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5. Contents :
Historical review
Development of concept of osseointegration
Definitions
Scope of osseointegration
Fibrointegration Vs Osseointegration
Ultra structure of osseointegration
Biology of Osseointegration
Mechanism of osseointegration
• Contact osteogenesis vs distant osteogenesis
• Osteoinduction vs osteoconductionwww.indiandentalacademy.com
6. Anchorage mechanism or Bonding mechanism
• Biomechanical bonding
• Biochemical bonding
Key factors responsible for successful osseointegration
Success criteria of implants
Clinical evaluation of osseointegration
• Invasive methods
• Non invasive methods
Failure and loss of osseointegration
Conclusion
List of references www.indiandentalacademy.com
8. 500 BC – Etruscan population
600 AD – Mayan population
“First evidence of use of implants”
1700 – John hunter → “Transplantation”
Transmission
of various
diseases
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10. Consistent failures :
Inflammatory reaction
Gradual bone loss
Fibrous encapsulation
1960 – Linkow Blade vent implant
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11. “CONCEPT OF OSSEOINTEGRATION”
Dr. Per-Ingvar Branemark
Orthopaedic surgeon
Professor University of Goteburg, Sweden.
Threaded implant design made up of pure titanium.
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12. Integrated titanium fixture
1952 vital microscopic studies
(Bone marrow of rabbit fibula)
“Osseointegration”
Repair of major mandibular and tibial defects.
Optical chamber
Clinical Study
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13. Development of procedures for rehabilitation of edentulism :
Experimental study in dogs
First experimental study
Subperiosteal and Transosseous
Soft tissue
reaction
Use of titanium fixtures
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14. Two stage procedure
Evidence for osseointegration
Macroscopic level
Histological level
Radiological level
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15. Intact bone to
implant surface
Basic research 1952 to 1965 → 13-15 year extensive research
1965 → First clinical evidence of implant insertion
“Edentulous human patient for resorbed edentulous ridge”
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16. Definitions :
“The apparent direct attachment or connection of osseous tissue to
an inert, alloplastic material without intervening connective tissue”.
- GPT 8
Structurally oriented definition :
“Direct structural and functional connection between the ordered,
living bone and the surface of a load carrying implants”.
- Branemarks and associates (1977)
Histologically :
Direct anchorage of an implant by the formation of bone directly
on the surface of an implant without any intervening layer of
fibrous tissue.
- Albrektson and Johnson (2001)www.indiandentalacademy.com
17. Clinically :
• Ankylosis of the implant bone interface.
Schroeder and colleagues 1976
“functional ankylosis”
• “It is a process where by clinically asymptomatic rigid fixation of
alloplastic material is achieved and maintained in bone during
functional loading”
- Zarb and T Albrektson 1991
Biomechanically oriented definition :
“Attachment resistant to shear as well as tensile forces”
- Steinmann et al (1986).
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18. Scope of osseointegration in dentistry
1) Prosthetic rehabilitation of missing teeth
Complete edentulous maxilla and mandible rehabilitation.
Single tooth replacementPartial dental loss replacement
Removable prosthesisFixed prosthesis
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19. 2) Anchorage for the maxillofacial prosthesis
Auricular Prosthesis
Ocular Prosthesis
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20. 3) For rehabilitation of congenital and developmental defects
- Cleft palate
- Ectodermal
dysplasia
Nasal prosthesis
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21. 4) Complex maxillofacial defect rehabilitation
6) Orthodontic anchorage.
5) Distraction osteogenesis → new bone formation
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22. AAID (1986) – “Defined fibrous integration as tissue to
implant contact with interposition of healthy dense
collagenous tissue between the implant and bone”.
“Direct bone to implant interface without any intervening
layer of fibrous tissue”.
FIBROINTEGRATION
Vs
Concept of Bony
Anchorage
Branemark (1969)
Concept of soft tissue
anchorage
Linkow (1970), James (1975),
Weiss (1986).
