implant materials

1. IMPLANT MATERIALS
DR RITESH SHIWAKOTI

2.  IMPLANT – is defined as insertion of any object
or a material , which is alloplastic in nature either
partially or completely into the body for therapeutic ,
experimental , diagnostic or prosthetic purpose .

3.  FATHER OF IMPLANT DENTISTRY:
Per Ingvar Branemark

4. Advantage of Implant
 To overcome the drawbacks of removable
prostheses
 Bone maintenance of height and width
 Ideally esthetic tooth positioning
 Improved psychological health
 Increased stability in chewing
 Increased retention
 Eliminates need to involve adjacent teeth

5. Materials used in the fabrication of the implant can be
generally classified into two different ways :
1. Chemical point – metals and ceramics
2. Biological point – biodynamic materials :
biotolerant , bioinhert , bioactive.

6. Materials regardless of use fall into four different
categories :
1. Metal and metal alloys : metals that are used in
implants are titanium , tantalum , and alloys Ti-Al-
Va , Co-Cr-Mb , Fe-Co-Ni
2. Ceramics
3. Synthetic polymers
4. Natural materials

7. Bioinhert materials allow close approximation of
bones in their surface leading to contact
osteogenesis.
These materials allow formation of new bone in their
surface and ion exchange with the tissue leads to the
formation of chemical bonding along the interface
bonding osteogenesis.

8. Biotolerant are those that are not necessarily rejected
when implanted into the living tissiue.
They are human bone morphogenetic protein-2( rh
BMP-2 ) which includes bone formation de nevo.
Biomemtic are tissue interegated engineered materials
design to mimic specific biologic processes and help
optimize the healing/regenerative response of the
host microenviroment.

9. Bioinhert and bioactive materials are also called
osteoconductive meaning that they can act as
scaffolds allowing bone growth on their surfaces.

10. Factors affecting implant biomaterials
1. Mechanical
2. Chemical
3. Electrical and
4. Surface specific properties

11. Chemical factors:
Corrosion : loss of metallic ions from the surface of the
metal to the surrounding enviroment.
 General : occurs when the metal is immersed into an
electrolyte solution.
 Pitting : occurs in an implant with a small surface pit
placed in a solution.
 Crevice : occurs in the bone-implant interface or an
implant device where an overlay or composite type
surface exist on metallic substrate in a tissue/fluid
environment with minimal surface , little or no oxygen
may be present in the crevice.

12. Surface – specific factors
Event at the bone-implant interface:
The performance of the implant can be classified in
terms of :
1. The response of the host to the implant
2. The behaviour of the material in the host

13. Material response: The event that occurs
immediately upon implantation of metals i.e. Results
in release of proteins to the blood from the wound
surface and cellular activity in the interfacial region.
Host response: Involves series of cellular and matrix
events ideally culminating in tissue healing leading
to intimate apposition of the bone to the
biomaterials i.e. Osseo integration.

14. Electrical factors
Physiochemical method:
1. Surface energy
2. Surface charge
3. Surface composition are the three factors that aim
to improve the bone implant interface.

15. Morphologic method :
Alteration in biomaterials surface morphology and
roughness have been used to influence the cells and
tissue response to the implant.
Biochemical method:
The goal is to immobilize protein, enzyme or peptide
on biomaterials for the purpose of inducing specific
cell and tissue response.

