###### Abstract  
The osseogeintegration in/around additively manufactured (AM) lattice structures of a new titanium alloy, Ti-19 Nb-14 Zr, was evaluated. Different lattices with increasingly high sidewalls gradually closing them were manufactured and implanted in sheep. After removal, the bone-interface implant (BII) and bone-implant contact (BIC) were studied from 3D X-ray computed tomography images. Measured BII of less than 10 \(\upmu\)m and BIC of 95% are evidence of excellent osseointegration. Since AM naturally leads to a high-roughness surface finish, the wettability of the implant is increased. The new alloy possesses an increased affinity to the bone. The lattice provides crevices in which the biological tissue can jump in and cling. The combination of these factors is pushing ossification beyond its natural limits. Therefore, the quality and speed of the ossification and osseointegration in/around these Ti-19 Nb-14 Zr laterally closed lattice implants open the possibility of bone spline key of prostheses. This enables the stabilization of the implant into the bone while keeping the possibility of punctual hooks allowing the implant to be removed more easily if required. Thus, this new titanium alloy and such laterally closed lattice structures are appropriate candidates to be implemented in a new generation of implants. osceointegration; animal surgery; implants; lattices; titanium alloy; additive manufacturing (AM); X-ray computed tomography (XCT) 2023201372820137 In the present work, specimens with the same geometrical configuration (same CAD, same shape and size of the lattice cells) as the previous work and a new-patented titanium alloy for implant Ti-19 Nb-14 Zr [7], called ZTM14N, containing niobium (Nb) and zirconium (Zr) instead of Al and V were investigated. This material, studied from a mechanical point of view by the French National Center for Scientific Research (CNRS) according to ASTM standards [8], reveals very interesting mechanical properties, as shown in Appendix A. For example, it has a lower elastic modulus (38 GPa) than other titanium alloys (100 to 130 GPa for Ti6 Al4V [9]). In addition, it contains highly biocompatible materials [10] and is highly resistant to corrosion [11; 12]. According to [PERSON] et al. [11; 12], ZTM14N is ten times more resistant to inflammation than Ti6 Al4V. Such properties make the ZTM14N alloy the best alternative material for the medical market. Indeed, a significant stiffness mismatch between the human bone (25-30 GPa) and the implant material causes a stress effect that leads to bone resorption. Bone resorption can be detrimental when the degradation of existing bone predominates over bone formation. Furthermore, the release of both V and Al ions from Ti6 Al4V in the human body might cause long-term health problems, such as peripheral neuropathy, osteomalacia, and Alzheimer's disease [13; 14]. In addition, the duration of the implantation concerned two sheep and lasted twelve weeks instead of eight weeks in the previous study. This longer residence time is the classical duration fracture consolidation. Finally, the specimens are surrounded by increasingly high sidewalls gradually closing the lattice structures. The purpose of this new study was twofold. First, the study of the contact between the bone and the implant from two points of view: (1) the bone-interface implant (BII), i.e., the interface thickness between bone and implant surfaces, and (2) determined from BII, the bone-implant contact (BIC), i.e., the proportion of the implant surface in contact with bone. Second, the study of the bone progression in depth as a function of the lattice access, as well as a function of bone location in the body (tibia or metatarsal bone). The histomorphometry of the BIC, i.e., the ratio of bone over metal, is traditionally performed by microscopy on prepared glass slides, and it is by nature two-dimensional (2D). In this work, the study is performed on XCT images segmented implementing machine learning (ML) algorithms.