osseointegration in dental implants and factors considered in it

1. OSSEO
INTEGRATION
BHUVANESH KUMAR.DV

2. CONTENTS
1. HISTORICAL BACKGROUND
2. DEFINITIONS AND TERMINOLOGIES
3. MECHANISM OF OSSEOINTEGRATION
4. FIBROOSEUS VERSUS OSSEOINTEGRATION
5. BIOINTEGRATION VERSUS OSSEOINTEGRATION
6. IMPLANT TISSUE INTERFACE
7. FACTORS EFFECTING OSSEOINTEGRATION
8. METHODS TO CHECK OSEOINTEGRATION
9. SUCCESS CRITERIA
10. COMPLICATIONS IN OSSEOINTEGRATED
IMPLANTS
11. CONCLUSION

3. Introduction
–A successful replacement of missing natural
tooth by dental implant supported prosthesis is
a major clinical advance in dental science.
–The successful outcome of the treatment
depends upon the degree of Osseointegration.
–The science of Osseointegration has evolved
over the last few decades in both
experimentally or clinically due to extensive
multidisciplinary approach.

4. –The present surge in the use of implants was
initiated by Branemark (1952)
– He described the relationship between
titanium and bone for which they coined the
term OSSEOINTEGRATION.
– The word “osseointegration” is derived from
latin words:
– “os” – meaning bone, and
– “integration” - meaning the state of being
combined into a complete whole

5. HISTORICAL
BACKGROUND

6. –The concept of Osseo integration based on
research that began by Branemark in 1952.
–He wanted to observe the microcirculation of
both soft and hard tissues under various phases
of injuries.

7. –He implanted titanium optic chamber in to
rabbits fibula and carried out the investigation
with a vital microscopic (essentially made of
titanium) and when he tried to remove the
titanium chamber he found that bone was
normally adhered to the metal.
–This led to an idea of using titanium as an implant
material in the oral cavity.

8. – However the direct bone to implant surface connection
without intervening connective tissue was described
away back in 1939 by Strock.
– Later may researchers like Schroeder et al (1976),
Alberktsson et al (1986) proposed fibrous theory of
implant fixation, Robert et al (1987), Cork et al (1987),
William (1986), Bebbush (1986), Meffert et al (1992)
and may more have dose extensive studies on retention
of dental implants.
– But it is Dr. Per Ingvar Branemark, who is considered as
the prime proponent for the philosophy that the
absence of connective tissues at bone implant interface
is the Key to clinical success in dental implantology.

9. DEFINITION
AND
TERMINOLOGIES

10. OSSEOINTEGRATION
 1969- “As a direct contact between the
bone and metallic implants without
interposed soft tissues layers”.
 1977 – “Direct structural and functional
connection between ordered, living bone
and the surface of a load carrying
implant.”

11. According to GPT-8
“ the apparent direct
attachment or connection of
osseous tissue to an inert,
alloplastic material without
intervening connective
tissue”

12. Meffert et al (1987)
ADAPTIVE OSSEOINTEGRATION
Osseous tissue approximating the surface of
the implant without apparent soft tissue
interface at light microscopic level.
BIOINTEGRATION
Is a direct biochemical bone surface
attachment confirmed at electron
microscopic level.

13. OSTEOPRESERVATION (STALLARD R.E )
Tissue integration around healed functioning
endosteal dental implant in which the prime load
bearing tissue at the interface is a periimplant
ligament composed of osteostimulatory collagen.
PERIOSTEAL INTEGRATION
Tissue integration around a healed functioning
subperiosteal implant in which the load bearing
tissue is the sheath of dense collagenous tissue
constituting the outer layer of periosteum.