16. Mechanical properties
Properties considered are:
1. Modulus of elasticity
2. Tensile strength
3. Compressive strength
4. Elongation and
5. Metallurgy

17. Classification of implant
1. Based on implant design
2. Based on attachment mechanism
3. Based on macroscopic body design
4. Based on the surface of the implant
5. Based on the type of the material

18. Classification based on implant design:
1. Endosteal
1. Ramus frame
2. Root form
3. Blade form
2. Sub-periosteal
3. Transosteal
4. Intramucosal

19. Endosteal implant:
 A device which is placed into the alveolar bone
and/or basal bone of the mandible or maxilla
Transect only one cortical plate

20. Blade form implant:
It consist of thin plates in the form of blade embedded
into the bone

21. Ramus frame implant:
 Horse shoe shaped stainless steel device
 Inserted into the mandible from one retromolar pad
to the other
 It passes through the anterior symphysis area

22. Root form implant:
 Designed to mimic the shape of the tooth
 For directional load distribution

23. Subperiosteal implant
Placed directly beneath the periosteum overlying the
bony cortex

24. Transosteal implant
 Other names- Staple bone implant
Mandibular staple implant
Transmandibular implant
 Combines the subperiosteal and endosteal
components
 Penetrates both cortical plates

25. Intramucosal implant
 Inserted into the oral mucosa
 Mucosa is used as attachment site for the metal
inserts

26. Classification based on attachment mechanism
1. Osseointegration
2. Fibro-integration

27. Osseo integration:
 Direct contact between the bone and the surface of
the loaded implant
 Described by BRANEMARK
 Bio active material that stimulate the formation of
bone can also be used

28.  Biological considerations for
osseointegration
 Bone implant interface
 Bone remodeling
 Foreign body reaction

29.  Bone to implant interface
 Mechanism of osseointegration
 Ultrastructure in osseointegration
 Destruction of osseointegration
 Soft tissue implant interface
 Peri-implant membrane
 Disease activity in peri-implant tissue
 Neuromuscular system as it relates to the
implant

30.  Osseointegration is defined as a direct bone
anchorage to an implant body which can
provide a foundation to support a prosthesis.
 “Direct structural and functional connection between ordered, living bone and
surface of a load carrying implant”.

31.  American Academy of Implant Dentistry defined it as “contact
established without interposition of non bone tissue between
normal remodeled bone and on implant entailing a sustained
transfer and distribution of load from the implant to and within
bone tissue”.

32. Biological Considerations for
Osseointegration
 Bone implant interface
 When compared to compact bone spongy bone has
less density and hardness is not a stable base for
primary fixture fixation.
 In the mandible the spongy bone is more dense than
maxilla.
 With primary fixation in compact bone,
osseointegration in the maxilla require a longer
healing period.

33. Bone remodelling
 Osseointegration requires new bone
formation around the fixture. A process
resulting from remodeling within bone
tissue.
 Osteoblastic and osteoclastic activity helps
maintain blood calcium without change in
quantity of bone

34.  To maintain a constant level of bone
remodeling there should be proper local
stimulation, crucial levels of thyroid
hormone, calcitonin and vitamin D.
 Occlusion or occlusal force stimulus are both
important to optimal bone remodeling

35. Foreign body reaction
 Organization or an antigen antibody reaction
occurs when a foreign body is present in the
body.
 This reaction occurs in the presence of a protein
but with implant materials devoid of proteins no
antigen antibody reaction

36.  When titanium is used no foreign body
reaction are seen.
 The implant material is an important factor
for Osseo integration to occur.

37. Biological process of implant
osseointegration
 The healing process of implant system is
similar to primary bone healing.
 Titanium dental implants show three stages
of healing

38.  OSTEOPHYLLIC STAGE
 When a implant is placed into the cancellous
marrow space blood is initially present between
implant and bone.
 Only a small amount of bone is in contact with
the implant surface; the rest is exposed to
extracellular fluids.
 Generalized inflammatory response to the
surgical insult.

39.  By the end of first week, inflammatory cells are
responding to foreign antigens.
 Vascular ingrowth from the surrounding vital tissues
begins by third day.
 A mature vascular network forms by 3 weeks.
 Ossification also begins during the first week and the
initial response observed in the migration of
osteoblasts from the trabacular bone which can be
due to the release of BMP’s.
 The osteophyllic phase lasts about 1 month.

