H. M. Nalchajyan

A comparative analysis of the microstructure and mechanical properties of guided bone regeneration frame membranes made from Ti6Al4V titanium alloy powder using 3D printing technology is presented in this paper. Two different methods were used to produce the samples: direct laser sintering of metals (DMLS) and electron beam melting (EBM). The plates, measuring 30×10×1 mm, were formed from layers 30 µm thick. The surface morphology of the samples was studied at both the micro and macro levels using scanning electron microscopy (SEM) and scanning impulse acoustic microscopy (SIAM). Biocompatibility was assessed both in vitro with mesenchymal stem cell (MSC) cultures and in vivo with laboratory animals. Mechanical properties were evaluated using a three-point bending test, which revealed differences in surface profile depth that was 100 and 150 µm for the DMLS and EBM correspondingly. Samples produced using DMLS technology demonstrated higher strength 2,180±20.7 MPa and elasticity 53,449±200 MPa than those produced by EBM strength 1500±26.1 and elasticity 25,633±125 MPa, according to the results of the mechanical tests. A more active proliferation of MSCs was observed in vitro in the DMLS samples, which was 70% higher compared to EMB and the control group. The bone tissue response to both types of titanium implants was good, with high levels of osseointegration, as confirmed by X-ray microtomography (µCT).

The article is devoted to studying microstructural surfaces of different implant systems that are officially represented on the russian dental market nowadays. The article touches upon the topic of studying microstructural surfaces of different implant systems that are presented on the dental market nowadays. Developed dental implant surface is one of the key factors of a successful osteointegration in bone tissue. Manufacturing companies use different technological methods to get required features. This process is a technological phase in proceeding implants, which can form micro- and nano-cell processes of integrating dental implant into the live bone. Cell and element compound of an implant surface and surface treatment can have an effect on capacity to generate primary matrix, which effects the process of osteointegration.

This article describes a method of directed bone regeneration (DBR) of alveolar bone using 3D printed individual titanium framework membranes (ITFMs). Using computer modelling and additive technologies, we have designed and manufactured ITFMs for directed bone regeneration. The use of such membranes made it possible to reduce the duration of operations and obtain a larger volume of bone regenerate. Barrier membranes made of cross-linked collagen with a long resorption time were used as a comparison group.Results. The use of ICTM for alveolar bone reconstruction allowed us to achieve a maximum bone regenerate height of 6.28 mm, while using Lamina collagen membrane – 2.75 mm. The median difference of bone height before and after surgery with ICTM was 3.605 mm, for Lamina – 1.33 mm. The obtained results allowed us to recommend the use of Lamina membrane for restoration of alveolar bone width and/or height within 3 mm. In case of combined defects of alveolar bone width and height of more than 3 mm, we recommend the use of customized 3D printed titanium frame membranes.

Aim. To demonstrate the results of polymerase chain reaction in real time.Materials and methods. The gum fragment was placed in 1 ml of RNA-leiter ("QIAGEN", Germany), incubated for a day at +4C, samples were stored at -70 °C.To obtain cDNA from the RNA matrix, a ready-made set of reagents MMLV RT Kit ("Eurogen", Russia) was used, the reaction was carried out according to the attached instructions. 2 µl of random decanucleotide primer (Random dN) and 1 µl of sterile RNase-free water were added to 6 µl of RNA, heated at +70C in a “Termit” thermostat (“DNA-Technology”, Russia) for 2 min to melt secondary RNA structures, then stored on ice (+4C). 4 ml of 5X buffer was added to the reaction mixture for the synthesis of the first chain (280 mM Tris-HCl, 375 mM KCl, 30 mM MgCl2, pH 8,7), 2 ml of dNTP mixture, 2 ml of DTT and 2 ml of sterile water free of RNase. Immediately before the reaction, 1 ml of MMLV revertase (reverse transcriptase of mouse leukemia virus) was added to the mixture and added to the RNA. The test tubes were heated in the Gnome thermostat (“DNA- Technology”, Russia) at +39C for 60 minutes, then at +70C for 10 minutes in the “Termit” thermostat (“DNA-Technology”, Russia).Results. The expression of IL-4, IL-10, IL-6, IL-12b, IL-1ß, MMP9 mRNA was not detected in the studied samples. The results of the polymerase chain reaction in real time showed that the expression levels of the proinflammatory cytokine TNFa and TIMP1 genes did not differ in both the autograft group and the collagen membrane group. The expression of MMP 2 and TIMP 2 was higher in the group using a collagen membrane, which is probably associated with tissue regeneration processes.Conclusions. Fibro-guide collagen matrix shows no less effective clinical results in comparison with autografts

Lack of adequate width and thickness of periodontal or peri-implant soft tissues can compromise the aesthetics, function or survival of teeth and dental implants. Biomaterials are widely used in dentistry to overcome the disadvantages of autogenous tissue transplantation. The advantage of using biomaterials is that there is no need for re-surgery and that they are available in large quantities. The most widely used biomaterial for soft tissue augmentation is collagen, as it is believed to best mimic the natural cellular environment of the extracellular matrix, although other biomaterials are also candidates for soft tissue regeneration. Collagen matrices differ in composition, three-dimensional structure, elasticity and mechanical stability. Aim. is to review the literature on the optimization of regeneration at the stages of soft tissue augmentation using a collagen matrix.