OSSEOINTEGRATION
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23. Fibrosseousintegration :
“Pseudoligament”, “Periimplant ligament”, “Periimplant membrane”.
Hypothesis – Collagen fibers function similar to the sharpeys fibers in
the natural dentition.
Fact : The histological difference between the sharpeys fibers and
collagen fibers around the implant.
Natural teeth Implant
Oblique and horizontal
group of fibers
Parallel, irregular,
complete
encapsulation
Uniform distribution of
load (Shock absorber)
Difficult to transmit
the load
Failure : Inability to carry adequate loads
Infection www.indiandentalacademy.com
28. Mechanism of osseointegration
Phase Timing Specific occurrence
1. Inflammatory
phase
Day 1-10 Adsorption of plasma proteins
Platelet aggregation and activation
Clotting cascade activation
Cytokine release
Nonspecific cellular inflammatory response
Specific cellular inflmmatory response
Macrophage mediated inflammation.
2. Proliferative
phase
Day 3-42 Neovascularization
Differentiation, Proliferation and activation
of cells.
Production of immature connective tissue
matrix.
3. Maturation
phase
After
day 28
Remodeling of the immature bone matrix
with coupled resorption and deposition of
bone.
Bone remodeling in response to implant
loading
Physiological bone recession.www.indiandentalacademy.com
29. Contact osteogenesis vs distant osteogenesis :
Osborn and Newesley (1980) : Proposed 2 different phenomena
Distant osteogenesis
Contact osteogenesis
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30. Contact Osteogenesis
Relies on Migration of
Differentiating Osteogenic cell
to Implant surface
Undifferentiated
Perivascular connective cells
Differentiating Osteogenic cells
Osteoconduction :
Migration of differentiating osteogenic cells from the
recipient host bed to implant surface where they attach
and proliferate.
Fibrin
Smooth surface Rough surfacewww.indiandentalacademy.com
31. Osteoinduction :
Phenotypic conversion of undifferentiated mesenchymal cell
→osteoprogenitor cell → Bone forming cell (Osteoblast &
osteocyte)
Albrektsson and Johanson (2001) : The term osteoconduction and
osteoinduction are inter related but not the identical phenomena
that occurs during wound healing.
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32. Key factors responsible for
successful osseointegration
Implant material
biocompatibility
Loading
conditions
Implant design
characteristic
Implant surface
characteristic
State of the implantation or
host bed
Surgical
considerations
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34. Implant materials
Metals Ceramics Polymers
Chemical composition
Biological compatibility
Bio inertBio tolerant Bio active
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36. Metals :
Commercially pure titanium (CPTi) : 99.75%
Most biocompatible material → excellent long term clinical function
Adherent, self repairable
titanium dioxide (TiO2/
TiO) passivated layer.
(10A0
within seconds,
100A0
within a minute.)
Steinman (1988) referred this layer as Biologically inert
On Histological investigation → intimate contact between
the titanium surface and the periimplant bone.
(Branemark 1977, Albrektsson et al 1984)
Chemical purity, surface cleanliness → Osseointegrationwww.indiandentalacademy.com
37. Titanium alloys : Ti6Al4V(90%Ti, 6% Al, 4% V)
Johonson (1992) - Cp titanium higher torque removal values than
Ti6Al4V screw 23 vs 16N/cm.
- Higher bony contacts 59 vs 50% after 3 months
implant insertion
Experimental investigation at 3, 6 and 12th
month
Significantly stronger bone reaction to Cp
Retarded bone formation around the Ti6Al4V→ leaked out Al
ion competing with calcium during early stage of calcification
causing osteomalacia
Tantalum and Niobium : High degree of osseointegration
There was evidence of exaggerated macrophage reaction compared
to Cp titanium. www.indiandentalacademy.com
38. CERAMICS
(Calciumphosphate hydroxyapatite, Al2O3, Tricalcium phosphate)
• Makeup the entire implant
• Applied in the form of coating
Hydroxyapatite coated implant
• Gottlander 1994 – short term and longterm reaction
Short term reaction – Positive, enhanced interfacial bone formation
Long term reaction – Cp titanium 50-70% more interfacial bone
compared to HA coated.
