Purpose: To compare the dimensions accuracy and surface roughness of polymeric dental bridges produced by different 3D printers. Design/methodology/approach: Four-part dental bridges were manufactured by three printing systems working on the basis of digital light projection (DLP) stereolithography (SLA), laser-assisted SLA and fused deposition modeling (FDM). The materials used from SLA printers are liquid methacrylate photopolymer resins, while FDM printer use thin wire plastic polylactic acid. The accuracy of the external dimensions of dental bridges was evaluated and the surface roughness was measured. Findings: It was found that compared to the base model, the dimensions of the SLA printed bridges are bigger with 1.25%-6.21%, while the corresponding dimensions of the samples, made by FDM are smaller by 1.07%-4.71%, regardless the position of the object towards the substrate. The samples, produced by FDM, are characterized with the highest roughness. The average roughness deviation (Ra) values for DLP SLA and lase-assisted SLA are 2.40 μm and 2.97 μm, respectively. Research limitations/implications: For production of high quality polymeric dental constructions next research should be targeted to investigation of the polymerization degree, stresses and deformations. Practical implications: Our study shows that 3D printers, based on laser-assisted and DLP SLA, can be successfully used for manufacturing of polymeric dental bridges – temporary restorations or cast patterns, while FDM system is more suitable for training models. The results will help the dentists to make right choice of the most suitable 3D printer. Originality/value: One of the largest fixed partial dentures – four-part bridges, produced by three different commercial 3D printing systems, were investigated by comparative analysis. The paper will attract readers’ interest in the field of biomedical materials and application of new technologies in dentistry.

The aim of this paper is to perform optimization of photopolymerization process of dental composites in order to obtain maximum hardness. Samples (5 mm diameter; 2, 3 and 4 mm thickness) were made of Universal Composite (UC), Bulk fill Composite (BC) and Flowable Composite (FC). Light curing of specimens was performed with 600, 1000 and 1500 mW/cm² light intensity and an irradiation time of 20, 40 and 60 s. Vickers microhardness on the top and bottom surfaces of samples was measured. Optimization was carried out via regression analysis using QStatLab software. Photopolymerization process parameters were calculated using a specially designed MatLab software-based algorithm. For all composites, regression models for hardness on top and bottom surfaces of composite layer were established. Layer thickness as well as hardness on top and bottom surfaces of each composite was calculated for 21 curing modes varying with light intensity and irradiation time. It was established that photopolymerization guidelines only of FC manufacturer guarantee the required hardness, while recommended regimes for UC and BC did not satisfy this requirement. Tables, containing recommended light curing regimes, were developed for three composite types, guaranteeing high hardness of composite restoration. They were designed to facilitate work of dentists in dental offices.

Background: The growing demand for effective methods of bone tissue regeneration highlights the relevance of studying modern bone substitutes and their applications in regenerative medicine. The aim of this work was to conduct a comprehensive analysis of the biological, mechanical, and clinical characteristics of various types of bone substitutes to determine their potential in regenerative medicine. Methods: The study was performed as a systematic literature review in accordance with PRISMA guidelines, analyzing 68 high-quality scientific sources from 2019 to May 2025, using the PubMed, Scopus, Web of Science, and Google Scholar databases. Results: It was established that autogenous grafts exhibit the highest osteogenic properties due to the presence of growth factors BMP-2, BMP-7, and concentrated growth factors; however, their use is limited by donor site morbidity in 20–30% of patients and the requirement to treat 6% of fractures complicated by non-union. Allogeneic and xenogeneic substitutes provide structural support for large defects but require intensive processing in accordance with European Directives 2004/23/EC and 2006/86/EC to minimize the risk of infection transmission. Synthetic substitutes based on calcium phosphate ceramics with pore sizes ranging from 23 to 210 micrometres demonstrate excellent biocompatibility and controlled degradation, with β-tricalcium phosphate exhibiting optimal characteristics for long-term applications compared to calcium sulphate. Conclusions: The findings of the study highlight the necessity of a personalized approach in selecting bone substitutes, considering the specific requirements of medical specialities, and support the development of hybrid biomaterials to combine structural strength with biological activity.

