# Microstructural Evaluation of Dental Implant Success Using Micro-CT: A Comprehensive Review
## 3 Critical Bone Microstructure Parameters for Implant Success  
The long-term success of dental implants is contingent upon their stability within the oral cavity [9]. Implant stability is a critical factor influencing the functionality, aesthetic appeal, and patient satisfaction associated with implant restorations. Stable dental implants facilitate effective mastication and speech while maintaining the integrity of the surrounding bone and soft tissue [38]. Osseointegration is defined as the process of creating a robust connection between the bone and the implant surface through the formation of new bone tissue. The success of osseointegration is contingent upon a number of factors, including the design of the implant, the characteristics of the surface, the surgical technique employed, and the characteristics of the bone in which the implant is placed (host factors) [9]. The use of micro-CT enables the evaluation of multiple bone microstructure parameters that are crucial for osseointegration and implant stability. These include bone volume fraction (BV/TV [%)], bone surface (BS/TV), trabecular bone (Tb. Th, Tb. N, Tb. Sp, and Tb. Pf), connectivity density (Conn. D [1/mm\({}^{3}\)]), structure model index (SMI), and degree of anisotropy (DA) [39; 40; 41]. Bone volume fraction (BV/TV) is defined as the ratio of bone volume (BV) to total volume (TV) and serves as a fundamental indicator of bone density [39]. The study conducted by [PERSON] et al. (2021) demonstrated a positive correlation between the BV/TV, insertion torque value (ITV), and implant stability quotient (ISQ) values. These findings suggest that higher BV/TV is associated with enhanced implant stability, thereby establishing BV/TV as a potential indicator for predicting the success of dental implants [42]. The study demonstrated a significant correlation between bone density (measured in Hounsfield units) and implant ultimate stability. The findings indicated that denser bone resulted in superior stability outcomes, while increased BV/TV was associated with a higher percentage of newly formed bone, which directly impacted implant stability. Furthermore, bone density and cortical thickness were identified as crucial predictive parameters for selecting the optimal surgical technique and implant type to enhance stability [43; 44; 45]. The trabecular examination includes trabecular thickness (Tb. Th), trabecular separation (Tb. Sp. ), trabecular number (Tb. N), and trabecular pattern factor (Tb. Pf). These three components provide an in-depth understanding of the bone architecture [39]. The correlation between Tb. Th measurements and the mechanical strength of bone is of paramount importance, as Tb. Th serves as a pivotal factor influencing bone microarchitecture, as well as the overall quality of bone. Empirical studies suggest that diminished Tb. Th is associated with an elevated risk of fractures and a reduction in the mechanical integrity of bone. Research indicates that a reduction in Tb. Th correlates with a diminished bone volume fraction and a decline in bio-mechanical properties, including Young's modulus and toughness, thereby suggesting a compromise in bone strength [46]. Tb. N is a principal indicator of bone microarchitecture complexity and connectivity. A reduction in Tb. N with age has been demonstrated in numerous studies, indicating a potential for diminished bone strength and heightened fracture risk in older individuals [47; 48]. Tb. N and other trabecular parameters exhibit variation across different skeletal sites and populations, reflecting the influence of factors such as activity levels, subsistence strategies, and loading patterns [49; 50]. Tb. Sp is a measure employed in bone histomorphometry for the evaluation of the structure of trabecular (or spongy) bone. Trabecular bone constitutes the porous inner part of bones, which can be found at the ends of long bones and in the vertebrae [51]. An increase in porosity results in a greater number of voids and a reduction in solid bone material. Tb.