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DESIGNING OSSEOINTEGRATED DENTAL IMPLANTS
University of South Bohemia in České BudějoviceNove Hrady 09.06.2016
presented by Dr. Eng. Tihomir DovramadjievAssist. Prof. At Technical University of Varna
Mechanical Technologies FacultyIndustrial Design Department
SUMMARY 1/3
Due to various reasons sometimes removal of a tooth or teeth is inevitable. It is strongly recommended the missing tooth in the row to be recovered. Otherwise, the mechanisms of functional pathology unlock. The adjacent teeth decline towards the missing place in the tooth row, and the tooth from the opposite jaw sprouts (the Godon phenomenon; Fig. 1) and so in the course of time the recovery of the resulting defect gets more and more complicated.
Fig.1. The Godon phenomenon: (a) a missing tooth in the lower jawbone; (b) in the upper jawbone
(a) (b)
SUMMARY 2/3
Restoration of the tooth row can be obtained by grinding the adjacent teeth in order to make a bridge (if the clinical picture allows it). The disadvantages are that it affects the adjacent teeth, which is not recommended, especially if they are alive. So a modern solution to the prroblem is implanting biocompatible dental implants (Fig. 2).
Fig.2. Designing variations of dental implants: (a) components: implant, abutments, screws; (b) assembly + crown
(a) (b)
SUMMARY 3/3
They retain the integrity of the facial structures and their forms, and they protect the bone from resorption. The process of implementation of dentl implants in the bone is called osseointegration (Fig. 3). It is an unique pocess in its essence and is a biochemical interaction of biocompatible titanium metal and organic bone. To enable osseointegration dental implants must have good design of the structure and bioactive suitable textured surface.
Fig.3. Osseointegration: (a) Founded by Prof. Branemark – 1951; (b) process of osseointegration
(a) (b)
METHODOLOGICAL SYSTEM 1/6
The creation of the design of dental implants is trough a construction of a stage in correct order, allowing the use of appropriate methods, materials and technological means. In order to realize this, we must take into account the various factors that affect the implant (Fig. 4).
Fig.4. Factors affecting the implant
Micro gap through Intraosteal part of the implant and abutment
Bacterial penetrationbetween the implant and
abutment
Anti-rotation and rotational movement affecting during treatment.
Micro-movement between the abutment and the implant neck
Stress on the implant during chewingmovements
METHODOLOGICAL SYSTEM 2a/6
The created stages optimize the process of designing dental implants and are systematically classified.
SELECTION OF IMPLANTATION BIOCOMPATIBLE MATERIALS
BIOACTIVE MATERIALS BIO-INERT MATERIALS BIO-TOLERANT MATERIALS
HydroxylapatiteCa 10 (PO 4 ) 6 (OH) 2
Provides adhesion of proteins and
cells of the bone tissue. Actively involved in ion exchange andmetabolism of bone matrix.
Supports ion connections withminerals of bone; - Calcium (20, Ca);
- Bioglass (is a commercially available family of bioactive glasses, composed of SiO2,
Na2O, CaO and P2O5 in specific proportions).
Ttanium (22, Ti). Titanium and its alloys (Ti-6Al-4V)
are considered as some of the most biocompatible materials that
are widely used inimplantology. In this case the interactions between medical implants and their biological
surroundings are of great importance to ensure a proper osseointegration. The latter is
relatively long, mostly dependent on the surface characteristics;
- Zirconium (40, Zr);- Gold (79, Au).
Polymethyl methacrylate and cobalt chrome (Co Cr) alloy.
Bio-tolerant materials don't have osseointegrated properties. They
do not make physico-chemical bond between the implant surface
and the bone matrix, which is necessary for formation of a connective capsule around
implant.