14. MECHANISM
OF
OSSEOINTEGRATION

15. – The damage caused during the surgical procedure and
the interlocking of the implant to the hard and soft
tissues initiate the process of healing.
The wound healing at the implant site depends on the –
 Presence of adequate cells
 Their adequate nutrition
 Adequate stimulus for bone repair
– The three main phases of bone healing necessary for
osseointegration are –
 Phase 1 Inflammation
 Phase 2 Proliferation
 Phase3 Maturation

17. The surgical invasion of the nature bone cause vascular
trauma at the osteotomy site is instantly filled with blood
and subsequently the implant surfaces.
A series of cellular and molecular events is initiated as a
response to surgical trauma that includes
a. Injury phase (0 to 2 weeks)
b. Granulation phage (2 to 3 weeks)
c. Callus phase (4 to 16 weeks)
Thus mechanism of osseointegration can be subdivided
into three biologic phenomena as described by J.E.
Davies (1998), they are
1. Osteoconduction
2. New bone formation
3. Bone remodeling

18. Osteoconduction
• After surgical installation of the implant fixture the
surgically injured bone and implant surfaces exposed to
extra cellular fluid and non- collagenous protein.
• The migration of the osteogenic cell is attracted by
chemotaxis mechanism and this phenomena of
migration is described as ‘osteoconduction”.
The rate of osteoconduction as documented by Osborn
and Newesely (1980) is dependent on the implant surface
design i.e., if the quality of the implant surface to
withstand the detachment of the fibrin during cell
migration is more then the differentiating osteogenic
cells will be more closure to implant surface.

19. Osteogenesis (De Novo Bone formation)
J.E. Davies et al (1996) described the cascade of new
bone formation in four different stages.
Stage 1: The differentiating osteogenic cells initially
secrete collagen free organ matrix with two non-collagen
proteins osteopontin and bone sialoprotien.
Stage 2: The organic matrix provide nucleation site for
calcium phosphate mineralization. The nucleation will
be found at the calcium binding sites of one or both of the
protein of the organic matrix.

20. Stage 3: Calcium phosphate crystal growth takes place
after nucleation and concomitantly there will be initiation
of collagen fibre assembly at the developing interface.
Stage 4: Finally calcification of individual collagen fibrils
and collagen compartments take place and they are
separated by a collagen free calcified tissue layer
containing non collagen protein.
This layer is 0.5 m thick and described by Davies (1998)
as cement line which was first described by a German
histologist Von Ebner as Kittlinin or Cement
lines, 123 years ago. This is the calcified interfacial matrix
laid down between old and new bone.

21. Bone remodeling
The Stage of remodeling starts around 3rd month &
become highly active for several weeks , then slows
down again.
As proposed by Forst, remodeling take place as
discrete unit in both cortical and cancellous bone.
Remodeling starts with osteoclastic resorption
followed by lamellar bone deposition, so resorption
and deposition of bone goes side by side to maintain
the healthy skeletal mass.

22. THEORIES ON
BONE TO
IMPLANT
INTERFACE

23. There are two basic theories regarding the bone-
implant interface.
a) Fibro-osseous integration (Linkow 1970,
James 1975, and Weiss 1986)
b) Osseointegration (supported by Branemark,
Zarb, and Albrektsson 1985)

24. Fibro-osseous integration
Fibro-osseous integration refers to a presence of
connective tissue between the implant
and bone.
In 1986, the American Academy of Implants
Dentistry (AAID) defined fibrous integration as
“tissue-to-implant contact with healthy dense
collagenous tissue between the implant and
bone”

25. Weiss stated that the presence of collagen fibers
at the interface between the implant and bone is
a peri-implant membrane with an osteogenic
effect.
The difference between compression and
tension of the connective tissue components
results in a bioelectric current, and this current
(a piezoelectric effect) induces differentiation
into connective tissue components associated
with bone maintenance.

26. Failure of fibro-osseous theory
According the theory , pseudo-periimplant Fibrous membrane
gave a cushion effect and acted as similar as periodontal membrane
in natural dentition.
However, there was no real evidence to suggest that these fibers
functioned in the mode of periodontal ligament and when in function
the forces are not transmitted through the fibers as seen in natural
dentition.
Therefore, remodeling was not expected to occur in fibrous
integration.
Moreover the forces applied resulted in widening fibrous
encapsulation, inflammatory reactions, and gradual bone
resorption there by leading to failure.