The additive technologies characterize with the building of one layer at a time from a powder or liquid that is bonded by means of melting, fusing or polymerization. They offer a number of advantages over traditional methods: production of complex personalized objects without the need of complex machinery; manufacturing of parts with dense as well as the porous structure and predetermined surface roughness; controllable, easy and relatively quick process. The methods, mostly used in prosthetic dentistry, include stereolithography, selective laser sintering, and selective laser melting. The aim of the present paper is to review the features of the Selective Laser Melting (SLM) process and the possibilities of its application for production of fixed dental prostheses.\ud The features of the SLM process, the microstructure and mechanical characteristics of dental alloys as well as the properties of fixed dental prostheses, fabricated via SLM, were discussed. It was revealed that the SLM Co-Cr dental alloys possess higher mechanical and tribo-corrosion properties, comparatively good fitting ability and higher adhesion strength of the porcelain comparing to the cast alloys. All this is a good precondition for successful application of the SLM process in the production of fixed dental prostheses, mainly of frameworks for metal-ceramic and constructions covered with polymer/composite, intended for areas with high loading

The aim of the present paper is to make a review of the modern trends in the development of the technologies for production of dental constructions. Three are the main trends in production technologies in dentistry last 30 years: digitalization, simulation and implementation of additive technologies. The simulation occurred first and due to the computers development it underwent fast progress from the mathematical calculations and analytical analysis to the 3D modeling and visualization. Thus Computer Aided Engineering (CAE) was developed, allowing dental constructions with optimal design to be produced by optimal technological regimes. \ud The first Computer Aided Design (CAD) – Computer Aided Manufacturing (CAM) systems were created in 1970s as a result of the digitalization. In this mode of operation at first virtual 3D model is generated by CAD, which then is used for production of the real construction by CAM. The CAD-CAM systems allow fabrication of dental restorations which is difficult or impossible to be manufactured by conventional technologies. The development of CAD unit runs from indirect scanning of the plaster model for obtaining data for the 3D model to direct scanning of the prosthesis area. While the development of CAM unit leads to direct manufacturing of the real dental construction using subtractive or additive technologies. The future development of the CAD-CAM systems as a whole characterizes with transition from closed to open access systems, which make them more flexible. \ud In the late 1980sthe new approach to the production of constructions appeared – by addition of material layer by layer. The additive technologies were developed. They characterize with building of one layer at a time from a powder or liquid that is bonded by means of melting, fusing or polymerization. Stereo lithography, fused deposition modeling, selective electron beam melting, laser powder forming and inkjet printing are the methods, mostly used in dentistry. Due to the great variety of the additive manufacturing processes various materials can be used for production of different dental constructions for application in many fields of dentistry.\ud The simulation, digitalization and implementation of additive technologies in dentistry led to fast development of the technologies for production of dental constructions last decade. As a result many of manual operations were eliminated, the constructions’ accuracy increased and the production time and costs decreased

The aim of the present paper is to make a review of the properties of dental alloys, fabricated using Additive Technologies (AT). The microstructure and mechanical properties of Co-Cr alloys as well as the accuracy and surface roughness of dental constructions are discussed. In dentistry two different approaches can be applied for production of metal frameworks using AT. According to the first one the wax/polymeric cast patterns are fabricated by 3D printing, than the constructions are cast from dental alloy with as-printed patterns. Through the second one the metal framework is manufactured form powder alloy directly from 3D virtual model by Selective Electron Beam Melting (SEBM) or Selective Laser Melting (SLM). The microstructure and mechanical properties of Co-Cr dental alloys, cast using 3D printed patterns, are typical for cast alloys. Their dimensional and adjustment accuracy is higher comparing to constructions, produced by traditional lost-wax casting or by SLM. The surface roughness is higher than that of the samples, cast by conventional technology, but lower comparing to the SLM objects. The microstructure of SLM Co-Cr dental alloys is fine grained and more homogeneous comparing that of the cast alloys, which defines higher hardness and mechanical properties, higher wear and corrosion resistance.