Evaluation of primary stability of implants in bovine bone defects models

This study assessed initial stability using Resonance Frequency Analysis (RFA) and Damping Capacity Analysis (DCA) devices in three different bone conditions: a control group without bone defects, a cortical bone defect model, and a cancellous bone defect model. Additionally, the correlation between Implant Stability Quotient (ISQ) and Implant Stability Test (IST) values was investigated. This in vitro study utilized a controlled experimental design with bovine rib specimens. Thirty implants were placed in specimens divided into three groups (n = 10): no defect (Group A), cortical bone defect (Group B), and cancellous bone defect (Group C). Implant stability was measured using RFA and DCA devices. ISQ and IST values in Group A were 84.83 ± 1.38 and 86.52 ± 1.73, respectively; in Group B, they were 64.20 ± 4.87 and 64.25 ± 5.26, respectively; and in Group C, they were 82.80 ± 5.74 and 86.47 ± 4.01, respectively. Statistical analyses were performed using Kruskal-Wallis test with Bonferroni test to compare differences among groups, and Spearman's correlation analysis was used to evaluate the relationship between ISQ and IST values. A significant reduction in ISQ(p < 0.001) and IST(p < 0.001) values was observed in the cortical bone defect group. In contrast, the cancellous bone defect group showed no significant difference from the control group (ISQ: p = 0.493, IST: p = 0.594). ISQ and IST values exhibited a significant positive correlation (r = 0.798, p < 0.001), and stability values varied significantly with measurement direction. This study confirmed that cortical bone defects significantly reduced primary stability, whereas cancellous bone defects had no significant impact when cortical bone was sufficient. Additionally, ISQ and IST values showed a strong positive correlation, indicating that both methods provide consistent assessments of implant stability.