Transcript biocompatibility of dental materials
Slide 1
DENTAL
MATERIALS
(BIOCOMPATIBILIT
Y)
By
Head of Department
Dr Rashid Hassan
Assistant Professor
Science Of Dental Materials Department
Rawal institute of Health Sciences
Rawal College of Dentistry
Islamabad
1
Slide 2
BIOMATERIAL
“When a material is
placed within, or in
contact with the
human body, it is
referred to as
biomaterial”
OR
“A non living material
designed to interact
with the biological
system”
2
Slide 3
BIOCOMPATIBILITY
Defined as,
“The ability of a
material to elicit an
appropriate biological
response in a given
application in the
body.”
The material is said to
be “biocompatible”
when it possesses the
property of being non
destructive in a
biological system.
3
Slide 4
BIOMECHANICS
a)
b)
“Behavior of a material
in real structures is
known as mechanics”
“Biomechanics is
application of
mechanics to
biomaterials”
Biomechanics involve.
Limitation of a
material.
Restorative design.
4
Slide 5
ADVERSE EFFECTS FROM
DENTAL MATERIALS
Adverse effects may be,
Toxic.
Inflammatory.
Allergic.
Mutagenic.
These effects are differentiated on the
basis of histological and pathological
analysis of tissues.
5
Slide 6
TOXICITY
Earliest response
studied.
First screening test
for every material.
Materials may
release toxic
substances.
e.g.
lead containing
materials.
6
Slide 7
INFLAMMATION
Second type.
Activate immune
response of the
host.
May be due to
toxicity or allergy.
Inflammation
precedes toxicity.
e.g.
Pulpal and Periodontal
7
Slide 8
ALLERGY
Most Familiar to the general
public.
Body specifically recognizes
a material as a foreign body
and reacts
disproportionately to the
amount of material.
Involves all the dimensions
of the immune system.
Can be difficult to
differentiate from nonallergic inflammation or low
grade toxicity.
E.g. Latex.
8
Slide 9
MUTAGENIC REACTION
Occurs when the
components of the
materials alter the base
pair sequence of DNA.
May be due to direct /
indirect interactions.
Does not imply
carcinogenicity.
Metal ions from a
dental material (nickel,
beryllium and copper)
9
Slide 10
LOCAL and SYSTEMIC
EFFECTS OF MATERIALS
LOCAL EFFECTS:
Occur in the pulp of the tooth,
periodontium, nearby mucosa or
root apex.
Depends upon the ability of
material.
E.g. Nickel containing crowns.
10
Slide 11
LOCAL and SYSTEMIC
EFFECTS OF MATERIALS
SYSTEMIC EFFECTS:
Due to substances that gain
access to the body.
ingestion and absorption from the
gut, inhaled vapor, absorption
through oral mucosa or release
from the tooth apex.
11
Slide 12
LOCAL and SYSTEMIC
EFFECTS OF MATERIALS
SYSTEMIC EFFECTS:
May occur by blood or lymphatic
transport or simply by diffusion.
Systemic effect depends upon,
1. Duration and concentration of
exposure.
2. Excretion rate of substance.
3. Site of exposure.
12
Slide 13
MEASURING
BIOCOMPATIBILITY OF
DENTAL MATERIALS
1.
2.
3.
Biological response is related to
the use of a material.
Factors affecting biological
response:
Location of the material.
Duration of the material in the
body.
Stresses placed on the materials.
13
Slide 14
1. Location of the
material
Surroundings can be a soft tissue or a
hard tissue.
May be exposed directly to the blood,
tissue fluids or saliva or through a
barrier.
Might be placed externally or internally
to the oral epithelium.
14
Slide 15
2. Duration of the
material in the body
May be:
1. Short duration-> 4 – 6 minutes.
e.g. Impression materials.
2. Longer duration-> for ten years.
e.g. Fixed prosthesis.
Longer duration provides more time
to the material and body to react to
each other.
15
Slide 16
3. Stresses placed on the
materials
Stresses may be physical,
chemical or thermal.
Properties of the material comes
under consideration.
E.g. Strength of a material.
Fatigue stresses .
16
Slide 17
TESTS
FOR MEASURING
BIOCOMPATIBILITY
17
Slide 18
TYPES OF TESTS
1.
2.
3.
3 basic types of tests.
The in vitro test.
The animal test.