27. Theory of Osseointegration
Meffert et al, (1987) redefined and subdivided
the term osseointegration into “adaptive
osseointegration” and “biointegration”.
“Adaptive osseointegration” has osseous
tissue approximating the surface of implant
without apparent soft tissue interface at the
light microscopic level.
“Biointegration” is a direct biochemical
bone surface attachment confirmed at the
electron microscopic level.

28. Unlike fibro-osseous integration, osseointegration
was able to distribute vertical and slightly inclined
loads more equally in to surrounding bone.
If osseointegration does not occur or
osseointegration is lost for some reason, a fibrous
connective tissue forms around the implant.
In such condition, the organization process
continues against the implant material, possibly
resulting from chronic inflammation and
granulation tissue formation & osseointegration will
never occur (Albrektsson et al, 1983).

29. What may be the cause for connective tissue
interface?
 Premature loading of implant system earlier than
3-6 months
 Apical migration of junctional epithelium into the
interface followed by connective tissue elements
 Placing the implant with too much of pressure
(Linkow & Wertman)
 Overheating the bone during site preparation
(>116 F)
 Implant not fitting the site exactly (Carlsson et
al)

30. OSSEOINTEGRATION VS.
BIOINTEGRATION

31. 1985 – Putter et al observed 2
ways of implant anchorage
 Mechanical
 Bioactive

32. Bioactive

Achieved with bioactive
materials such as
hydroxyapatite

Bond directly to bone

Bone matrix deposited on
HA layer due to
physiochemical interaction,
between collagen of bone
and HA crystals of implant

Plasma spraying/ ion sputter
 Two techniques use to
coat implant with HA
Mechanical

Titanium / Ti alloys

Retention based on
undercut forms such as
slots, vents, screws etc.

Direct contact between the
dioxide layer. E.g. the base
metal and bone with no
chemical bonding
Retention depends on
surface area.
Surface area contact

33. Implant Tissue
Interface

34. Implant – CT Interface
Implant – Epithelium Interface
Implant – Bone Interface

36. IMPLANT AND BONE INTERFACE
Light microscopic level (100X)

Close adaptation of the regularly organized bone next to the Ti
implants.
Scanning electron microscopic level

Parallel alignment of the lamellae of haversian system of the bone
next to the Ti implants. No connective tissue or dead space at the
interface.
Ultramicroscopic(500 to 1000X) level

Amorphous coat of glycoproteins on the implants to which the
collagen fibers are arranged at right angles and are partly
embedded into the glycoprotein layer.

37. IMPLANT CONNECTIVE TISSUE
INTERFACE
Supracrestal connective tissue fibers will be arranged parallel to the
surface of the implant
 Not as strong as that of the connective tissue and tooth interface.
 An implant has no connective tissue fibers in the connective tissue
zone that insert into the implant .

38. Implant Epithelial Interface
“Biologic seal”
Hemidesmosomes attached to glycoprotein layer

Connect the interface to the plasma membrane of
the epithelial cells

Similar to the junctional epithelium, Sulcus depth
varies from 3 to 4mm

39. FACTORS
EFFECTING
OSSEOINTEGRATION

40. Six different factors known to be important for the
establishment of a reliable, long-term osseous
anchorage of an implanted device
Implant biocompatibility
Design characteristics
Surface characteristics
State of the host bed
Surgical technique and
Loading conditions

41. Implant Biocompatibility
Response of bone to different implant material is
the principal factor on which an implant material is
selected as suitable or unsuitable for
osseointegration
 Chemical interaction determined – properties of surface
oxide
Commercially pure (c.p.) Titanium and Titanium alloy (Ti -
6AL-4V)
 Documented long term function
 Covered with adherent, self- reparing oxide layer
 Excellent resistance to corrosion – high dielectric
constant
 Load bearing capacity

42. The mechanical properties of Titanium alloy are
superior to C.P-Titanium
Other metals
 Niobium, tantalum
 Cobalt chrome molybdenum alloys
 Stainless steels
 Ceramics - calcium phosphate hydroxyapatite (HA) and
various types of aluminium oxides
Biocompatible - insufficient documentation and very less
clinical trials - less commonly used.

