Comparative Evaluation of Primary Stability in Two Different Implant Systems Using Resonance Frequency Analysis Device

Introduction: Primary stability is a critical determinant of successful osseointegration and long-term survival of dental implants. Implant design and surface characteristics influence stability outcomes, making comparative evaluations clinically relevant. This study assessed the primary stability of Nobel ActiveTM and i Fix Pro implants using resonance frequency analysis (RFA) and explored factors affecting it.Methods: A comparative analytical study was conducted at the Department of Periodontology and Oral Implantology, Kantipur Dental College, Nepal, from August 2025 to January 2026 after ethical approval from the Institutional Review Committee. Thirty implants were placed in eligible participants with equal allocation based on feasibility and clinical judgment. Primary stability was measured immediately after placement using the Osstell Beacon™ device, expressed as Implant Stability Quotient (ISQ) values. Data were analyzed using the chi-square test, independent t-test, and multiple linear regression, followed by post hoc power analysis. The level of statistical significance was set at p<0.05.Results: Baseline characteristics were comparable between groups, including age (39.81±11.32 vs. 44.50±12.32 years) and sex distribution (46.67% male, 53.33% female). Mean ISQ values was 73.00±9.91 for i-Fix Pro and 75.22±8.24 for Nobel ActiveTM (p = 0.51). Regression analysis identified bone density D3 as the only significant predictor of reduced stability (B = –10.99; 95% CI :–20.37 -1.60), p = 0.02). Conclusions: Both implant systems achieved comparable primary stability. Bone density was the critical determinant, while other patient and implant variables were not significant. Cost-effective systems such as i Fix Pro may provide stability outcomes similar to premium systems under appropriate clinical conditions, supporting their use in resource-conscious settings.