• Hahn J (1997) HA coated implant – 97.8%(6 yrs) clinical success.
Matter of concern.Matter of concern.
HA coating loosening – macrophage activation and bone resorption
• Beisbrock + Edgertson – Microbial adhesion, Osseousbreakdown,
coating failure. www.indiandentalacademy.com
39. POLYMERS
Not used
•Inferior mechanical properties
•Lack of adhesion to living tissues
•Adverse immunological reaction
Limited to
•Shock absorbing components – supra structure component
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41. Implant Design characteristic :
Implant design refers to the three dimensional structure of the
implant.
Form, shape, configuration, geometry, surface macro structure,
macro irregularities.
Cylindrical Screw shaped implants.
Threaded Non threaded.
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42. “Precision fit in the vital bone” →Osseointegration
Cylindrical implants / press fit implants :
Severe bone resorption
Lack of bone steady state – micro movements
Alberktsson 1993 – continuing bone saucerization of 1mm -first
year, 0.5mm anually and thereafter increasing rate of resorption
upto 5 year followup.
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43. Threaded implants :
Documentation for long term clinical
function.
Alteration in the design, size and pitch of
the threads can influence the long term
osseointegration.
Advantages of threaded implants
More functional area for stress load
distribution than the cylindrical implants.
Threads improves the primary implant
stability avoids micromovement of the
implants till osseointegration is achieved.
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44. Non threaded
•Tendency for slippage
•Bonding is required
•No slippage tendency
•No bonding is required
Threaded
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47. Orientation of irregularities on the surface
Degree of roughness of the surface
Orientation of irregularities may give :
-Isotopic surface and anisotropic surface
Wennerberg (1996) Ivanoff (2001) : Better bone fixation
(osseointegration) will be achieved with implants with an
enlarged isotropic surface as compared to implant with turned
anisotropic surface structure.
Surface topography
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48. 1) Turned surface/ machined surface
2) Acid etch surface - HCl and H2SO4
3) Blasted surface – TiO2 / Al2O3 particles
4) Blasted + Acidetch surface (SLA surface)
- Al2O3 particles & HCl and H2SO4
- Tricalcium phosphate & HF & NO3
Different machining process results in different surface topographies
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51. Machined / turned surfaces : gold standard.
Moderately rough implant surfaces
• Roughness parameter (Sa)
0.04 –0.4 µm - smooth
0.5 – 1.0 µm – minimally rough
1.0 –2.0 µm – moderately rough
> 2.0 µm – rough
• Wennerberg (1996) – moderately rough implants developed the best
bone fixation as described by peak removal torque and bone to
implant contact.
• In vivo studies
Smooth surface < 0.2 µm will – soft tissue →no bone cell adhesion
→ clinical failure.
Moderately rough surface more bone in contact with implant →
better osseointegration.
: For faster & firmer bone integration
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52. Carlsson et al 1988, Gotfredsen (2000) – positive correlation
between increasing surface roughness and degree of implant
incorporation (osseointegration).
Advantages of moderately rough surface :
Faster osseointegration, retention of the fibrin clot,
osteoconductive scaffold, osteoprogenator cell migration.
Increase rate and extent of bone accumulation → contact
osteogenesis
Increased surface area renders greater osteoblastic proliferation,
differentiation of surface adherent cells.
Increased cell attachment growth and differentiation.
Increased rough surfaces :
Increased risk of periimplantitis
Increased risk of ionic leakage / corrosion
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53. Machined / turned surface
SEM x 1000 SEM x 4700
Cp Titanium
Surface roughness profile 5 µm
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54. Titanium plasma sprayed coating (TPS)
The first rough titanium
surface introduced
Coated with titanium powder
particles in the form of
titanium hydridePlasma flame spraying technique
6-10 times increase
surface area. Steinemann
1988, Tetsch 1991
Roughness Depth profile of about 15µm
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55. Hydroxyapatite coatings
HA coated implant bioactive
surface structure – more rapid
osseous healing comparison
with smooth surface implant.