Table 1. Stage 1. Selection of implantation biocompatible materials
METHODOLOGICAL SYSTEM 2b/6
SELECTION BY SURFACE OF THE IMPLANT(MAIN TYPES)
SMOOTH SURFACE TEXTURED SURFACE WITH BIOACTIVE COATING
Fig.5. Variations of produced implants
Table 2. Stage 2. Selection by surface of the implant (Main types)
METHODOLOGICAL SYSTEM 2c/6
The structure of pure titanium implant after plastic deformation is shown on fig. 6
Fig.6. The structure of pure titaniuma) A screw implant made by plastic deformation (in white rectangle showing
the location of the microphotograph); (b) microstructure of the sample (x250) - thickened structure on the surface of titanium.
(a) (b)
METHODOLOGICAL SYSTEM 2d/6
At this stage, researchings show that for optimum osteogenesis and mineralization the bone tissue must be with a pore size of 70 to
700 μm. On Fig.7 is shown a sprout tissue into the pores of intraosteal of titanium implant separating from lower-jaw bone of a dog after two months.
Fig.7. Sprout tissue into the pores of intraosteal part-titanium
implant, separated from lower-jawbone of a dog after
two months
METHODOLOGICAL SYSTEM 2f/6
Fig.8. Surfaces treated by various technological processes:a) after milling; b) after electro-chemical polishing; c) treated with dust
aluminum oxide ceramic; d) after double treatment with acid.
Types of surfaces treated by various technological processes are shown on fig. 8
(a) (b) (c) (d)
METHODOLOGICAL SYSTEM 2g/6
Textured implant surfaces have been shown on Fig. 9 (scanning electron microscopy x1000).
(a) (b) (c) (d)
Fig.9. Textured implant surfaces.a) mechanical polishing sandblasting process; b) alumina ceramicparticles; c) plasma encrusted titanium; d) treatment with an acid.
METHODOLOGICAL SYSTEM 3a/6
ENGINEERING CONCEPT AND DESIGN. CAD/CAE SYSTEMSENGINEERING CONCEPT AND DESIGN OF DENTAL IMPLANTS.COMPUTING DESIGN IN SOLIDWORKS
CAD SYSTEM.
SIMULATIONS OF PHYSICAL PROCESSES AND COMPUTER ANALYSIS BY FEM (FINITE ELEMENT
METHOD FEM; FEA), USING CAE MODULECOSMOSWORKS / SIMULATION
DESIGN OF:-Part;
- Assembly;- Drawing.
Incl.: - Sustainable Design;
- PDB (Product data management)
ANALYSIS TYPES: - Stress, Displacement &Strain (FOS; Design Inside); - Thermal Stress; - Contact analysis in assemblies with friction; - Frequency & Buckling; - Heat Transfer - Steady State & Transient; - Temperature Dependent Materials; - Drop Test; - Fatigue; - Linear and Nonlinear Stress Analysis; - Dynamic Response; - Composites; - Optimization; - Fluid Flow; - Motion Simulation; - Electromagnetics.
Table 3. Stage 3. Engineering concept and design
METHODOLOGICAL SYSTEM 3b1/6
Table 4. Performance of industrial embedded product SolidWorks CAD System
INDUSTRIAL DEPLOYMENT OF SOLIDWORKS PERFORMANCE
ASSIGNMENT RESULTS ABBREVIATION TERMS OF DESIGN
REDUCTION OF LOSSES IN PRODUCTION
Design, planning andmodification of the structure
of models
Fast associative amendment
models, technologicaldrafting and drawings
More than 10 periods 2 – 3 periods
Creating design ofdocumentation and
interactiveelectronic technical
guides
Improving the quality ofdocumentation
3 – 5 periods -
Working with multiple collected
components
Increases productivityof working
5 – 10 periods -
Analysis of strength and kinematics
Abbreviation quantity ofreal trials and decreasingthe values of the prepared
test models
10 periods 2 – 3 periods
METHODOLOGICAL SYSTEM 3b2/6
Table 4 (cont). Performance of industrial embedded product SolidWorks CAD System
INDUSTRIAL DEPLOYMENT OF SOLIDWORKS PERFORMANCE
ASSIGNMENT RESULTS ABBREVIATION TERMS OF DESIGN
REDUCTION OF LOSSES IN PRODUCTION
Evaluation of dynamiceligibility analysis of the
linksand optimization of the
dimensions
Secures a 100%collecting device
3 – 4 periods 70%
Development of models with complex
form of CNC machines
Operational transmissionof models for creating
control programs for CNC
- 80%
Central data managementelectronic document
Introduced technologyrelated design,
providing operationalcheck it excludesduplication of data
More than 3 periods 40%
METHODOLOGICAL SYSTEM 3c/6
Fig.10. Interface of 3D SolidWorks CAD system
METHODOLOGICAL SYSTEM 3d1/6
Fig. 11. SolidWorks CosmosWorks / Simulation CAE system capabilities
Analysis by using FEM is called Finite Element Analysis (FEA).
