[Distinctions in molecular composition of the dental biofilm depending on the method of exo-/endogeneous caries prevention and cariogenic condition of a patient]. / Osobennosti molekulyarnogo sostava zubnoi bioplenki v zavisimosti ot metoda ekzo-/endogennoi profilaktiki kariesa i kariesogennoi situatsii u patsienta.

PURPOSE OF THE STUDY: For the first time distinctions of molecular composition of the dental biofilm at the stages of exo- and endogeneous caries prevention were studied for persons with different cariogenic conditions involving synchrotron molecular spectroscopy techniques. MATERIAL AND METHODS: The samples of the dental biofilm collected from participants of the research were studied at the different stages of experiment. The studies of molecular composition of the biofilms were employed involving the equipment set in the Infrared Microspectroscopy (IRM) laboratory of Australian synchrotron. RESULTS: Basing on the data obtained by synchrotron infrared spectroscopy with Fourier transform as well as using the calculations of the ratios between organic and mineral components and also statistical analysis of the data we could estimate the changes proceeding in the molecular composition of dental biofilm in a dependence of homeostasis conditions in the oral cavity at the stages of exo- and endogeneous caries prevention. CONCLUSION: Observed changes in the values of phosphate/protein/lipid, phosphate/mineral and phospholipid/lipid ratios as well as the presence of statistically significant intra- and intergroup in these coefficients mean that mechanisms of adsorption for the ions, compounds and molecular complexes incoming from the oral fluid into the dental biofilm at the stage of exo-/endogeneous caries prevention are different for the patients in normal condition and for those ones with the developing caries.

[Biomimetic strategy of a hybrid biointerface creation between native human dental tissue and dental composite]. / Biomimeticheskaya strategiya v osnove sozdaniya gibridnogo biointerfeisa mezhdu nativnoi zubnoi tkan'yu cheloveka i stomatologicheskim kompozitom.

OBJECTIVE: The aim of the studyis the peculiarities of the molecular composition of the biointerface between the native human dental tissue and the dental composite, created in an alkaline environment, based on synchrotron chemical infrared micro-mapping. MATERIAL AND METHODS: When creating a biomimetic interface under alkaline conditions, we used an original bioprimer, dentin conditioner, nanofilled universal adhesive, and a light-curing compomer based on BIS-GMA. RESULTS: Biointerface analysis was carried out on the basis of chemical infrared micro-mapping, implemented using the equipment of the Australian Synchrotron, and subsequent multivariate cluster analysis of the collected spectral data array. It was shown that the use of a primer modified with a set of polar amino acids additionally facilitated the opening of dentinal tubules and the penetration of the bioprimer components into the dentin with the formation of a deeper transitional hybrid layer. At the same time, modification of the Bis-GMA adhesive using nanocrystalline carbonate-substituted hydroxyapatite, which has a structural and morphological organization similar to natural dental tissue apatite, led to an increase in the degree of conversion of the used adhesive material during polymerization. CONCLUSION: Using a biomimetic strategy and nanocrystals of carbonate-substituted hydroxyapatite as a filler of a universal adhesive, the necessary conjugation at the interface with dentin can be achieved without disrupting the polymerization processes, as well as preserving the natural structural complexity of the intact tissue, which makes it possible to take into account the individual characteristics of the patient.

[Spectroscopic studies of the molecular composition of the dentinal and gingival fluids and their diagnostic potential for preventive screening of dentin caries]. / Spektroskopicheskie issledovaniya molekulyarnogo sostava dentinnoi i desnevoi zhidkostei i ikh diagnosticheskii potentsial dlya preventivnogo skrininga kariesa dentina.

PURPOSE OF THE STUDY: The aim of the work is a spectroscopic investigation and comparison of the molecular composition of dentine and gingival fluids as well as of their diagnostic potential for the preventive screening of dentin caries. MATERIAL AND METHODS: Applying infrared spectroscopy including synchrotron radiation the samples of biological fluids taken from the oral cavity (dentine fluid, fluid from the gingival sulcus and blood) were studied for the patients with the progressive dentine caries. The part of this research was undertaken with the infrared microspectroscopy beamline at the Australian Synchrotron. RESULTS: Dentine and gingival fluids were shown to have no less complicated composition than the blood serum. Having all this in mind, in spite that these two fluids are derivatives of the blood serum, and a majority of the molecular groups observed in all of the three fluids can be detected in their IR-spectra, it follows that there is a number of signature modes that are in fact present in the IR spectra of only dentine and gingival fluids. This fact indicates at the molecular exchange between them under certain conditions. It means the high diagnostic potential in the study of the pathologic processes occurring in the oral fluid of a human. We have observed and fixed an increase of thiocyanates and esters in the samples of both dentine and gingival fluids under the development of dentin caries. CONCLUSION: Utilization of the gingival fluid for screening taking into account that its sampling is not such a complicated challenge as dentine fluid sampling will promote a transition to the personalized medicine, the development of high-technology healthcare and technology of the health preservation as a whole.

Organic-Mineral Interaction between Biomimetic Materials and Hard Dental Tissues.

The aim of the investigation was to study the integration between native human dental tissue and new-generation biomimetic materials replicating the mineral-organic complex of dentin and enamel using IR microspectroscopy for multidimensional visualization and analysis. MATERIALS AND METHODS: The conditions for stable integration at the interface between biomimetic material and natural hard tissue were identified using a biocomposite buffer system of nanocrystalline carbonate-substituted calcium hydroxyapatite corresponding in its total characteristics to human dentin-enamel apatite and a number of amino acids present in the organic matrix of dentin and enamel: L-histidine, L-lysine hydrochloride, L-arginine hydrochloride, and hyaluronic acid. The finished samples were studied using IR microspectroscopy on IRM channel equipment (The Australian Synchrotron, Melbourne, Australia). RESULTS: The characteristic features of the biomimetic buffer layer at the interface between the enamel and dental material were revealed and visualized based on IR mapping of absorption intensity for particular functional molecular groups with the use of synchrotron radiation, location of the functional groups involved in the processes of biomimetic composite integration was identified.

[Spectroscopic studies of the changes occurring in the molecular composition of oral fluid in people with multiple caries]. / Spektroskopicheskie issledovaniia izmenenii v molekuliarnom sostave rotovoi zhidkosti u liudei s mnozhestvennym kariesom zubov.

The changes in molecular composition of mixed saliva (oral fluid) were analyzed with the use of spectroscopic techniques for the patients with multiple caries. Using Fourier-transform infrared spectroscopy studies including synchrotron radiation for the excitation certain features were detected in the IR-spectra of the oral fluid. Mineral-organic, carbon-phosphate, AmidII/AmidI and protein/thiocyanate ratios were calculated for the groups of patients with multiple caries and patients of the control group. Complex analysis of the obtained experimental data enabled to determine that in the oral fluid of the persons with multiple caries as compared with the control group content of the mineral groups and complexes is reduced while the share of organic component is increased. Content of thiocyanate increases by more than two times and there appear carboxyl groups of esters, lipids and carbohydrates. The detected features in IR-spectra of mixed saliva as well as the changes found in its molecular composition based on the calculated ratios between organic and inorganic components can be used as biomarkers of cariogenic condition in the oral cavity. It can be used as a diagnostic criterion in the analysis of the oral fluid samples taken from the patients.

[Increased oral fluid remineraling function by endogenous and exogenous saturation methods of its mineral complexes]. / Povyshenie remineraliziruiushchei funktsii rotovoi zhidkosti s pomoshch'iu éndogennykh i ékzogennykh metodov nasyshcheniia ee mineral'nymi kompleksami.

RELEVANCE: One of the most common problems in modern caries prevention is the development of techniques to increase tooth resistance to the effects of cariogenic factors. Therefore, research is needed to study the chemical composition of tissues like teeth and body fluids surrounding the tooth to prevent demineralization process. The purpose of determining the effectiveness of work- and correlation relationship between endo saturation exogenous methods oral liquid mineral complexes. MATERIAL AND METHODS: In 95 patients analyzed the chemical composition and structure of the oral fluid by IR spectroscopy. For the collection of IR spectra used Verteh-70 spectrometer ('Bruker', Germany) and the prefix of frustrated total internal reflection PLATINUM ATR diamond prism. RESULTS AND DISCUSSION: A correlation between the use of endogenous and exogenous methods of caries prevention, in favor of the former, as well as changes in the mineral-organic and phosphate-carbon ratio in the dry residues of oral fluid.

[Investigation of mechanisms of interaction between inulinase from Kluyveromyces marxianus and the matrices of ion-exchange resins and fiber].

It is established that ion exchange resins AV-17-2P, KU-2, AV-16-GS, AM 21A, IMAC-HP, PUROLITE and fiber VION KN-1 can be applied as carriers for inulinase immobilization. The analysis of IR spectra for an enzyme, carriers and heterogeneous enzyme preparations showed that inulinase binding to matrices of various carriers occurs in general through electrostatic interactions. It is assumed that the mechanisms of interaction between inulinase from Kluyveromyces marxianus and the matrices of cation- and anion exchange polymers differ essentially from each other: different sites of protein molecule take part in adsorption that causes various conformational reorganizations in an enzyme molecule.