Discussion : Biomechanical effects of offset placement of dental implants (1)
Discussion
Experimental models
Reported studies verifying the effects of offset placement include ones where implant bodies were embedded in rectangular experimental models, ones where rectangular bone models were constructed with FEA models, and ones where FEA models were constructed from CT data on human mandibles. The artificial mandible models used in the present study were type II in the Lekholm and Zarb classification and created using clinically valid estimates of bone quality, bone structure, and bone morphology. If the effects of implant placement alone are being verified, then models that are simple in form can be used. However, artificial mandibles were used in the present study in order to take into account the constraints on offset amounts due to anatomical morphology, the differences in stress distribution in the surrounding bone due to bone morphology, and other aspects of clinical practice.
FEA models
Analysis was done with FEA models, in which the cancellous bone was simplified as being a homogeneous body. FEA models have been reported to be useful for verifying the behavior of implants when loaded, and so, the effects of different placements were verified with FEA models and compared with the results from the experimental models. In a previous study, Omori et al. compared the compressed displacement between experimental models and FEA models to verify the validity of the FEA models. They reported that the constraint conditions in the artificial mandible bottom and differences in the actual Young’s modulus were two reasons why the two models produced different absolute values for the compressed displacement. In order to apply the actual Young’s modulus to the FEA models in the present study, FEA models with a known Young’s modulus were created and the resulting values of compressed displacement were compared with the results from the experimental models; after the appropriate Young’s modulus was found, the FEA models were created again for further analysis.
Serial posts:
- Biomechanical effects of offset placement of dental implants
- Background : Biomechanical effects of offset placement of dental implants
- Methods : Biomechanical effects of offset placement of dental implants (1)
- Results : Biomechanical effects of offset placement of dental implants (1)
- Methods : Biomechanical effects of offset placement of dental implants (2)
- Methods : Biomechanical effects of offset placement of dental implants (3)
- Methods : Biomechanical effects of offset placement of dental implants (4)
- Results : Biomechanical effects of offset placement of dental implants (2)
- Discussion : Biomechanical effects of offset placement of dental implants (1)
- Discussion : Biomechanical effects of offset placement of dental implants (4)
- Discussion : Biomechanical effects of offset placement of dental implants (2)
- Discussion : Biomechanical effects of offset placement of dental implants (3)
- Discussion : Biomechanical effects of offset placement of dental implants (5)
- References : Biomechanical effects of offset placement of dental implants
- Figure 1. An artificial mandible
- Figure 2. Three implants were embedded in an artificial mandible
- Figure 3. Three different models with different placements
- Figure 4. Experimental model. (a) Buccal load, (b) central load, and (c) lingual load
- Figure 5. Application of strain gauges
- Figure 6. Loading test in the experimental model
- Figure 7. A finite element analysis (FEA) model
- Figure 8. The displacement of the implants under loading in experimental models
- Figure 9. The displacement of the implants under loading in finite element analysis (FEA) models
- Figure 11. The strain around the no. 36 implant in the experimental models
- Figure 12. The strain around the no. 36 implant
- Figure 13. The distribution of equivalent stress around the peri-implant bone
- Figure 14. The distribution of equivalent stress around the no. 36 implant
- Figure 15. Load supporting area in the superstructures
- Table 1 Mechanical properties of materials used in the FEA models
- Table 2 Means and standard deviations (SD) of displacement of the implants
- Table 3 Means and standard deviations (SD) of displacement of the implants
- Table 4 Means and standard deviations (SD) of strain around the no. 36 implant
- Table 5 Tukey’s test for strain B in the experimental models
- Table 6 Tukey’s test for strain L in the experimental models
- Table 7 Means and standard deviations (SD) of strain around the no. 36 implant
- Table 8 Tukey’s test for strain B in the FEA models
- Table 9 Tukey’s test for strain L in the FEA models