↓
Increased initial stability
Can be Indicated
- Greater bone to implant
contact area
- Type IV bone
- Fresh extraction sites
- Newly grafted sites
SEM 100X
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56. Sand blasting Acid etch
The objective
Sand blasting – surface roughness
(substractive method)
Acid etching – cleaning
SEM 1000X SEM 7000X
Lima YG et al (2000), Orsini Z et al (2000).
- Acid etching with NaOH, Aq. Nitric acid,
hydrofluoric acid.
Decrease in contact angle by 100
– better
cell attachment.
Acid etching with 1% HF and 30% NO3
after sand blasting – increase in
osseointegration by removal of aluminium
particles (cleaning).
Wennerberg et al 1996. superior bone fixation and bone adaptation
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57. Laser induced surface roughening
Eximer laser – “Used to create roughness”
Regularly oriented surface roughness configuration compared
to TPS coating and sandblasting
SEM x 300
SEM x 300SEM x 70
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58. Physical characteristic :
•Physical characteristic refers to the factors such as surface
energy and charge.
Hypothesis : A surface with high energy →high affinity for
adsorption → show stronger osseointegration.
Baier RE (1986) – Glow discharge (plasma cleaning) results in
high surface energy as well as the implant sterilization, being
conductive to tissue integration.
Charge affects the hydrophilic and hydrophobic characteristic of
the surface.
A hydrophilic / easily wettable implant surface : Increases a
initial phase of wound healing.
Fact : Increase surface energy would disappear immediately
after implant placement.www.indiandentalacademy.com
59. Implant surface chemistry :
• Chemical alteration → increases bioactivity → increase implant
bone anchorage.
Chemical surfaces :
• Ceramic coated – hydroxyapatite (HA), Calcium phosphate
• Oxidized/anodized surfaces with electrolytes containing
phosphorous, sulfur, calcium, magnesium and flouride.
• Alkali + Heat treatment.
• Ionization, implantation of calcium ion, floride ions
• Doped surfaces with the BONE stimulating factors / growth
factors.
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60. Anchorage Mechanism or Bonding Mechanism in
Osseointegrated implants :
Biomechanical bonding
In growth of bone into small surface
irregularities of implant surface → three
dimensional stabilization
Seen in :
• Machined / turned screw implant
• Blasted /Acid etch surface → moderately
rough implant surface.
Based on :
• Design characteristic → Macrostructure
(Threads, vent, slots)
• Surface characteristic → Microstructure.
(Chemical surface treatmentwww.indiandentalacademy.com
61. Surface roughness at the micrometer level / nanometer level
Requirement :
Minimum size of
•50-100µm cavities or pores
→ complete bone tissue
(ground substance + cellular
components + Haversion
system)
• 1-10µm for calcified bone
ground substance.
? At nanometer level - no experimental evidence
Some investigators – nanometer size rough surface can carry proper
load. www.indiandentalacademy.com
62. Biochemical bonding
Seen with certain bioactive implant
surfaces like :
• Calcium phosphate coated implant surfaces
• HA coated implant surfaces
• Oxidized/ anodized surfaces
Bone bonding / Bonding osteogenesis
Biointegration :
•“Strong chemical bond may develop between the host bone
and bioactive implant surfaces and such implants are said to be
biointegrated”.
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63. Doped surfaces that contain various types of bone growth factors or
other bone-stimulating agents may prove advantageous in
compromised bone beds. However, at present clinical documentation
of the efficacy of such surfaces is lacking : BMP = Bone
morphogenetic protein.
Doped surfaces
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64. BONE FACTOR
• Bone quality → bone with well
formed cortex and densely
trabaculated medullary spaces
• Bone quantity → Refers to the
dimension of available bone in
reference to length, width and
depth.
