatory diseases of fabric of parоdontium in young patients (clinical and laboratory research)

Relevance of the research topic. Evaluation of changes in the index characteristics of oral hygiene, physicochemical parameters of mixed saliva (pH, buffer capacity of saliva, redox potential, osmolality and others) allows to determine the quality of the effect of toothpaste «Рarodontax ultra clean» on the state of the oral cavity. The use of mixed saliva as a biological fluid of the body as an object of study is confrmed by its high information content and availability of diagnostic material. Studies of changes in mixed saliva, whose components affect the composition, accumulation of microbial plaque and the process of its calcifcation are appropriate.

Purpose. То evaluate the clinical effcacy of toothpaste «Рarodontax ultra clean», the complex effect of its components on the tissues of the teeth and of fabric of parоdontium, to determine the possible mechanism of anti-inflammatory action.

Materials and methods. The experiment involved 58 people. The clinical examination included: Green-Vermillion hygiene indices; bleeding, gingivitis, parоdontium indices. Laboratory studies of unstimulated mixed saliva included parameters: qualitative analysis of the secret, a number of physico-chemical parameters; crystallographic characteristics. For an integrated assessment of nonspecific resistance of the oral cavity, the reaction of adsorption of microorganisms by epithelial cells was used.

Results. In the course of use by patients of toothpaste «Рarodontax ultra clean», an improvement in the oral hygiene condition was noted, a decrease in the rate of plaque formation was diagnosed in 100% of cases, which is clinically confrmed by positive dynamics of hygiene indices (p < 0.05). With regular use of toothpaste, the inflammation of the gums decreases: after 7 days the bleeding of the gums decreases twice, after 14 days - 4.5 times. Summary. The use of toothpaste «Рarodontax ultra clean» leads to a qualitative transformation of the structure of mixed saliva in patients: an improvement in microcrystallization, an increase in salivation, an increase in pH values and bringing it into the range of normal values, an increase in buffer capacity and osmolality. Ingredients such as sodium bicarbonate, silicon dioxide and sodium fluoride contribute to the improvement of metabolic processes in the oral cavity and the adsorption properties of the epithelium after exposure to the investigated toothpaste.

The role of Tannerella forsythia and Porphyromonas gingivalis in pathogenesis of esophageal cancer

Tannerella forsythia and Porphyromonas gingivalis are anaerobic, Gram-negative bacterial species which have been implicated in periodontal diseases as a part of red complex of periodontal pathogens. Esophageal cancer is the eight most common cause of cancer deaths worldwide. Higher rates of esophageal cancer cases may be attributed to lifestyle factors such as: diet, obesity, alcohol and tobacco use. Moreover, the presence of oral P. gingivalis and T. forsythia has been found to be associated with an increased risk of esophageal cancer. Our review describes the role of P. gingivalis and T. forsythia in signaling pathways responsible for cancer development. It has been shown that T. forsythia may induce pro-inflammatory cytokines such as IL-1β and IL-6 by CD4 + T helper cells and TNF-α. Moreover, gingipain K produced by P. gingivalis, affects hosts immune system by degradation of immunoglobulins and complement system (C3 and C5 components). Discussed bacteria are responsible for overexpression of MMP-2, MMP-2 and GLUT transporters.

CLINICAL AND LABORATORY SUBSTANTIATION OF APPLICATION OF TREATMENT-AND-PROPHYLACTIC GEL REDUCING TOOTHPASTE WITH SODIUM FLUORIDE IN YOUNG PATIENTS

Object. The paper analyzes the change in the physical and chemical properties of mixed saliva in patients with the course of use of toothpaste "Sensodyne® Recovery and protection" containing NovaMin and sodium fluoride. The analysis of the survey of organoleptic properties of toothpaste, clinical examination of patients with hyperesthesia and laboratory parameters of mixed saliva in dynamics was carried out. Purpose. Rationale for the use of therapeutic and prophylactic toothpaste "Sensodyne® Recovery and protection" with sodium fluoride for sensitive teeth in young patients. Methodology. A clinical examination of the oral cavity of young patients (50 men, mean age of 22.50±2.59 years), index estimation of a condition of the teeth (CPUs, municipal production unitary enterprise), oral hygiene (J. R. Green, J. R. Vermillion, 1964), the determination of "teeth sensitivity" (method L. Y. Nut–Litovskogo S. B.); the study of mixed saliva (qualitative analysis, salumeria; concentration of fluorine ions and sodium, pH, redox potential, total zhestkost) exchange rate before and after application of toothpaste. Results. A pronounced clinical effect was obtained, which manifests itself in the cleansing qualities (p≤0.05), and in the elimination of hyperesthesia (p≤0.05) in all patients. The increase of pH values (p≤0.05) was revealed. After cleaning in the sample of mixed saliva, the concentration of fluoride ions increases by 22%, the content of sodium ions decreases by 35.4%, the content of calcium and magnesium ions decreases. This contributes to the formation of stable fluorapatite Ca5(PO4)3F in the surface layers of enamel. calcium ions from phosphosilicate calcium-sodium (NovaMin) go directly from the toothpaste "Sensodyne® repair and protect" with the sodium fluoride in the construction of the hydroxyapatite of tooth enamel. Summary. Thus, the analysis of the results of the survey evaluation of the organoleptic properties of toothpaste "Sensodyne® Recovery and protection" containing sodium fluoride, which are estimated to be highly valued, clinical examination of patients with hyperesthesia and laboratory parameters of mixed saliva in dynamics, showed a significant clinical effect: improving the cleaning ability of toothpaste, reducing the sensitivity of teeth in 100% of patients.

Antimicrobial activity of the chloroform fraction of Drynaria fortunei against oral pathogens

Drynaria fortunei (D. fortunei), widely used in traditional Korean medicine, is reportedly effective in treating inflammation, hyperlipidemia, bone fractures, oxidative damage, arteriosclerosis, rheumatism, and gynecological diseases. The objective of this study was to evaluate the antibacterial effects of the chloroform fraction of D. fortunei (DFCF) and assess the synergistic effects of DFCF with antibiotics against bacterial pathogens. This was carried out by calculating the minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) and performing checkerboard dilution test and time-kill assays. The MICs/MBCs for DFCF, ampicillin, and gentamicin against all oral strains were >39-2,500/5,000 μg/mL, 0.25-64/0.25-64 µg/mL, and 0.5-256/1-512 µg/mL, respectively. DFCF exhibited the highest activity against the periodontic pathogens Prevotella intermedia and Porphylomonas gingivalis. DFCF in combination with ampicillin showed a strong synergistic effect against oral bacteria (fractional inhibitory concentration (FIC) index ≤0.5), whereas on combining with gentamicin, it reduced the on half-eighth times than used alone (FICI ≤ 0.5). DFCF combined with ampicillin or gentamicin killed 100% of most tested bacteria within 3-4 h. The results of this study demonstrate the antimicrobial and synergistic activity of DFCF and antibiotics against oral pathogens.