METHODOLOGICAL SYSTEM 3d2/6
Fig. 12. Images of definitions, options, values and parameters (some of the needed)
Any study (FEA Analisys) in the working environment of SolidWorks, through module Simulation Premium starts with the command "Study" and adds definitions, options, values and parameters (Fig. 12).
METHODOLOGICAL SYSTEM 3d3/6
Fig. 13. SolidWorks Material Base
On fig.13 there is displayed a part of the database of multiple materials enshrined in their composition including titanium, Ti - 6Al - 4V, other titanium alloys and gold.
METHODOLOGICAL SYSTEM 3d4/6
CAE COSMOSWorks/Simulation formulates the equations governing the behavior of each element taking into consideration its connectivity to other elements. These equations relate the response to known material properties, restraints, and loads.
(a) (b)
Fig. 14. Mesh: (a) elements and nodes; (b) mesh parameters (quality)
METHODOLOGICAL SYSTEM 3d5/6
Results of the studied simulations. Table 5. Possible results obtained coefficients FOS (Factor of Safety; Static
Studies) and LF (Load Factor; Fatigue Studies)
COEFICIENT /FACTOR OF SAFETY
(FOS); LOAD FACTOR (LF)
INFLUENCE ONSTRENGTH
OF MATERIAL
RESULTS:
1 < FOS Not predicted Indicates that the material at that location is safe
1 < LF Not predicted The applied loads are less than the estimated critical loads
0 < FOS < 1 Predicted Indicates that the material at that location has failed
0 < LF < 1 Predicted The applied loads exceed the estimated critical loads
FOS = 1 Predicted Indicates that the material at that location has just started to fail
LF = 1 Predicted The applied loads are exactly equal to the estimated critical loads
METHODOLOGICAL SYSTEM 4/6
Dental internal bone implants, repetitive tooth shape are cylindrical and screwed.
Table 6. Stage 4. Selection design form of internal dental implant
SELECTION BY DESIGN FORM OF INTERNAL BONE PART OF THE DENTAL IMPLANT
DESIGN BY ROOT SHAPE OF THE TOOTH (cilyndrical)
DESIGN BY PLATE COMBINED DESIGN
Fig. 15. Design of implants (photos): (a) cilyndrical; (b) plated; (c) combined
(a) (b) (c)
METHODOLOGICAL SYSTEM 5/6
Dental internal bone implants, repetitive tooth shape are cylindrical and screwed.
Table 7. Stage 5. Selection by design of construction
SELECTION BY DESIGN OF CONSTRUCTION
Not demountable assembiles of dental implants
Demountable assembiles of dental implants
Fig. 16. Design of implants (photos): (a) not demountable; (b) demountable
(a) (b)
METHODOLOGICAL SYSTEM 6/6
In the process of designing and creating a structure of the dental implants it is necessary to forecast with what methodology the implants will be integrated into bone. According to the method of application the required implant is created with its relevant elements. The methods are two types of single-stage and two-stage implanting.