Initial implant stability
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65. •Factors compromising the bone quality
Infection ,Irradiation &Heavy smoking
Branemark system (5 year documentation)
Mandible – 95% success
Maxilla – 85-90% success
Aden et al (1981) – 10% greater success rate in anterior
mandible compared to anterior maxilla.
Schnitman et al (1988) – lower success rate in posterior mandible
compared to anterior mandible
- posterior maxilla higher failure rates.
Difference in bone
composition
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66. LIKHOM AND ZARB CLASSIFICATION 1985
Class I : Jaw
consist almost
exclusively of
homogeneous
compact bone
Class II :
Thick compact
bone surrounds
highly
trabecular core
Class III :
Thin cortical
bone surrounds
highly
trabecular core
Class IV :
Thin cortical
bone surrounds
loose, spongy
core
D1 D2 D3 D4
MISCH CLASSIFICATION 1988
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67. According to Branemark and Misch
D1 and D2 bone → initial stability / better osseointegration
D3 and D4 → poor prognosis
D1 bone – least risk
D4 bone - most at risk
Jaffin and Berman (1991) – 44% failure in type IV bone
Selection of implant
D1 and D2 – conventional threaded implants
Loss of
osseointegration
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68. Osteopromotion :
Procedure to enhance the formation of bone approximating
the implant surface :
• Bone regeneration techniques (using PTFE membrane)
• Bone growth factors like PDGF, IGF, PRP, TGF-B1 →
stimulates osteoprogenitar cells, enhance the bone growth.
• Stefini CM et al (2000) recommend to apply PDGF and IGF
on the implant surfaces before placing into cervical bed. This
method showed better wound healing and rapid
osseointegration.
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69. Indications :
1) Localised ridge augmentation prior to implant placement
2) Treatment of periimplant bone defect.
Exposed implant
surface
PTFE membrane Regeneration of bone
Increased bone to implant contactwww.indiandentalacademy.com
70. Implantation bed / host bed
•Objective → Healthy implant host site
•Nature of the host site - vascularity
- cellularity (osteogenic potential)
Two Factors
•Patient Considerations - Age
•History of proposed host bed – Previous irradiation
- Infection
- History of smoking
- Advanced ridge resorption
- Osteoporosis or osteoporotic like
bone lesionwww.indiandentalacademy.com
71. Age :
Old age – no poorer result
Extreme young age - Relative contraindication to insertion of
implants.
Infrapositioning of implant because of alveolar growth
Wait till the completion of growth
Maxillofacial deformities : implant placement is delayed until
the child is at puberty.
Only in selected cases
ex: Ectodermal dysplasia
Anterior part of the jaw + over denture therapy.
Bone anchored
hearing aids :
2-3 year old child.
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72. Smoking and osseointegration :
• History of smoking may affects the healing response in
osseointegration.
• Lower success rates with oral implants
• Mechanism behind
Vasoconstriction
Reduced bone density
Impaired cellular function
• Mean failure rates in smoker is about twice than in non smoker.www.indiandentalacademy.com
73. Radiation therapy and osseointegration :
• Jacobsson (1985) previous irradiation – relative contraindication
for implant placement.
• Expected success rate 10-15% lower than the non irrradiated
patients.
Number of factors to be considered :
• Dose and fraction of irradiation
• Timing from radiotherapy to implant surgery
• Anatomic region in which the implant to be inserted
• Loading factors and handling of the soft tissue.
Full course radiotherapy (50-65Gy) → Not contraindicated.
> 65 Gy → critical for implant survival.
• Johnson (1987) Surgical risk → 1m before and 6m after,
Low risk → 6m to 1.5 yr
Increased risk → there after.
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74. Hyperbaric oxygen therapy (HBO) :
• HBO → Elevates the partial pressure of oxygen in the tissues.
• Granstrom G (1998) → HBO can counteract some of the
negative effect from irradiation and act as a stimulator for
osseointegration.