40. OSTEOCONDUCTIVE PHASE
Once they reach the implant, the bone
cells spread along the metal surface laying
down osteoid.
Initially this is an immature connective
tissue matrix and bone deposited is a thin
layer of woven bone called foot plate

41.  Fibro-cartilaginous callus is eventually
remodeled into bone callus.
 This process occurs during the next 3
months
 Four months after implant placement the
maximum surface area is covered by
bone.

42.  OSTEOADAPTIVE PHASE
 The final phase begins approximately 4 months
after implant placement.
 Once loaded implants do not gain or loose bone
contact but the foot plates thicken in response
and some reorientation of the vascular pattern
may be seen

43.  Grafted bone integrates to a higher degree than
the natural host bone to the implant.
 To achieve optimal results an osseointegration
period of 4 months is recommended for implants
in graft bone and 4 to 8 months for implant
placed in normal bone.

44.  Bioactivity
 characteristic of an implant material that allows attachment to
living tissues, whereas a non bioactive material would form a
loosely adherent layer of fibrous tissue at the implant
interface
 Bioactive retention is achieved with bioactive
materials such as hydroxyapatite (HA), which
bond directly to bone

45. Factors influencing Osseointegration
 Biomaterial for dental implant
 Surface composition and structure
 Implant design
 Heat
 Contamination
 Primary stability or initial stability
 Bone quality
 Epithelial down growth
 Loading

46. Mechanism of Osseointegration
Blood clot (between fixture & bone)
Clot transformed by phagocytic cell
(1st to 3rd day)
Procallus formation
(containing fibroblasts & phagocytes)
Procallus becomes dense connective tissue
(Differentiation of osteoblasts & fibroblasts)
Callus (Osteoblasts on the fixture)
Fibro cartilagenous callus (between fixture & bone)
Bone callus (Penetrates & matures)
Prosthesis attached to the fixtures stimulating bone remodeling

47. Fibro-integration:
 Proposed by Dr.Charles Wiess
 Complete encapsulation of the implant with soft
tissues
 Soft tissue interface could resemble the highly
vascular periodontal fibers of natural dentition

48. Classification based on implant materials
1. Metallic implant
2. Ceramic and ceramic coated
3. Polymer and
4. Carbon compound

49. Metallic implant:
 Most popular material in use today is TITANIUM
 Other metallic implants are
stainless steel
cobalt chromium molybdenum alloy
vitallium

50. Metals and alloys in implants
Dental implants are constructed using metals and
alloys. These include titanium , tantalum , and alloys
of aluminium , vanadium , cobalt , chromium ,
molybdenum and nickel.
These materials are generally selected on the basis of
their strength.
The precious metals generally used in restoration such
as gold, platinum and their alloys are less frequently
used as dental implant.

51. Titanium
 Discovered in 1789 by Wilhelm Gregor.
 Represents only 6% of the earth crust.
 Industrial use started 60 years ago with use in
aerospace and defence because of it's light weight,
high strength and high melting point.
 Used as biomaterials in dental implants ,orthopaedic
and cardiovascular applications.
 Excellent biocompatibility, corrosion resistance, and
desirable physical and mechanical properties.

52. Dr. Wilhelm Kroll is known as the father of titanium
dentistry.
He successfully developed the deoxidation process of
titanium tetrachloride through a reduction process
with magnesium and sodium.
The result was a titanium sponge that could be melted
in an induction casting furnace into a solid alloy and
produced in long cast solid bars

53. General properties of titanium
 Melting point is 1680 degree
 High tensile strength
 Highly ductile
 Highly rigidity due to high modulus of elasticity
Low weight
 High corrosion resistance

54. American society for testing materials (ASTM)
classified titanium into grades; which vary according
to oxygen(0.18-0.40 wt%) iron (0.20-0.50 wt%) and
other impurities which includes nitrogen , carbon ,
and hydrogen.
Grade I is the purest and softest form , and have
moderately high tensile strength.
As the grade goes up, the stronger the titanium
becomes
Grade V contains aluminum and vanadium along with
titanium, making it stronger than grades I-IV