Table 8. Stage 6. Selection by design of construction manipulation methodology
SELECTION BY DESIGN OF CONSTRUCTION MANIPULATION METHODOLOGY
Single-stage implanting Two-stage implanting
AIM OF THE WORK
Tasks:- A study of the contact pressure on implant integrated into the bone by finite element method in SolidWorks
environment.
- Determination coefficients of safety (FOS) and load factor (LF) of Ti - 6Al – 4V and Au.
- Creating design implants that are ergonomically designed and have enough volume to adequately and biomechanically interact with bone tissue.
- A study of the plasma stratified coating of TiO2 and Ca10(PO4)6(OH)2 Ti - 6Al - 4V
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 1/10
The present study traces the impact of the contact load on the design of dental implants integrated into human bones. The study allows us to identify the areas under the strongest pressure and deformation state of its elements and components. The discretization of the model of the required maximum number of elements and knots will provide data of the security ratio (FOS) of the implant and the jaw bone bordering it.
The aim of this study is the identification and exploration of
the most loaded areas of dental implant.
The survey results will help in the regular and successful development of the dental implants design, which ensures good integration into the jawbone and implementation of the osseointegration process.
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 2/10
Fig. 16. High quality 3D Solid model of dental implant, abutment, tooth and part of jawbone.
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 4/10
Fig. 17. High quality 3D Solid model of dental implant, abutment, tooth and part of jawbone; drawing and positions
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 5/10
Fig. 18. Configuration of static simulation: parts, connections and contact set, fixtures, external loads (700N), mesh.
Static Study.
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 6/10
Results.von Mises Stress Criterion:
Table 8. Results of: Stress, Displesment and Strain
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 7/10
(a)
(b)
(c) Fig. 19. Results of FOS (a) Stress; (b) Displasment; (c) Strein
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 8/10
Fig. 20. Results of FOS. Probes of jawbone
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 9/10
Fig. 21. Results of FOS. Probes of implant
STUDY OF THE DENTAL IMPLANTDESIGN IN SOLIDWORKS ENVIRONMENT AND
DETERMINATION OF THE FACTOR OF SAFETY(FOS) 10/10
Conclusion of study
1. Outline the areas subjected to the greatest load, which is of great importance in the process of constructing the design of dental implants in initial stage.2. An improved design in the base of abatmenta and upper Intraosteal component of the screw implant is an important moment for constructing a successful implant with respect to interaction with the bone.3. The results relate solely for a direct integration screw implant in the bone and only the absolute values of titanium Ti-6Al-4V.4. Definition of appropriate technological tools for 3D modeling of castings in the SolidWorks environment is necessary in the assembly of objects and building the right relationships, which is a prerequisite for a conduct process simulation.5. The establishment of precise realistic 3D models in a virtual environment is a prerequisite for obtaining reliable information.6. The information obtained would be useful only in a preliminary design stage of the components of the implant, they do not affect 100% process integration of the implant in the bone and implants integration;7. The decision of tasks on the finite element method is very useful and convenient mean for a previously obtained information.
FATIGUE STUDY DESIGN OF DENTAL TITANIUM
IMPLANTS + GOLDEN LAYER 1/7
The aim of the studyThe design of the implant is created to provide initial stability to offset any micro-inaccuracy in making components and ability to neutralize bacterial penetration.The value of cyclic loading force is defined with medium 300N and number of cycles from one to ten million (with a total number of research 20), the interval from ~ 8,000,000 cycles of chewing movements correspond to 10 years.
Fig. 22. Mini dental implants – Ti-6Al-4V + Au
FATIGUE STUDY DESIGN OF DENTAL TITANIUM
IMPLANTS + GOLDEN LAYER 2/7
Fig. 23. Technical drawing of dental implants
FATIGUE STUDY DESIGN OF DENTAL TITANIUM
IMPLANTS + GOLDEN LAYER 37
Fig. 24. Drawing of gold layer; images of dental implants; weight, volume, surface.