• Role of HBO in osseointegration
– Bone cell metabolism
- Bone turnover
- Implant interface and the capillary
network in the implant bed
(angiogenesis)
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79. Critical temperature for bone necrosis
• Previously 560
to 700
for 1 min.
• 560
C critical temperature for bone necrosis → Irreversible bone
damage.
• Recently 470
C for 1 min.
Denaturation of alkaline phosphate enzyme → inhibition of
Alkaline Ca synthesis → Loss osseointegration (Errickson 1986,
Albrektsson 1984) www.indiandentalacademy.com
80. Insertion torque
Insertion torque is high – removal torque is low.
Poor osseointegration
High torque is used → stress / compression in bone
Holding power of implant will fall.
45 N/cm
Moderate torque should be used
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82. Loading condition
Objective : “No loading while healing” → successful
osseointegration.
Movement of the implant within the bone – fibrous tissue
encapsulation rather than osseointegration.
Premature loading
leads to implant
movement
The end result
“Soft tissue
interface”
“Bony interface”
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83. Branemark, Albrektson – two stage implant insertion.
First stage – Installation of fixture into bone
Second stage – Connection of abutment to the fixtures
Maxilla 6 months
Mandible 3 months
Misch – Progressive / Gradual loading
Different Philosophies regarding Loading conditions
Suggested in
Softer bone
less number of implants to be used
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84. Immediate functional loading protocol
Clinical trials successful osseointegration
(95-100% success rate- Completely edentulous patients)
Bone quality is good
Functional forces are controlled
More favourable in mandible compared to maxilla
Over loading – Stress concentration, undermining bone
resorption without apposition (Branemark 1984)
To decrease the bio mechanical load
Prosthetic design considerations
Cantilever length may be shortened or eliminated
Narrow occlusal table
Minimizing the offset load
Increasing the implant number
Use of wider implant with D4 bone compared to D1 & D2www.indiandentalacademy.com
85. Success criteria of implants :
Schuitman and Schulman criteria (1979)
1) The mobility of the implant must be less than 1mm when
tested clinically.
2) There must be no evidence of radiolucency
3) Bone loss should be less than 1/3rd
of the height of the
implant
4) There should be an absence of infection, damage to structure
or violation of body cavity, inflammation present must be
amneable to treatment.
5) The success rate must be 75% or more after 5 years of
functional service.
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86. Albrektson and Zarb G (1980)
1) The individual unattached implant should be immobile when
tested clinically
2) The radiographic evaluation should not show any peri-implant
radiolucency
3) Vertical bone loss around the fixtures should be less than
0.2mm annually after first year of implant loading.
4) The implant should not show any sign and symptom of pain,
infection, neuropathies, parastehsia, violation of mandibular
canal and sinus drainage.
5) Success rate of 85% at the end of 5 year observation period and
80% at the end of 10 year service.
Smith and Zarb (1989)
6) Implant design allow the restoration satisfactory to patient and
dentist. www.indiandentalacademy.com
87. METHODS OF EVALUATION OF OSSEOINTEGRATION
Invasive method
•Histological section
•By using torque gauges
•TEM (transmission electron microscopy)
•Pullout test
•Histomorphometric
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91. List of References :
Osseointegration in clinical dentistry – Branemark, Zarb, Albrektsson
Osseointegration and occlusal rehabilitation – Sumiya Hobo
Contemporary Implant Dentistry – Carl. Misch
Endosseous implants for Maxillofacial reconstruction – Block and Kent
Implants in Dentistry –Block and Kent
Dental and Maxillofacial Implantology – John. A. Hobkrik, Roger Watson
Endosseous Implant : Scientific and Clinical Aspects – George Watzak
Optimal Implant Positioning and Soft Tissue management – Patrik Pallaci
Osseointegration in craniofacial reconstruction. T. Albrektssson.
Osseointegration in dentistry : an introduction : Philip Worthington, Brein. R.
Lang, W.E. Lavelle.
IJOMI 2005; 20(2): 307-311
IJOMI 2005; 20: 425-31
IJP 2004; 17: 536-543.
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