55. Advantage
 Strong
 Lightweight
 Corrosion Resistant
 Cost-efficient
 Non-toxic
 Biocompatible (non-toxic AND not rejected by the body)
 Long-lasting
 Non-ferromagnetic
 Osseointegrated (the joining of bone with artificial
implant)
 Long range availability
 Flexibility and elasticity rivals that of human bone

56. Medical grade titanium is used in producing:
 Pins
 Bone plates
 Screws
 Bars
 Rods
 Wires
 Posts
 Expandable rib cages
 Spinal fusion cages
 Finger and toe replacements
 Maxio-facial prosthetics

57. It is used to create a number titanium surgical devices:
 Surgical forceps
 Retractors
 Surgical tweezers
 Suture instruments
 Scissors
 Needle and micro needle holders
 Dental scalers
 Dental elevators
 Dental drills
 Lasik eye surgery equipment
 Laser electrodes
 Vena cava clips

58.  Dental Titanium
 Titanium has the ability to fuse together with living bone. This
property makes it a huge benefit in the world of dentistry.
 Titanium dental implants have become the most widely
accepted and successfully used type of implant due to its
propensity to osseointegrate.
 When bone forming cells attach themselves to the titanium
implant, a structural and functional bridge forms between the
body’s bone and the newly implanted, foreign object.
 Titanium orthodontic braces are also growing in popularity.
They are stronger, more secure and lighter than their steel
counterparts.

59. Future of Bio-medical Titanium
 It is expected that use within the biomedical industry
will only continue to grow for titanium in the coming
years. With the baby-boomer demographic
continuing to age and our health industry pushing
for people to live more active lives, it’s only logical
that the medical industry will continue researching
new and innovative uses for this popular metal alloy.
And with health care reform a current major issue,
titanium’s cost-efficiency adds even more appeal to
those looking to cut health care costs.

60.  Alfa-bio, Bredent, Nobel Biocare are the most widely
used dental implants.

61. Ceramic
Bioceramics and bioglasses are ceramic materials
that are biocompatible Bioceramics are an important
subset of biomaterials.
Bioceramics range in biocompatibility from the
ceramicoxides, which are inert in the body, to the
other extreme of resorbable materials, which are
eventually replaced by the materials which they were
used to repair.

62.  Bioceramics are used in many types of medical
procedures. A primary medical procedures where
they are used is as surgical implants.
 Though some bioceramics are flexible. The ceramic
materials used are not the same as porcelain type
ceramic materials.
 Rather bioceramics are closely related to either the
body's own materials, or are extremely durable metal
oxide

63. Available
1)Specialty steels
2) Cobalt base alloys
3) Titanium and titanium alloys
4) NiTiNOL
5) Zirconium alloys

64. Uses
 Ceramics are now commonly used in the medical
fields as dental, and bone implants.
 Artificial teeth, and bones are relatively
commonplace.
 Surgical cermets are used regularly. Joint
replacements are commonly coated with bioceramic
materials to reduce wear and inflammatory
response.
 Other examples of medical uses for bioceramics are
in pacemakers, kidney dialysis machines, and
respirators.

65. Advantages
 Porous, strong and non-brittle composition
 Rapid fibrovascularization
 No risk of disease-transmission
 Lightweight and easy to insert during surgery
 Easy to suture to extra ocular muscles
 Effortlessly hand-drilled without crumbling
 Non-dissolving
 Does not release soluble components
 Does not cause excessive tissue inflammation

74. Types of ceramic coatings
 Plasma spraying

75.  Vacuum deposition technique

76.  Sol-gel and dip coating methods

77.  Hot isostatic pressing
 Expensive
 The potential for contamination
 The necessity for removing the inert foil or other
encapsulating materials

84. Polymer and composites: