The purpose of this systematic literature analysis is to review the application features of various types of acids and to determine the most effective etching technique to achieve maximum elimination of the smear layer. Materials and methods: the analysis of up-to-date Russian and English literature was carried out in Google Scholar and PubMed electronic databases. The analysis identified the features of various etching techniques using phosphoric, maleic and polyacrylic acids to achieve maximum elimination of the smear layer. Results: during the analysis, 67 articles were examined. After analyzing the literature on the inclusion criteria, the total number of publications amounted 31. Conclusion: smear layer should be removed using phosphoric or maleic acids according types of tissues: phosphoric acid application used on the enamel, maleic acid is applied on the dentine due to ensure a high-quality adhesive protocol, taking into account the sparing effect on the structural and functional units of tissues. Recommended exposure: applied to the enamel for 15-30 seconds, taking into consideration the type and the molecular weight of the acid. The exposure time of acid on dentin is recommended from 10-15 seconds, but an increase in the exposure time of maleic acid on dentin did not lead to negative changes in the structure of dentin, which significantly distinguishes the use of orthophosphoric acid. Also, static batching is not enough for high-quality treatment, because, in case of static etching, only the internal areas consisting of enamel prisms can be fully etched. Consequently, the use of dynamic etching is recommended. All authors contributed equally to the writing of the article.

Deep margin elevation (DME) is a nonsurgical, alternative technique of dental crown lengthening. Portion of direct restoration placed only at the deep apical part of the cavity to elevate the margin to a more coronal and more adequate position for final cementation of indirect restoration.Materials and methods. In this systematic review, we were looking for in vitro studies in which deep margin elevation (DME) technique were used. The electronic databases PubMed and EMBASE were used for the search. The search began on July 29, 2021 and ended on August 10, 2021. We have analyzed the materials and methods of each research and entered them in the appropriate tables to give a clearer assessment of the obtained results.Results. Analysis of marginal quality showed the best results when indirect restorations luted to dentin directly and with DME technique with three consecutive layers of resin composite. In groups without DME there were fewer microleakage. DME did not statistically significantly influence the fracture strength.Conclusions. We conducted a systematic review that included 12 in vitro studies. Even though samples without DME showed better results in in vitro studies, the difference between samples with and without DME was not statistically significant. However, in clinical practice, DME facilitates the insertion of indirect restorations. Therefore, further studies and clinical observations are necessary.

This study aimed to investigate the effect of final sintering on the thermal properties and phase composition of yttrium-stabilized zirconium dioxide. Totally 15 yttrium-stabilized zirconium oxide standard ovoid samples were studied (3Y-TZP, IPS e.max ZirCAD LT, Ivoclar Vivadent, Schaan, Liechtenstein). This material contains the following components: ZrO2 - 87.0 - 95.0%, Y2O3 - 4.0 - 6.0%, HfO2 - 1.0 - 5.0%, Al2O3 - 0.0 - 1, 0%. Initially, X-ray diffraction analysis was performed. After that, differential scanning calorimetry was carried out up to a temperature of 900°C. X-ray diffraction analysis was performed to assess the effect of the firing process on the phase analysis of zirconia samples (Selected samples were tested on an X-ray diffraction instrument (EMPYREAN, PANalytical, Lelyweg, The Netherlands) The thermal changes study in zirconia samples resulting from repetitive firing processes was performed then. Samples were placed in a differential scanning calorimeter (NETZSCH STA 409 PC Luxx, Bavaria, Germany) and heated at a rate of 10°C/min from 50°C to 900°C.) Then, differential scanning calorimetry data (the mass and structural changes of zirconia samples depending on temperature) was recorded. The percentage of the monoclinic phase increases on average from 3.6% to 7.5%, but this difference is not statistically significant (p=0.1). Two exothermic peaks were observed when the samples were heated from 50°C to 900°C. The final firing of 3Y-TZP zirconium crown up to 900°C slightly increases the content of the monoclinic phase and causes exothermal changes.

Vital pulp therapy is a biologic and conservative treatment to preserve the vitality and function of the pulp tissue. Indirect pulp capping is one of the techniques which can be done with Ca(OH)2. The success rate of using Ca(OH)2 during treatment of reversible pulpitis isn’t so high. And the reactivity of the vital pulp is reduced when exposed to an aggressive calcium hydroxide-based material. According to the international classification of diseases, reversible pulpitis is considered as K04.00 – initial pulpitis. The purpose of this review article is to assess systematically the available scientific evidence about the clinical response of pulp-dentin complex after using Ca(OH)2 for indirect pulp capping. Materials and methods: The study of publications was produced in the electronic databases such as Google Scholar, PubMed during a systematic review of the literature. Included articles contain information about using Ca(OH)2 during treatment of initial pulpitis and its side effects. The publication date criterion was selected from January 2011 to July 2021. Results: 55 articles were viewed during the review. After analyzing the literature for inclusion criteria, the total number of publications has become 10. Conclusions: According to literature data, the using calcium hydroxide for indirect pulp capping during treatment of the reversible (initial) pulpitis is decreasing due to the side effects and clinical response from dentin pulp complex.

Aim. To study the prevalence, intensity and features of the clinical course of caries in children from 1 to 5 years old, to improve the registration of dental morbidity.Materials and methods. An epidemiological and clinical examination of the child population was carried out as part of preventive medical examinations of minors. The study involved 1930 children from Moscow, aged from 1 to 5 years. The epidemiological survey was carried out to study the dental morbidity in children of early childhood and preschool age. Clinical research methods were carried out to determine the dental status of the subjects. All studies in children were performed with informed voluntary consent. Parents or legal representatives signed their consent to the survey. Results. Analysis of the results of preventive medical examinations of minors made it possible to determine the prevalence, intensity and characteristics of the clinical course of caries in the period of early childhood (preschool period) and preschool age among the children's population of Moscow.Conclusions. It was found that the prevalence and intensity indicators increase as children grow up, the depth of the lesion and the localization of carious lesions change at different age periods.