The usage test.
No single test can measure the
biological response accurately.
18
Slide 19
1. IN VITRO TEST
Performed outside the
organism.
First screening test to
evaluate biological
response of a new
material.
Conducted in test tube,
cell culture dish, flask
or other container.
Contact may be
direct/indirect.
19
Slide 20
1. IN VITRO TEST
ADVANTAGES
Relatively fast.
Inexpensive.
Easily
standardized.
Controlled
conditions.
Large scale
testing.
DISADVANTAGES
Lack of
relevance to in
vivo conditions.
Lack of complex
systemic coordinations.
20
Slide 21
2. THE ANIMAL TEST
Material placed into an
intact organism.
Commonly used
animals are mice, rats,
hamsters or guinea
pigs.
Other animals used are
cats, sheep's, dogs,
monkeys and baboons.
Distinct from usage
tests.
21
Slide 22
2. THE ANIMAL TEST
ADVANTAGES
Intact biological
system.
Act as a bridge
between in vitro
and usage test.
DISADVANTAGES
Expansive.
Difficult to
control.
May take months
or years.
Ethical concerns.
22
Slide 23
3. USAGE TEST
Performed in animals
or humans.
In case of humans it is
called as clinical trial.
Choice of animal is
limited.
Animals used should
be large, with anatomy
similar to the humans.
Human clinical trial is
the “gold standard”.
23
Slide 24
3. USAGE TEST
DISADVANTAGES:
Very costly.
In case of humans ethical
permission requires.
Prolonged time required for
results.
Legal liabilities.
24
Slide 25
TESTS USED TOGETHER
1.
2.
3.
No single test can evaluate
biocompatibility.
Three phases are recognized
Primary phase.
Secondary phase.
Usage phase.
25
Slide 26
TESTS USED TOGETHER
Usage
Progress of
testing
SECONDARY
PRIMARY
Number of materials
26
Slide 27
TESTS USED TOGETHER
PRIMARY PHASE
Performed initially for testing a
new material.
Often in vitro.
May also include some animal
tests for systemic toxicity.
27
Slide 28
TESTS USED TOGETHER
SECONDARY PHASE
Always conducted in animals.
Used to rule out any dermal irritation,
chronic toxicity or response upon
implantation.
Can also rule out inflammation, allergy
and sub lethal biological responses.
USAGE PHASE:Same as discussed previously
28
Slide 29
TESTS USED TOGETHER
Progress of
testing
Usage
SECONDARY
PRIMARY
Number of materials
29
Slide 30
CURRENT
BIOCOMPATIBILTY ISSUES
IN DENTISTRY
Latex:
Incidence rate 6% 7%
may cause localized
rashes or swelling,
dermatitis of hands
(eczema)
Nickel:
Incidence rate 10% 20%.
100% of patients
sensitive to palladium
will be sensitive to nickel.
30
Slide 31
CURRENT
BIOCOMPATIBILTY ISSUES
IN DENTISTRY
Nickel:
But only 33% of
individuals allergic to
nickel will be allergic to
palladium.
Etiology not known.
Beryllium:
Only used in 1% – 2%
by weight in Ni-Cr
alloy.
Carcinogenic effects.
Can cause “beryllosis”.
31
Slide 32
QUESTIONS
????
32
DENTAL
MATERIALS
(BIOCOMPATIBILIT
Y)
By
Head of Department
Dr Rashid Hassan
Assistant Professor
Science Of Dental Materials Department
Rawal institute of Health Sciences
Rawal College of Dentistry
Islamabad
1
Slide 2
BIOMATERIAL
“When a material is
placed within, or in
contact with the
human body, it is
referred to as
biomaterial”
OR
“A non living material
designed to interact
with the biological
system”
2
Slide 3
BIOCOMPATIBILITY
Defined as,
“The ability of a
material to elicit an
appropriate biological
response in a given
application in the
body.”
The material is said to
be “biocompatible”
when it possesses the
property of being non
destructive in a
biological system.
3
Slide 4
BIOMECHANICS
a)
b)
“Behavior of a material
in real structures is
known as mechanics”
“Biomechanics is
application of
mechanics to
biomaterials”
Biomechanics involve.
Limitation of a
material.
Restorative design.
4
Slide 5
ADVERSE EFFECTS FROM
DENTAL MATERIALS
Adverse effects may be,
Toxic.
