COMPARATIVE STUDY OF FLEXURAL STRENGTH OF PHOTOCOMPOSITE DENTAL ENAMEL SEALANTS

Background. Dental caries is a widespread worldwide disease of multifactorial genesis. The leading mechanism of its development is a long-term imbalance of the physiological balance between the inorganic component of the teeth hard tissues and the liquid biofilm formed on their surface, the predominance of the demineralization processes in hard tissues over the processes of remineralization. The use of dental enamel sealants has proven to be effective in preventing and reducing the intensity of dental caries. Modern bioactive polymer sealants for enamel contain such remineralizing agents as sodium fluoride, nanoamorphous calcium phosphate, beta-tricalcium phosphate, and particles of bioactive glass. For all dental composite filling materials, mechanical stability is one of the prerequisites for the long-term clinical success of restorations and fillings, and accordingly, temporary protective structures made of sealants. Aim: to compare the flexural strength and modulus of elasticity of three modern photocomposite enamel sealants. Materials and methods. In laboratory conditions for three modern photocomposite dental materials for sealing fissures and pits of enamel "Fissurit FX" (VOCO), "Clinpro™ Sealant" (3M™ ESPE™) and "Jen-Fissufil" (Jendental-Ukraine LLC) a flexural strength (three-point test) and elastic modulus were determined in accordance with the requirements of the international standard ISO 4049:2019. 6 samples of each material, polymerized and kept for a day in humid conditions, were examined. Results. The highest elastic modulus and flexural strength were in "Fissurit FX" – 5.17±0.80 GPa (M=5.00 GPa) and 130.07±7.75 MPa (M=127.81 MPa), respectively. In "Clinpro™ Sealant" the elastic modulus was 2.97±0.12 GPa (М=3.00 GPa), the flexural strength was 100.01±14.33 (М=96.73) MPa. In "Jen-Fissufil" the elastic modulus was 3.47±0.52 GPa (M=3.17 GPa), the flexural strength was 90.91±6.66 MPa (M=93.02 MPa). The studied indicators of all three materials exceeded the requirements of the international standard ISO 4049:2019. Conclusion. The performed studies showed high mechanical properties of all three dental sealants for enamel and that they have the potential to withstand long-term periodic masticatory load when functioning on the surface of teeth

THE ROLE OF PLASMA ENRICHED WITH PLATELETS AND GROWTH FACTORS IN MODERN MEDICAL PRACTICE

The process of wound healing is often observed in injurys that occur in the body, can often vary between a clinic and manifestations, because today it remains questionable as to solve this problem. Modern medicine requires new treatments for this type of injury. One of them is the technology of plasma-rich platelets and growth factors. This type of biological treatment leads to natural tissue regeneration method by which you can optimize and reduce healing time. This is achieved through an array of proteins from plasma enriched with platelets, which are involved in the recovery of damaged tissues. Thus, their restoration is natural and involves removing dead cells, their proliferation and migration to the site of injury, where the formation of new vascular structures. The organization of these elements affects the healing process after damage, preventing loss of fibrous elements that cause the reduction of functional ability and reducing on the "volume of tissue. Growth factors play an important role in coordinating all processes of healing. This article reflects the relevant aspects of the application in medicine modern biological technology autoplazmy enriched with platelets. in recent years, marked a significant increase in interest for this biomaterial that caused high efficiency at a high level of safety and low cost. Nowadays, plasma rich in platelets actively used in surgery, dentistry, traumatology, orthopedics, cosmetic, etc. Autoaplazma enriched with platelets has several positive features, namely, speed up the regeneration of tissues, no anti-inflammatory effect, reducing pain. Growth factor is a naturally occurring substance capable of stimulating cellular growth, proliferation, healing, and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes. Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells. They often promote cell differentiation and maturation, which varies between growth factors. For example, bone morphogenetic proteins stimulate bone cell differentiation, while fibroblast growth factors and vascular endothelial growth factors stimulate blood vessel differentiation (angiogenesis). PRGFEndoret contains a cocktail of autologous growth factors that proceed from both the plasma and the platelets. In fact, the platelets have a complex storage system in the form of intracellular granules that allow them to transport a large number of biologically active molecules. According to some authors, this list of proteins and peptides can come close to 500 molecules. Alpha (α) granules are the most abundant as there are around 40 to 80 alpha granules per platelet, but they are also the ones with the greatest retention capacity. In addition, they contain a series of antibacterial proteins that are generically called thrombocidines and which are lethal for a large variety of bacterial species. The system of PRGF stands for Plasma Rich in Growth Factor. It is a technology developed to promote the regeneration, repair and healing of the injured and damaged tissues. In the article below, we have elaborated the methods of PRGF-Endoret application to patients suffering from injuries or damages to soft tissue in the maxillofacial area

Issues of therapy for biliary pathology in children: the choice of the optimal solution

