## 5 Conclusions  
To design bioactive glass compositions with desirable thermal, mechanical, and bioactive properties as coatings on Ti6 Al4V metallic implants, we investigated a series of four phosphosilicate bioactive glasses based on the 6P55 composition by substituting SiO\({}_{2}\) with B\({}_{2}\)O\({}_{3}\). This substitution aimed to improve adhesion to metallic implants and enhance the physical properties of the glass. Through a combined experimental and simulation study, we elucidated the effect of boron oxide substitution on the glass structure and properties. Computational analysis under the NVT ensemble was used to systematically investigate structural orientation and its impact on key properties within the glass series, including coordination number, \(Q^{\text{n}}\) distribution, bond angle distribution, ring structure, coefficient of thermal expansion (CTE), oxygen speciation, and the percent connectivity of network-forming atoms. These simulations revealed the presence of BO\({}_{3}\) and BO\({}_{4}\) units within the glass structure, forming complex polyhedral networks. Boron's integration into the network broke neighboring Si-Si bonds, capturing electrons and enabling the formation of four-coordinate structures in some cases. Additionally, alkali modifier oxides influenced boron's coordination, shifting it between three- and four-coordinate bonds. Analysis of the ring structure demonstrated a significant reorganization, with a shift towards smaller ring sizes as boron content increased, indicating greater network disruption and reduced polymerization. Thermal analysis via differential scanning calorimetry (DSC), paired with density measurements, provided insights into the impact of boron substitution on the glass transition temperature (\(T_{\text{g}}\)). A decreasing trend in \(T_{\text{g}}\) was attributed to boron's ability to form diverse coordinate bonds, which extended the structural framework and reduced stability, thereby lowering the energy required for bond breakage. This decrease in density with increased boron substitution was linked to differences in ionic and covalent radii, boron's ability to form both three- and four-coordinate complexes, and its lower mass compared to silicon. Further, the substitution of Si-O polyhedra with Si-B polyhedra introduced non-bridging oxygens (NBOs), disrupting the continuous glass network. These changes significantly affected thermodynamic properties and the viscosity of the glass melt. Factors such as modifier composition, temperature, and system pressure influenced \(Q^{n}\) tetrahedra (where \(n=4\), 3, 2, 1, 0, representing the number of bridging oxygens). Molecular dynamics simulations validated by previous studies demonstrated the impact of boron substitution on the thermal expansion of the glass. The calculated CTE values indicated that optimal boron levels enhanced thermal expansion, while excessive or insufficient levels stabilized the network and reduced expansion. This study provides a comprehensive understanding of the interplay between composition, structure, and properties in boron-substituted glass systems. These insights offer valuable guidance for designing glass compositions with tailored properties for biomedical applications and other advanced material systems. Future work intends to focus on extending the investigation of these borosilicate glasses to evaluate their biological performance, including bioactivity, cytocompatibility, and antimicrobial properties. These studies aim to assess the potential of the modified glass compositions for real-world biomedical applications, particularly in orthopedic and dental implants. Additionally, the long-term stability of the coatings and their performance under simulated physiological conditions will be explored to provide a comprehensive understanding of their clinical viability. Insights from these studies will guide the optimization of glass compositions for enhanced biological and mechanical compatibility. Conceptualization, J.-a.N.O. and M.E. ; methodology, J.-a.N.O. and W.X.