43. Degree of
Compatibility
Characteristics of
Reactions of Bony
Tissue
Materials
Biotolerant Implants separated from
adjacent bone by a soft
tissue layer along most
of the interface: distance
osteogenesis
Stainless steels: CoCrMo
and CoCrMoNi alloys
Bioinert Direct contact to bony
tissue contact osteogenesis
Alumina ceramics,
zirconia ceramics,
titanium, tantalum,
niobium, carbon.
Bioactive Bonding to bony tissue:
bonding osteogenesis
Calcium phosphate-
containing glasses,
glass-ceramics,
ceramics,
titanium
Grouping of hard tissue replacement materials
according to their compatibility to bony tissue

44. Implant Design (Macrostructure)
Threaded or screw design implants
 Demonstrated to function for decades without clinical
problems.
 Provide more functional area for stress distribution
than the cylindrical implants.
 Minimal - <0.2 mm/year bone loss
Cylindrical implants
 Press fit root form implants depend on coating or
surface condition to provide microscopic retention
and bonding to the bone
Combination root forms
 Macroscopic features of cylinder and screw root
forms

45. The design of the threads
The dental implant applications dictate the need for a
thread shape optimized for long term function , load
transmission under occlusal , intrusive and shear loading
Functional surface area per unit length of implant
may be modified by the three thread geometry
parameters
• Thread shape
• Thread pitch
• Thread depth

46. •Square thread
Optimized surface area for intrusive and compressive
loads
Shear force 10 times lesser than V shape
•Decreased thread pitch increases the functional
surface area surface area
•The greater the thread depth the greater the surface
area of the implant , if all factors are equal
A wider diameter ,more threads ,deeper
threads and surface structure that increase the
initial bone contact percentage are of great
benefit. Alterations in these are suggested
according to Bone density.

47. Grooves on implants
Grooves on the threads of all implants and on
the collars, wherever appropriate.
Increase surface area
Increase area for bone-to-implant contact

48. Implant Surface (Microstructure,
Surface Topography)
“The extent of bone implant interface is positively
correlated with an increasing roughness of the implant
surface” Roughened surface
 Greater bone to implant contact at histological level
 Micro irregularities - cellular adhesion.
 High surface energy - improved cellular attachment.

49. Methods
 Electroploishing
 Sand blasting
 Sand blasting and acid etching
 Titanium plasma spraying
THE TITANIUM WITH HIGHEST BONE TO
IMPLANT CONTACT WAS CREATED WITH LARGE
GRIT AND ACID ATTACK.
THIS SURFACE GAVE SIMILAR BONE TO IMPLANT
CONTACT AS DID IMPLANTS COATED WITH
HYDROXY APATITE.

50. SURFACE COATINGS
Two materials plasma sprayed onto implant body
 Titanium
 Hydroxyapatite
Advantages of TPS
 Increased surface area
 Increased roughness for initial stability
 Stronger bone to implant interface
Advantages of Hydroxyapatite on
TPS
Faster healing bone interface
Stronger interface than TPS
Less corrosion of metal

51. State of the Host Bed
Ideal host bed
Healthy and with an adequate bone stock
 BONE HEIGHT
 BONE WIDTH
 BONE LENGTH
 BONE DENSITY
Undesirable host bed states for implantation
 PREVIOUS IRRADIATION
 RIDGE HEIGHT RESORPTION
 OSTEOPOROSIS

52.  10-15% poorer clinical results must be anticipated after a
therapeutic dose of irradiation - vascular damage, at least
in part.
 Such clinical states may constitute an indication for ridge
augmentation with bone grafts.
 As stated by Branemark et al and Misch, the bones with D1
and D2 bone densities shows good initial stability and
better osseointegration.
SELECT SUITABLE IMPLANTS DEPENDING ON THE
QUALITY AND QUANTITY OF AVAILABLE BONE

53. Surgical Considerations
The main aim of the careful surgical preparation of
the implant bed is to promote regenerative type of
the bone healing rather than reparative type of the
bone healing.
The critical time/ temperature - bone tissue
necrosis - 47° for one minute.

