Dr. Tihomir Dovramadjiev - presentation 09.06.2016 Nove Hrady - USBinCB and TUV DESIGNING...

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).


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).


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.


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)


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


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)


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)


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.



Fig. 16. High quality 3D Solid model of dental implant, abutment, tooth and part of jawbone.



Fig. 17. High quality 3D Solid model of dental implant, abutment, tooth and part of jawbone; drawing and positions



Fig. 18. Configuration of static simulation: parts, connections and contact set, fixtures, external loads (700N), mesh.

Static Study.



Results.von Mises Stress Criterion:

Table 8. Results of: Stress, Displesment and Strain



(a)

(b)

(c) Fig. 19. Results of FOS (a) Stress; (b) Displasment; (c) Strein



Fig. 20. Results of FOS. Probes of jawbone



Fig. 21. Results of FOS. Probes of implant



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



Fig. 23. Technical drawing of dental implants


IMPLANTS + GOLDEN LAYER 37

Fig. 24. Drawing of gold layer; images of dental implants; weight, volume, surface.



Fig. 25. Configuration of parameters



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)



Fig. 27. Configuration of parameters

Results of fatigue studies (external loads 300N)



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


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


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!

Liiterature[1]. Параскевич В.Л., Дентална Имплантология, Основи на теорията и практиката, 2002.[2]. Robustova T.G., Tooth implantation (surgical aspects): Guidelines for Practitioners. – M.:Medicina. ISBN 5-225-04712-2. Russia, 2003.[3]. Philip Worthington, Brien R. Lang, William E. Lavelle. Osseointegration in Dentistry.Quintessence Publishing. USA, 1969.[4]. Brånemark, Per-Ingvar; Zarb, George A.; Albrektsson, Tomas. Tissue-Integrated Prostheses:Osseointegration in Clinical Dentistry. Quintessence Publishing Company, Incorporated. ISBN: 0-86715-129-3. 1992.[5]. Asbjorn Jokstad, DDS, PhD. Osseointegration and Dental Implants. Wiley-Blackwell; A JohnWiley & Sons, Inc., Publication. USA, 2008.[6]. John A. Hobkirk, Roger M. Watson, Loyd J. Searson. Introducing dental implants. ChurchillLivingstone. ISBN 5-98322-280-5. Canada, 2007.[7]. Carl E. Misch, Contemporary Implant Dentistry, Mosby Inc.USA, 1993.[8]. Jan Lindhe, Niklaus P. Lang, Thorkild Karring. Clinical Periodontology and Implant Dentistry/fifth edition/. Blackwell Munksgaard. ISBN: 978-1-4051-6099-5. UK, 2008.

[9]. Jan Lindhe, Thorkild Karring . Niklaus P. Lang. Clinical Periodontology and Implant Dentistry

/fourth edition/. Blackwell Munksgaard. ISBN 1-4051-0236-5. UK, 2003.[10]. Nancy Arbree, DDS, M.S., History of Dental Implants. Tufts University. USA 2007.[11]. Michael R. Norton, The history of dental implants, US Dentistry 2006.[12]. R. Rudy, P. Levi, F. Bonacci, A. Weisgold, D. Engler-Hamm. Literature Review “Intraosseousanchorage of dental prostheses. An Early 20th Century Contribution”. AEGIS Communications. USAApril 2008.[13]. Michael Sonick DMD. Implant Dentistry: Evolution and Current Trends — The Times They areA-Changin’. Inside dentistry. USA October 2006.[14]. Nabil Barakat, Roger Bassit. Implant Dentistry. History and Evolution. Dept. of OMFS,Lebanese University. Lebanon, March. 2010.[15]. Mark Haswell. Dental implants: A different perspective. Implant practice US Feb.2009.

[16]. Tomas Albrektsson, Ann Wennerberg. The Impact of Oral Implants — Past and Future, 1966–

2042. Department of Biomaterials, University of Göteborg, Sweden 2005.[17]. Maarit A.M. Salonen, Kyösti Oikarinen, Kauko Virtanen, Hannu Pernu. Failures in theosseointegration of Endosseous implants. University of Oulu Implants. Finland, 1993.

....................................................................................................................................................+ 200

Dr. Tihomir Dovramadjiev - presentation 09.06.2016 Nove Hrady - USBinCB and TUV DESIGNING...

Documents

Transcript of Dr. Tihomir Dovramadjiev - presentation 09.06.2016 Nove Hrady - USBinCB and TUV DESIGNING...