# Finite Element Analysis (FEA) for the Evaluation of Retention in a Conometric Connection for Implant and Prosthesis

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## Abstract

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## 1. Introduction

## 2. Materials and Methods

- Model creation: Start by digitally modeling the structure or part to be analyzed. This model is divided into smaller parts known as finite elements. Finite elements are simple geometric shapes, such as triangles or quadrilaterals in two dimensions 2D and tetrahedra or hexahedra in three dimensions 3D.
- Definition of material properties: Each finite element is assigned material properties, including Young’s modulus, Poisson’s coefficient, strength, and other characteristics depending on the material of the part.
- Application of loads: Define loads, such as forces, moments, pressures, constraints, and boundary conditions, to simulate the real environment in which the structure operates.
- Discretization: The model is divided into finite elements, and the nodes of these elements are assigned unknown variables like displacements, stresses, or other relevant quantities. Subsequently, the load/constraint conditions are assigned, and the results are analyzed.

## 3. Results

## 4. Discussion

## 5. Conclusions

- There existed a linear relationship between the cap activation force and retentive force.
- The analytical method proposed by Bozkaya and Muftu [19] underestimated the system retention.
- The FEA method demonstrated comparable results with in vitro studies. For a connection with a 4° conicity, the retentive force obtained from in vitro studies was 68 N, while with FEA, it was 66 N.
- The force required to activate the connection in the case of a 4° taper was approximately 30 N. Values below 20 N of activation force did not guarantee the required retention.
- The inclination of the abutment decreased the retention of the system. To counteract this effect, it was necessary to increase the activation force by 10 N for abutments inclined between 15° and 30°.
- The state of stress acting on the system was greater in the case of inclined abutments.

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 4.**Three-dimensional 3D model of the abutment–cap–crown system inclined at 15° (on the

**left**) and 30° (on the

**right**).

**Figure 6.**Contact with friction (shown in red) was modeled between the cap and abutment with a coefficient of friction set to 0.3 [30].

**Figure 7.**On the

**left**is the constraint configuration and on the

**right**is the application of the load on the zirconia crown.

**Figure 11.**The von Mises stress distribution on the system under an insertion force of 30 N (

**first line**) and 60 N (

**second line**).

**Figure 13.**The retention force as a function of the taper of the system under an insertion load of 30 N.

**Figure 14.**The von Mises stress distribution on the abutment inclined at 15° under insertion forces of 10 N (

**first line**), 30 N (

**second line**), and 60 N (

**third line**).

**Figure 15.**The von Mises stress distribution on the abutment inclined at 30° under insertion forces of 10 N (

**first line**), 30 N (

**second line**), and 60 N (

**third line**).

**Figure 16.**The trend of the removal force as a function of the insertion force for abutments inclined at 0°, 15°, and 30°.

Young’s Modulus (GPa) | Poisson’s Ratio | Tensile Yield Strength (MPa) | Tensile Ultimate Strength (MPa) | |
---|---|---|---|---|

Titanium (Ti6Al4V cap and abutment) | 110 | 0.3 | 830 | 900 |

Zirconia (crown) | 200 | 0.31 | 330 | 551 |

Insertion Force (N) | Displacement of Coping (mm) | Von Mises Stress (MPa) |
---|---|---|

0 | 0.00273 | 506.01 |

20 | 0.00546 | 508.52 |

30 | 0.00819 | 511.73 |

40 | 0.01092 | 530.56 |

50 | 0.01365 | 570.34 |

60 | 0.01638 | 594.08 |

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**MDPI and ACS Style**

Ceddia, M.; Comuzzi, L.; Di Pietro, N.; Romasco, T.; Specchiulli, A.; Piattelli, A.; Trentadue, B.
Finite Element Analysis (FEA) for the Evaluation of Retention in a Conometric Connection for Implant and Prosthesis. *Osteology* **2023**, *3*, 140-156.
https://doi.org/10.3390/osteology3040015

**AMA Style**

Ceddia M, Comuzzi L, Di Pietro N, Romasco T, Specchiulli A, Piattelli A, Trentadue B.
Finite Element Analysis (FEA) for the Evaluation of Retention in a Conometric Connection for Implant and Prosthesis. *Osteology*. 2023; 3(4):140-156.
https://doi.org/10.3390/osteology3040015

**Chicago/Turabian Style**

Ceddia, Mario, Luca Comuzzi, Natalia Di Pietro, Tea Romasco, Alessandro Specchiulli, Adriano Piattelli, and Bartolomeo Trentadue.
2023. "Finite Element Analysis (FEA) for the Evaluation of Retention in a Conometric Connection for Implant and Prosthesis" *Osteology* 3, no. 4: 140-156.
https://doi.org/10.3390/osteology3040015