54. Recommendations by Erickson R.A.
 Slow speed
 Graded series
 Adequate cooling
 Avoid Overheating
 Bone cutting speed of less than 2000 rpm
 Tapping at a speed of 15 rpm with irrigation
 Using sharp drills

55. The surgical preparation sequences as well as the
instruments depend upon the quality of the bone.
Number of drills used to prepare implant osteotomy
corresponds to bone density
 D1 uses six drills and D3 uses four Drills
 D4 uses osteotomes to compact fine trabecular
bone.
 Bone taps are used for D1 and D2 bone.
 Countersink drill is optional in D3 bone

56. Power used at implant insertion
 Holding power of the implant will fall to dangerous levels
after a strong insertion torque.
 A moderate power at the screwing of an implant is
therefore recommended.
 The optimal torque threshold – 35 N/cm.
 Implant should gently engage the bone in order to avoid
too much pressure at the bone interface which could
jeopardize healing

57. Surgical fit of the fixture
 The accurate fit consists of more surface contact,
less dead space and thus better healing.

58. Loading Conditions
Progressive or two stage loading
Immediate or one stage or
nonsubmerged loading

59. Progressive or two stage loading
Branemark etal to accomplish osseointegration
considered the following prerequisites
Countersinking the implant below the crestal bone
Obtaining and maintaining a soft tissue covering
over the implant for 3 to 6 months
Maintaining a nonloaded implant environment
for 3 to 6 months

60. Elements of progressive loading
Time interval
Diet
Occlusal material
Occlusal contacts
Prosthesis design

61. TIME
The healing time between the initial and second
stage surgeries for
D1 and D2 is similar – 3 to 6 months
 D3 and D4 – 5 to 6 months
3 month loading delay in the mandible and a 4-6 month
delay in the healthy maxillary bone - more
cancellous in character.

62. DIET
The dentist controls diet of the patient to prevent
overloading.
Initial healing phase- avoid chewing in the area.
Initial transitional prosthesis to final prosthesis –
soft diet
After evaluation of final prosthesis function,
occlusion and cementation - normal diet.

63. OCCLUSION
Initial healing – no occlusal contacts
No occlusal contacts on cantilevers
Final restoration - implant protective occlusion
concepts.

64. The salient features of Branemark and his team’s
work
 About more than 50 designs of Ti screws (implants) were
tested and used.
 The surgical protocol followed was: two stage surgery,
which was proved beneficial.
 Minimal trauma during the surgery results in bone
regeneration rather than bone repair at the implant site.
 Non-contaminated implants (sterile and clean implants)
prove good integration.
 Prosthesis and abutments were screw attached for more
technical flexibility.
 There were more mechanical failures at the interface
rather than biological failures.

65. IMMEDIATE LOADING
 Non submerged one stage healing
 Loads the implant with a provisional restoration at the
same appointment or shortly thereafter.
Rationale
 Reduces the risk of fibrous tissue formation
 Minimizes woven bone formation
 Promotes lamellar bone maturation to sustain occlusal
load
 Enhances bone remodeling
 Increased bone density

66. The aim of this study was the evaluation, from a
clinical point of view, of implants subjected to
immediate functional loading (IFL) and to
immediate non-functional loading (INFL) in
various anatomical configurations.
3557 Immediate Functional and Non
Functional loading of dental implants: a
clinical study of 646 titanium implants
M. DEGIDI, M. PIATTEL, G. PETRONE, and A. PIATTELLI, University
of Chieti, Italy, J PERODONTOLOGY 2003

67. Whenever esthetic , psychological or
functional conditions allow it , second stage
surgery is no longer necessary.
In totally edentulous patient- IFL - reliable.
Partially edentulous – adequate bone quality
and quantity available- INFL brings together
the advantages of IFL while reducing the
biomechanical risks to a minimum.
Careful patient selection remains , in any
case important.

