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فارسی

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Vibration-Based Assessment of Dental Implants: A Finite Element Study on Bone Quality and Boundary Conditions

Authors :

Fatima Wayzani¹ Mohammadjavad (Matin) Einafshar² Ata Hashemi³

1- Amirkabir University of Technology 2- Aalborg University, Denmark 3- Amirkabir University of Technology

Keywords :

Modal analysis،Dental implant stability،Natural frequency،Boundary constraints،Bone quality،Bone substitute materials

Abstract :

Background: Dental implant stability is critical to the long-term success of implantology, as it is influenced by factors such as bone quality, implant design, and boundary conditions. Modal analysis offers a non-invasive method to assess implant stability by evaluating the natural frequency of the implant system. Objectives: To investigate the natural frequency of dental implants under different boundary constraints, mandible sizes, bone qualities, and the presence of a bone substitutive layer. Materials and Methods: Modal analysis was performed on a three-dimensional finite element model of a biphasic healing titanium dental implant and mandibular bone. Both "long" and "short" mandibular geometries were considered. Three boundary conditions were applied, and the influence of different bone qualities (types I, II, III, and IV) was examined. The effect of bone substitutive layers (magnesium phosphate, hydroxyapatite, PMMA) with varying thicknesses (300 μm and 800 μm) was also assessed. Results: The natural frequency of the dental implant system was significantly higher in the "short" mandible model (13,959 Hz, 14,332 Hz, and 15,111 Hz for the first three modes) compared to the "long" mandible model (3,826 Hz, 6,851 Hz, and 7,565 Hz for bone type IV). Increasing the number of boundary constraints led to an increase in natural frequency, with the first mode frequency rising from 1,786 Hz (one side fixed) to 5,650 Hz (three sides fixed) for bone type IV. The highest natural frequencies were observed in bone type I (65,204 Hz, 82,039 Hz, and 83,958 Hz for the first three modes in the short mandible model). The presence of a bone substitutive layer, regardless of material type or thickness, had a negligible impact on natural frequency, with variations of less than 1% compared to the control model. Conclusions: For a successful dental implantology process, primary stability should be verified before surgery. Bone quality significantly affects implant stability, with higher natural frequencies observed in denser bone. Bone substitutive materials, while important for osseointegration, do not markedly affect the implant's natural frequency when applied in thin layers.