Influence of the roughness of dental implants obtained by additive manufacturing on osteoblastic adhesion and proliferation: A systematic review

Vitamin D3-Coated Surfaces and Their Role in Bone Repair and Peri-Implant Biomechanics

Dental rehabilitation with titanium implants may requires the optimization of techniques and materials when oral conditions affect the successful treatment result. Thus, this study aims to customize the surface of titanium implants with bioactive vitamin D3 molecules to increase the performance of bone repair. The surfaces were functionalized following the "dip-coating" incorporation method with vitamin D3 in a solution of 1000 I.U./goat. The work was carried out in two stages: (I) physicochemical and biological tests (in vivo) in order to characterize and validate the vitamin D3 surface as well as its ability to affect peri-implant bone biomechanics; and (II) in vitro experiments to characterize viability responses, interaction and cell mineralization capacity. Scanning electron microscopy showed that the creation of vitamin D3 films is stable and homogeneous, while the in vivo results showed an increase in the biomechanical and microarchitectural capacity of the bone when vitamin D3 implants were used. Furthermore, the application of functionalized surfaces proved effective in promoting cell interaction and bone mineralization processes while preserving cell viability and capacity. In conclusion, the delivery of bioactive molecules based on vitamin D3 promotes changes in the surface microstructure of titanium, enabling an increase in the structural characteristics of bone tissue that result in an improvement in bone repair and peri-implant biomechanics.

Current Perspectives on Additive Manufacturing and Titanium Surface Nanotopography in Bone Formation

This study aimed to assess the impact of manufacturing methods (conventional and additive manufacturing) and surface treatments (polished and nanotopographic) on the physicochemical properties of Ti6Al4V alloy and their correlation with osteoblast cellular behavior. The evaluated groups were Machined Discs (MD), Machined Discs with Treatment (MD-WT), Additive-manufactured Discs (AD), and Additive-manufactured Discs with Treatment (AD-WT). Surface analyses included SEM, AFM, surface roughness, EDS, XRD, surface free energy, and zeta potential. MC3T3-E1 cells were cultured for biological assessments, including cell morphology, viability, gene expression, alkaline phosphatase activity, and mineralization. ANOVA and Holm-Sidak tests were applied (p < 0.05). MD exhibited grooved topography, AD had partially fused spherical particles, while MD-WT and AD-WT showed patterns from chemical treatment (H3PO4 + NaOH). EDS identified additional ions in MD-WT and AD-WT. XRD patterns indicated crystal lattice orientation differences. MD-WT and AD-WT displayed higher surface free energy than MD and AD (p < 0.05). AD had greater roughness (Sa 6.98 μm, p < 0.05). Biological analyses revealed higher cell viability for MD and AD (p < 0.001), higher ALP activity in MD, and lower in AD-WT. Gene expression varied, with MD showing higher Alpl, Ibsp, and Bglap (p < 0.001), and AD-WT showing higher Runx2 (p < 0.001). Mineralized matrix behavior was similar for MD, AD, and MD-WT (p > 0.05). MD and AD surfaces demonstrated superior osteogenic differentiation potential, while AD exhibited greater roughness, lower surface free energy, higher cell viability, and osteoblastic differentiation potential.

Atomic Interaction S. aureus/Machined and Additive Manufacturing Ti-6Al-4V and Ti-35Nb-7Zr-5Ta Disks for Dental Implants

The adhesion strength of a bacterial strain on a substrate influences colonization and biofilm development, so the biomolecular analysis of this interaction is a step that allows insights into the development of antifouling surfaces. As peri-implantitis is the main cause of failure of implant-supported oral rehabilitations and the dental literature presents gaps in the atomic bacteria/surface interaction, this study aimed to correlate the qualitative variation of roughness, wettability, chemical composition, and electrical potential of Ti-6Al-4V and Ti-35Nb-7Zr-5Ta (TNZT) disks obtained by machining (M) and additive manufacturing (AM) on the colonization and adhesion strength of S. aureus quantified by atomic force microscopy (AFM). The samples were evaluated for roughness, electrical potential, and S. aureus colonization and adhesion strength by specific methods in the AFM with subsequent analysis in the NanoScope software analysis, wettability by sessile drop method, and chemical composition by energy dispersive x-ray spectroscopy (EDX). Qualitative data were correlated with bacterial adhesion strength. The greater adhesion strength of S. aureus was observed in descending order for TNZT AM, TNZT M, Ti-6Al-4V AM, and Ti-6Al-4V M. This experimental in vitro study allowed us to conclude that for the evaluated groups, the strength adhesion of S. aureus showed a linear relationship with roughness, and nonlinear for wettability, electrical potential, and S. aureus colonization on the surfaces evaluated. As for the two variation factors, type of alloy and manufacturing method, those that promoted the lowest bacterial adhesion strength were Ti-6Al-4V and M, possibly attributed to the synergistic modification of the evaluated surface properties. Thus, this study suggests S. aureus preferences for rough, hydrophilic surfaces with a greater electrical potential difference.

Chitosan coatings on titanium-based implants - From development to characterization and behavior: A systematic review

Chitosan is a promising natural polymer for coatings, it combines intrinsic antibacterial and pro-osteoblastic properties, but the literature still has a gap from the development to behavior of these coatings, so this systematic review aimed to answer, "What is the relationship between the physical and chemical properties of polymeric chitosan coatings on titanium implants on antibacterial activity and osteoblast viability?". PRISMA guidelines was followed, the search was applied into 4 databases and grey literature, without the restriction of time and language. The selection process occurred in 2 blinded steps by the authors. The criteria of eligibility were in vitro studies that evaluated the physical, chemical, microbiological, and biological properties of chitosan coatings on titanium surfaces. The risk of bias was analyzed by the specific tool. Of 734 potential articles 10 were included; all had low risk of bias. The coating was assessed according to the technique of fabrication, FT-IR, thickness, adhesion, roughness, wettability, antibacterial activity, and osteoblast viability. The analyzed coatings showed efficacy on antibacterial activity and cytocompatibility dependent on the class of material incorporated. Thus, this review motivates the development of time-dependent studies to optimize manufacturing and allow for an increase in patents and availability on the market.

Enhanced osteointegration and osteogenesis of osteoblast cells by laser-induced surface modification of Ti implants

Dental and orthopedic implants have become routine medical technologies for tooth replacement and bone fixation. Despite significant progress in implantology, achieving sufficient osseointegration remains a challenge, often leading to implant failure over the long term. Nanotechnology offers the potential to mimic the natural patterns of living tissues, providing a promising platform for tissue engineering and implant surface design. Among the various methods for developing nanostructures, High-Regular Laser-Induced Periodic Surface Structures (HR-LIPSS) techniques stand out for their ability to fabricate highly ordered nanostructures with excellent long-range repeatability and production efficiency. In this study, we utilized an innovative technical approach to generate traditional laser-induced superficial LIPSS nanostructures, followed by detailed surface analysis using classical microscopy and physicochemical methods. Our findings demonstrate for the first time that nanostructured LIPSS surfaces can significantly enhance cell adhesion and proliferation while providing an optimal environment for cell metabolism. Given the high reproducibility, low cost, and potential of HR-LIPSS techniques to support cell growth and differentiation, this novel technology has the potential to impact both the industrial development of new implants and clinical outcomes after implantation.