68. Immediate loading versus immediate provisionilazation
of maxillary single tooth repalcements –A prospective
randomized trial with Biocomp implants
J oral maxilofacial surg 2006
No significant differences in radiographic
bone loss and gingival esthetics were found
between Immediate non loaded
provisionilazation and immediate loaded
Biocomp implants in the maxilla.

69. The Endopore dental implant incorporates a unique,
truncated cone-shaped design that uses a
multilayered porous surface geometry over most of
its length to achieve integration by three-
dimensional bone ingrowth.
Endopore dental implant

70. Endopore's surgical Advantages
 A secure, three-dimensional interlocking interface with
bone
 Predictable and minimal crestal bone remodeling
 Uncomplicated surgical sequence
 Minimal instrumentation and inventory
 Self seating , tapered, pressfit, prosthetically friendly
design
 Good resistance to torsional forces
 Shorter initial healing time.

71. Methods of Evaluation
of
Osseointegration

72. Implant stability
Stability is a requisite characteristic of
osseointegration.
When an implant is placed surgically, initial
stability is a function of the bone quality,
implant deign and surgical technique.
Implant placed in the dense cortical bone
should have higher initial stability than in a
weak cancellous bone

73. During the osseointegration healing and
maturation process , the initial stability changes
with increases in bone- to –implant contact and
osseous remodeling.
It is unknown however what precisely
constitutes “adequate stability” to warrant
proceeding with restoration.

74. Rigid fixation
Absence of observed clinical mobility.
Two terms osseointegration and rigid fixation are
interchangeably used.
A healthy implant moves less than 73microns –
appears as zero clinical mobility .
The goal for root form implants should be rigid
fixation.

76. Invasive Methods
Histological sections (10 microns sections)
Histomorphometric – To know the percentage
of bone contact
Transmission electron microscopy
By using Torque gauges

77. Non-Invasive Methods
Percussion test
Tapping with a metallic instruments
The fixture produces ringing sound- osseointegrated.
Dull sound - fibrous integration.
Radiographs
Perio-test
Checks mobility and damping system.
Normal values - 5 to +5 PTV {perio test values}
Dynamic model testing
Resonance frequency analysis
Impulse testing

78. The Success Criteria (Alberktsson et al)
The individual unattached implant should be
immobile when tested clinically.
The radiographic evaluation should not show
any evidence of radiolucency.
The vertical bone loss around the fixtures
should be less than 0.2mm per year after first
year of implant loading.

79. The implant should not show any signs of
pain, infection, neuropathies, parasthesia,
violation of mandible canals and sinus
drainage.
The success rate of 85% at the end of 5 year
and 80% at the end of 10years

80. COMPLICATIONS
IN
OSSEOINTEGRATED
IMPLANTS

81. POTENTIAL
PROSTHODONTIC COMPLICATIONS
 Improper implant placement
 Abutment screw fracture
 Framework fracture
 Esthetics
 Speech
 Gingival complications
 Peri implantitis
Successful reconstruction, however means more than
successful integration . Predetermination of the framework
design, the components to be used, and esthetic and speech
requirements will ensure a more predictable prosthodontic
reconstruction.

82. CONCLUSION

83. As the concept of osseointegration has developed and
spread globally , it has had a dramatic impact on the
practices of dentistry.
 In implant dentistry , an undisturbed healing period is
always required to ensure osseointegration.
 A modified protocol with early or immediate loading
has been tested to satisfy the demand of more rapid
treatment and to reduce discomfort of wearing
removable appliances during the healing period.
 Provided that the implant has primary stability , studies
have shown that the survival of loaded implants can be
analogous to the unloaded protocol.

84. BIBLIOGRAPHY

85. THANK YOU