FATIGUE STUDY DESIGN OF DENTAL TITANIUM
IMPLANTS + GOLDEN LAYER 4/7
Fig. 25. Configuration of parameters
FATIGUE STUDY DESIGN OF DENTAL TITANIUM
IMPLANTS + GOLDEN LAYER 5/7
Fig. 25. An SN curve
An SN curve.The Y- axis represents the alternating stress (S) and the X-axis represents the number of cycles (N). An SN curves used ASME (American society of mechanical engineers) standard.
Fig. 26. Gerber method - generally suitable for ductile materials.
The program always uses the von Mises stress to calculate the mean stress. Since von Mises is a positive quantity, the program adjust the sign of the first mean principal stress to it for the purpose of calculating the associated mean stress. (Official SW information)
FATIGUE STUDY DESIGN OF DENTAL TITANIUM
IMPLANTS + GOLDEN LAYER 6/7
Fig. 27. Configuration of parameters
Results of fatigue studies (external loads 300N)
FATIGUE STUDY DESIGN OF DENTAL TITANIUM
IMPLANTS + GOLDEN LAYER 7/7
Fig. 28. Load Factor (LF) results
FIG. 4:14 shows the values of the coefficient of load (Load Factor) at number 8000000 cyclic loads for all four versions of the implants. Annex 4 shows the documentation describing the process of cyclical studies and the results obtained)
Conclusion of study1. There have been developed embodiments of the design of dental implants.2. Certain areas are subjected to the most - heavy loads.3. There have been developed new versions of the design of dental implants with resistant qualities and which respond appropriately to normal loads ranging 200 - 400N.4. A discovery was made that the size of the dental implants are directly dependent on limits of their strength.
EMPIRICAL TREATMENT OF DENTAL IMPLANTS 1/3
Fig. 29. Microstructure of Ti-6Al-4V after gas plasma nitriding
at 18kW and 35kW for 5, 10 and 15 min
Fig. 30. The structure of the plasma powder coating
of TiO2 on Ti-6Al-4V
EMPIRICAL TREATMENT OF DENTAL IMPLANTS 2/3
Fig. 31. The structure of the plasma powder coating of TiO2 on Ti-6Al-4B after
sandblasting on the basis of Ti-6Al-4V
Fig. 32. Plasma powder coated mechanical mixture 50% TiO2 and 50% Ca
10 (PO 4) 6 (OH) 2 varhuTi-6Al-4V, after pretreatment with sandblasting and
subsequent nitriding
EMPIRICAL TREATMENT OF DENTAL IMPLANTS 3/3
Fig. 33. Dental implants with a plasma coating of TiO2 and Ca10(PO4)6(OH)2a) Dental implants with a coating of Ca10(PO4)6(OH)2 thickness 12μm;
b) Dental implants withTiO2 coating thickness of 12μm;
c) Dental implants with a coating of Ca10(PO4)6(OH)2TiO2 50% total thickness – 12μm.
(a) (b) (c)
CONCLUSION
To enable osseointegration, dental implants should have good structure design and bioactive suitable textured surface.There is a scientific – practical structure based in the present work and it includes successive stages necessary in creating the design in osseointegated dental implants. The main factors influencing this process are determined. A methodology of phased construction of designing osseointegrated dental implants has been developed. A methodology of defining conditions for advance forecasting of the properties of dental implants in a computer environment has been developed. There is a methodology of analyzing and evaluating the quality of microelements and the surface layer of titanium alloy Ti-6Al-4V which is issued in designing dental implants.There is a theoretical model developed of methodology of reducing the time of completing the process of osseointegration of dental implants. The results of this dissertation paper can be used by professionals engaged in computer engineering in the field of CAD/CAE/CAM systems, in testing the material layers, in dentistry and especially the dental implantology.
IMPLEMENTATION
This work successfully completed these science projects:
THANK YOU!
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