A combined experimental and numerical study on titanium porous microstructures intended to interface the bone tissue and the solid homogeneous part of a modern dental implant is presented. A specific class of trabecular geometries is compared to a gyroid structure. Limitations associated with the application of the adopted selective laser melting technology to small microstructures with a pore size of 500 $\mathsf{\mu }$m are first examined experimentally. The measured effective elastic properties of trabecular structures made of Ti6Al4V material support the computational framework based on homogenization with the difference between the measured and predicted Young’s moduli of the Dode Thick structure being less than 5%. In this regard, the extended finite element method is promoted, particularly in light of the complex sheet gyroid studied next. While for plastic material-based structures a close match between experiments and simulations was observed, an order of magnitude difference was encountered for titanium specimens. This calls for further study and we expect to reconcile this inconsistency with the help of computational microtomography.

The objective of this study was to compare the distribution of stress in the maxillary bone, dental implants, and prosthetic components supporting implant-supported maxillary overdentures with partial palatal coverage, in both splinted and unsplinted designs. Two models of maxillary overdentures were designed using the Exocad Dental CAD program, which included cancellous and cortical bone. The complete denture design and abutments (locator abutments in the unsplinted and Hader bar with Vertix attachments placed distally in the splinted variant) were also designed. The denture material was PEEK (Polyetheretherketone), and the method used to analyze patient-specific 3D X-ray scans was 3D QCT/FEA (three-dimensional quantitative computed tomography-based finite element analysis). Loading was divided into three load cases, in the frontal region (both incisors of the denture) and distal region (both molars and first premolar of the denture). The forces applied were 150 N with an oblique component with a buccal inclination of 35° in the frontal region, and 600 N with a buccal inclination of 5° (molars) or solely vertical (premolar) in the distal region. The model with locator abutments showed higher stresses in all load cases in both analyzed implant variants and in the maxilla. The differences in stress distribution between the splinted and unsplinted variants were more significant in the distal region. According to the results of the present study, the amount of stress in bone tissue and dental implant parts was smaller in the splinted, bar-retained variant. The findings of this study can be useful in selecting the appropriate prosthetic design for implant-supported maxillary overdentures with partial palatal coverage.

Biological tissues belong to the group of materials highly dependent on its micro structure. A variety of results may be found in the study of human teeth whose local composition and mechanical characteristics show considerable variations. The article deals with the measurement of elastic micromechanical characteristics in the root part of human tooth dentin. An extracted tooth was analyzed in two typical directions, i.e. longitudinal (from the tooth crown-neck to the root) and transverse (in the middle of the root part). Values of the modulus of elasticity in walls of the tooth root in the longitudinal and transverse directions were identified by means of nanoindentation. The development of the modulus of elasticity was measured in several parallel rows proceeding from the outer edge of the tooth root towards the root canal. The values measured in the dentin part of the tooth root ranged around ~17 GPa (cement-dentin boundary), ~23 GPa (middle part of dentin) and ~14 GPa (dentin-root part interface). In the longitudinal section, the value of the modulus of elasticity was almost constant in the majority of tested volume (~18 GPa) with some deviations in peripheral part (end of the root) due to changes in microstructural orientation from sagittal plane. The differences revealed a low degree of anisotropy of dentin.

3D printing of beta titanium alloys for biomedical applications is currently in great demand, both for material reasons and for the possibility of producing very complex replacements, often directly tailored to the patient. Gyroidal and similar structures are ideal for biomedical replacements but their manufacturing require specific additive technology and post-processing like annealing or etching. The aim of this work is to determine the mechanical properties of Ti25Nb4Ta8Sn alloy which overcomes Ti6Al4V in biomedical applications. The results showed that Ti6Al4V exhibited a significantly higher ultimate tensile strength (up to 1200 MPa) compared with the beta titanium alloy Ti25Nb4Ta8Sn (up to 360 MPa), while the latter demonstrated a substantially lower elastic modulus (∼40–50 GPa), beneficial for biomedical applications. Annealing improved strength and reduced internal stresses in both alloys, while etching effectively removed residual powder but slightly decreased mechanical integrity. These findings provide a quantitative basis for optimizing printing and post-processing parameters of beta titanium alloys for implant design. The properties will be used for future numerical simulations of implants made from Ti25Nb4Ta8Sn alloy based on discrete particle grid models.

It is important to know the mechanical and micromechanical characteristics of conventional dental implants in order to design and develop novel dental implants and surface treatments that ensure a good biomechanical stability and almost fully replace the biological tissue. A successful integration of the implant depends on its chemical, mechanical and physical properties and the quality of the bone tissue. Considering these facts, we developed two novel variants of dental implant stems with an anti-rotational geometrical solution. On these variants, we have then performed numerical analyses of static strength. Outcomes of simulations vary depending on the type of the implant and load mode.

In recent years, 3D printing has become a key technology for producing intricate geometries with high precision. Beta titanium alloys (β-Ti), due to their excellent combination of strength, ductility, low elastic modulus, and biocompatibility, are widely used in the aerospace and medical industries. However, the unique microstructure formed during additive manufacturing characterised by porosity, residual stress, and anisotropy can significantly influence the mechanical performance and durability of these materials. This study examines how different printing parameters affect porosity, dimensional stability, and mechanical properties in the β-Ti alloy Ti25Nb4Ta8Sn. The investigation focuses on thin-walled samples and gyroid structures, which represent model geometries for porous biomedical components. These structures, defined by a periodic network of interconnected channels, provide a useful platform for studying the relationship between geometry and mechanical response. In addition, the effects of surface etching on the morphology and compressive behaviour of printed gyroid structures were evaluated. Compression testing was used to determine how etching alters load-bearing performance and to identify correlations between surface modification and mechanical response. The combined analysis enables optimisation of both printing and post-processing parameters for advanced biomedical applications.