Background. Diseases of the hepatobiliary system are one of the most important problems of pediatric gastroentero­logy. Lesions of the biliary tract are associated with persistent changes in lipid metabolism that contributes to the prolonged cholestasis and to the progression of the biliary pathology. The purpose of this study was to evaluate the efficacy and safety of Ursofalk® in the comprehensive therapy of biliary tract diseases and comorbid pathology in children. Materials and methods. The results of examination and integrated treatment of 55 children aged 5 to 18 years (31 girls and 24 boys) with diseases of the biliary tract and comorbid pathology were analyzed. The criteria for inclusion of patients in the study were: the pre­sence of diseases of the biliary tract accompanied by biliary sludge and blood lipid disorders. Diagnostic complex included: analysis of clinical data, ultrasound examination of abdominal organs, biochemical blood analysis (liver tests, lipid disorders). Depending on the comorbid pathology, all children received comprehensive treatment within a month. Patients were divided into two groups depending on choleretic therapy: group 1 (main) received conventional cholagogues, group 2 (comparison) — Ursofalk®. Licensed software products (Statistica, Excel) were used for statistical processing of the obtained data. Results. By the end of the treatment with Ursofalk® we observed positive dynamics in patients’ condition and laboratory indicators. In patients who received Ursofalk®, the manifestations of pain syndrome and dyspepsia completely disappeared. Children from the comparison group still had pain syndrome, a feeling of heaviness in the right upper quadrant and dyspepsia. The use of Ursofalk® normalized the parameters of the bile structure and the biochemical parameters of lipid metabolism. We registered a significant (p < 0.05) decrease in the incidence of impaired bile homogeneity — by 65.5 % in children from the main group. In children of the comparison group, it decreased only by 27.3 %. Positive dynamics of biochemical parameters was observed in both groups of patients, but with significant changes (p < 0.05) in the group of children taking Ursofalk®. Conclusions. Ursodeoxycholic acid (UDCA) use is pathogenetic justified for the correction of functional and metabolic disorders in biliary and comorbid pathologies in children. Ursofalk® administration in the comprehensive therapy of the diseases of the biliary system in children led to the rapid regression and relief of clinical symptoms and the improvement of laboratory-instrumental indicators. Ursofalk® is a reference product of UDCA. Availability of the officinal form of Ursofalk® in a special form for children (suspension) allows UDCA to be used in childhood, starting from the first days of life

Morphological studies in the diagnosis of primary and secondary bone tumors

The aim: to show the possibility of morphological studies in the diagnosis of primary and secondary tumors of bones. Material and Methods. 105 (72%) patients with primary bone tumors aged from 15 to 66 years and 42 (28%) patients with metastatic bone lesions aged from 42 to 70 years were examined and treated for the period from 2008 till 2015. Material for morphological studies was prepared using an open biopsy tissue slices and a scraping resected tumor during surgery. Soft-tissue component is subjected to cytology. The material for histological study included changes in bone and soft tissue. Results. Giant cell tumor was verified in 45% of cases by histological examination. Multiple myeloma was diagnosed in 15% of patients. Osteogenic sarcoma was diagnosed in 14% of cases. Ewing's sarcoma was diagnosed in 3%, 2% of cases were matched by diagnosed chordoma. According to the data received, cancer metastasis of kidney and lung is mostly diagnosed in men from the group of patients with secondary bone defeat. Metastasis of cancer of the breast in women was predominated. Conclusion. The morphological (histological, cytological) study plays an important role in the diagnosis of bone tumors. The coincidence of the cytological and histological diagnoses was 97%.</p

EXPERIMENTAL STUDY OF THE SAFETY OF INDIRECT CERAMIC RESTORATIONS REMOVAL BY COMPARING THE DYNAMICS OF THERMOMETRIC INDICATORS

Abstract. Today, porcelain laminate veneers are mainly used to optimize tooth form and position, close diastema, replace discoloured or unaesthetic composite resin restorations, restore teeth with incisal abrasions or tooth erosion, and mask or reduce tooth discoloration. They are a valid alternative to complete-coverage restorations since they avoid aggressive dental preparation, thus maintaining tooth structure. However, even such high-precision restorations have a failure rate and complications. Veneer removal is generally performed with a rotary instrument. Using this method, the veneer removal is complete, but is relatively time consuming and this technique is not ideal as the underlying tooth structure may be damaged. Moreover, the irritating noise, uncomfortable vibration and pain during veneer removal with high-speed handpieces are unpleasant for the patients. These disadvantages led to the search for new techniques for hard dental tissue removal, such as lasers, which would make treatment less painful to patients, with no need of local anaesthetics. With the recent introduction of lasers in dentistry, there may be beneficial application of lasers in removing veneers with lasers. Using an Er:YAG laser allows debonding porcelain veneers from teeth without aggressive destruction or removal of underlying tooth structure and without destroying the veneers. Purpose. The aim of our experimental study was to investigate the safety of indirect ceramic restorations removal by comparing the dynamics of thermometric indicators. Materials and methods. Experimental studies conducted at Shupyk National Medical Academy of Postgraduate Education. According to our study following groups were created: group 1 (control) – veneer removal using rotary instruments (24 veneers): IА–ceramic veneers, fabricated from VITABLOCS MarkII, IB – ceramic veneers, fabricated from IPS e.max CAD; group II – veneer removal using a solid-state laser (Er: YAG) (32 veneers): IIА – ceramic veneers, fabricated from VITABLOCS MarkII, IIB - ceramic veneers, fabricated from IPS e.max CAD; group III – veneer removal using a solid-state laser (Er, Cr: YSGG) (34 veneers): IIIА – ceramic veneers, fabricated from VITABLOCS MarkII, IIIB – ceramic veneers, fabricated from IPS e.max CAD. The intrapulpal temperature measurements were performed with thermocouple. Results of the study: According to the results of our study using an Er:YAG and Er, Cr: YSGG lasers allows debonding porcelain veneers from teeth without aggressive destruction or removal of underlying tooth structure and in most cases without destroying the veneers, make veneer debonding less painful to patients. Both laser groups generated significantly less heat compared to bur group (p<0,05). None of the laser groups increased pulpul axial wall heat temperature above the critical 5,5˚С (3,4˚С for Er:YAG and 2,3 for Er,Cr:YSGG lasers). The bur group generated higher heat (more than 5,5˚С). According to the results of our experimental study on thermal safety Er:YAG and Er, Cr:YSGG lasers allow to remove indirect ceramic restorations (veneers) below the critical threshold described of 5,5˚С (Zach and Cohen)