![Maximum vertical and lateral load carrying capacity of the bone: The failure limit of the bone due to fatigue is 29 MPa. [Evans et al.] Force: Vertical 920 N Bone Modulus: 10 GPa Force: Lateral 40 N Bone Modulus: 10 GPa Lateral loads cause approximately 25 times higher stresses in the bone than the vertical loads.](https://image.slidesharecdn.com/presentation-1216239001321859-8/85/Presentation-13-320.jpg)
Presentation
- 1. OUTLINE The FEA of the 3.5 mm Bicon Implant-Abutment-Bone system under central occlusal loads Mechanics of the Tapered Interference Fit in a 3.5 mm Bicon Implant
- 2. WHAT IS A DENTAL IMPLANT? Dental implant is an artificial titanium fixture (similar to those used in orthopedics) which is placed surgically into the jaw bone to substitute for a missing tooth and its root(s).
- 3. Surgical Procedure STEP 1: INITIAL SURGERY STEP 2: OSSEOINTEGRATION PERIOD STEP 3: ABUTMENT CONNECTION STEP 4: FINAL PROSTHETIC RESTORATION Success Rates lower jaw, front – 90 – 95% lower jaw, back – 85 – 90% upper jaw, front – 85 – 95% upper jaw, back – 65 – 85%
- 4. History of Dental Implants In 1952, Professor Per-Ingvar Branemark, a Swedish surgeon, while conducting research into the healing patterns of bone tissue, accidentally discovered that when pure titanium comes into direct contact with the living bone tissue, the two literally grow together to form a permanent biological adhesion. He named this phenomenon "osseointegration".
- 5. First Implant Design by Branemark All the implant designs are obtained by the modification of existing designs. John Brunski
- 6. Comparison of Implant Systems Astra Tech. ITI Bicon
- 7. OUTLINE The FEA of the 3.5 mm Bicon Implant-Abutment-Bone system under central occlusal loads Mechanics of the Tapered Interference Fit in a 3.5 mm Bicon Implant
- 8. The FEA of the 3.5 mm Bicon Implant-Abutment-Bone system under central occlusal loads Assumptions: Analyses were linear, static and assumed that materials were elastic, isotropic and homogenous. 100% osseointegration is assumed between bone and implant. Bone and implant are assumed to be perfectly bonded. The stresses in the bone due to the interference fit between implant and abutment is assumed to be relaxed after the insertion of the abutment.
- 9. Finite Element Model 29117 Solid 45 Brick Elements (32000 limit) Symmetry boundary conditions on two cross-sections and fixed in all dofs from the bottom of the bone . V H
- 10. RESULTS Effect of bone’s elastic modulus on the overall stress distribution: Different finite element analyses are run by varying bone mechanical properties surrounding the implant. (1-16 GPa) The properties of the bone depends on the location in the jaw, the gender and age of the patient.
- 11. Force: Vertical 100 N Bone Modulus: 16 GPa Force: Vertical 100 N Bone Modulus: 1 GPa Force: Lateral 20 N Bone Modulus: 16 GPa Force: Lateral 20 N Bone Modulus: 1 GPa
- 12. Both the stress distribution and the stress levels are effected significantly as the bone modulus is varied. CT scan data may be a good source for obtaining patient dependent implant designs.
- 13. Maximum vertical and lateral load carrying capacity of the bone: The failure limit of the bone due to fatigue is 29 MPa. [Evans et al.] Force: Vertical 920 N Bone Modulus: 10 GPa Force: Lateral 40 N Bone Modulus: 10 GPa Lateral loads cause approximately 25 times higher stresses in the bone than the vertical loads.
- 14. OUTLINE The FEA of the 3.5 mm Bicon Implant-Abutment-Bone system under central occlusal loads Mechanics of the Tapered Interference Fit in a 3.5 mm Bicon Implant
- 15. Mechanics of the Tapered Interference Fit in a 3.5 mm Bicon Implant Perfectly elastic large displacement non-linear contact finite element analysis for different insertion depths. Elastic-plastic large displacement non-linear contact finite element analysis for different insertion depths.
- 16. Different implant-abutment assemblies are performed for 0.002”, 0.004”, 0.006”, 0.008” and 0.010” insertion depths. Axisymmetric model is used. 100% osseointegration is assumed between bone and implant. Bone and implant are assumed to be perfectly bonded. Bone is assumed to be elastic, isotropic and homogenous with a Young’s modulus of 10 GPa. Finite Element Model
- 17. Perfectly elastic large displacement non-linear contact finite element analysis for different insertion depths . Contact pressure increases linearly with insertion depth.
- 18. After 0.004” insertion depth, it is seen that plastic deformation occurs in the implant. An elastic-plastic model is needed. Yield Strength of Ti-6Al-4V 139,236 Psi
- 19. Elastic-plastic large displacement non-linear contact finite element analysis for different insertion depths Stress (MPA) % Strain Bilinear Isotropic Hardening Model
- 20. Contact Pressure Distribution for Different Insertion Depths Contact pressure increases non-linearly with larger insertion depths.
- 21. Von Mises Stress Distribution in the Implant Yield Strength of Ti-6Al-4V 139,236 Psi
- 22. Von Mises Stress Distribution in the Bone Yield Strength of Bone 8,702 Psi
- 23. FUTURE WORK Comparison of different implant designs in terms of stress distribution in the bone due to occlusal loads. Modeling non-homogenous bone material properties by incorporating with CT scan data. Comparison of different implant-abutment interfaces