Biomechanical effects of offset placement of dental implants
Biomechanical effects of offset placement of dental implants in the edentulous posterior mandible
Abstract
Background
Proper implant placement is very important for long-term implant stability. Recently, numerous biomechanical studies have been conducted to clarify the relationship between implant placement and peri-implant stress. The placement of multiple implants in the edentulous posterior mandible has been studied by geometric analysis, three-dimensional finite element analysis (FEA), model experimentation, etc. Offset placement is a technique that reduces peri-implant load. However, few studies have used multiple analyses to clarify the value of the offset placement under identical conditions.
The present study aimed to clarify the biomechanical effects of offset placement on the peri-implant bone in edentulous posterior mandibles by comparative investigation using FEA and model experimentation with strain gauges.
Methods
Three implants were embedded in an artificial mandible in the parts corresponding to the first premolar, the second premolar, and the first molar. A titanium superstructure was mounted to prepare models (experimental models). Three load points (buccal, central, and lingual) were established on the part of the superstructure corresponding to the first molar. Three types of experimental models, each with a different implant placement, were prepared. In one model, the implants were placed in a straight line; in the other two, the implants in the parts corresponding to the second premolar and the first molar were offset each by a 1-mm increment to the buccal or lingual side. Four strain gauges were applied to the peri-implant bone corresponding to the first molar.
The experimental models were imaged by micro-computed tomography (CT), and FEA models were constructed from the CT data. A vertical load of 100 N was applied on the three load points in the experimental models and in the FEA models. The extent of compressed displacement and the strain in the peri-implant bone were compared between the experimental models and the FEA models.
Results
Both experimental and FEA models suffered the least compressed displacement during central loading in all placements. The greatest stress and compressive strain was on the load side in all types of placements.
Conclusions
Offset placement may not necessarily be more biomechanically effective than straight placement in edentulous posterior mandibles.
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