Inflammatory.
Allergic.
Mutagenic.
These effects are differentiated on the
basis of histological and pathological
analysis of tissues.
5
Slide 6
TOXICITY
Earliest response
studied.
First screening test
for every material.
Materials may
release toxic
substances.
e.g.
lead containing
materials.
6
Slide 7
INFLAMMATION
Second type.
Activate immune
response of the
host.
May be due to
toxicity or allergy.
Inflammation
precedes toxicity.
e.g.
Pulpal and Periodontal
7
Slide 8
ALLERGY
Most Familiar to the general
public.
Body specifically recognizes
a material as a foreign body
and reacts
disproportionately to the
amount of material.
Involves all the dimensions
of the immune system.
Can be difficult to
differentiate from nonallergic inflammation or low
grade toxicity.
E.g. Latex.
8
Slide 9
MUTAGENIC REACTION
Occurs when the
components of the
materials alter the base
pair sequence of DNA.
May be due to direct /
indirect interactions.
Does not imply
carcinogenicity.
Metal ions from a
dental material (nickel,
beryllium and copper)
9
Slide 10
LOCAL and SYSTEMIC
EFFECTS OF MATERIALS
LOCAL EFFECTS:
Occur in the pulp of the tooth,
periodontium, nearby mucosa or
root apex.
Depends upon the ability of
material.
E.g. Nickel containing crowns.
10
Slide 11
LOCAL and SYSTEMIC
EFFECTS OF MATERIALS
SYSTEMIC EFFECTS:
Due to substances that gain
access to the body.
ingestion and absorption from the
gut, inhaled vapor, absorption
through oral mucosa or release
from the tooth apex.
11
Slide 12
LOCAL and SYSTEMIC
EFFECTS OF MATERIALS
SYSTEMIC EFFECTS:
May occur by blood or lymphatic
transport or simply by diffusion.
Systemic effect depends upon,
1. Duration and concentration of
exposure.
2. Excretion rate of substance.
3. Site of exposure.
12
Slide 13
MEASURING
BIOCOMPATIBILITY OF
DENTAL MATERIALS
1.
2.
3.
Biological response is related to
the use of a material.
Factors affecting biological
response:
Location of the material.
Duration of the material in the
body.
Stresses placed on the materials.
13
Slide 14
1. Location of the
material
Surroundings can be a soft tissue or a
hard tissue.
May be exposed directly to the blood,
tissue fluids or saliva or through a
barrier.
Might be placed externally or internally
to the oral epithelium.
14
Slide 15
2. Duration of the
material in the body
May be:
1. Short duration-> 4 – 6 minutes.
e.g. Impression materials.
2. Longer duration-> for ten years.
e.g. Fixed prosthesis.
Longer duration provides more time
to the material and body to react to
each other.
15
Slide 16
3. Stresses placed on the
materials
Stresses may be physical,
chemical or thermal.
Properties of the material comes
under consideration.
E.g. Strength of a material.
Fatigue stresses .
16
Slide 17
TESTS
FOR MEASURING
BIOCOMPATIBILITY
17
Slide 18
TYPES OF TESTS
1.
2.
3.
3 basic types of tests.
The in vitro test.
The animal test.
The usage test.
No single test can measure the
biological response accurately.
18
Slide 19
1. IN VITRO TEST
Performed outside the
organism.
First screening test to
evaluate biological
response of a new
material.
Conducted in test tube,
cell culture dish, flask
or other container.
Contact may be
direct/indirect.
19
Slide 20
1. IN VITRO TEST
ADVANTAGES
Relatively fast.
Inexpensive.
Easily
standardized.
Controlled
conditions.
Large scale
testing.
DISADVANTAGES
Lack of
relevance to in
vivo conditions.
Lack of complex
systemic coordinations.
20
Slide 21
2. THE ANIMAL TEST
Material placed into an
intact organism.
Commonly used
animals are mice, rats,
hamsters or guinea
pigs.
Other animals used are
cats, sheep's, dogs,
monkeys and baboons.
Distinct from usage
tests.
21
Slide 22
2. THE ANIMAL TEST
ADVANTAGES
Intact biological
system.
Act as a bridge
between in vitro
and usage test.
DISADVANTAGES
Expansive.
Difficult to
control.
May take months
or years.
Ethical concerns.
22
Slide 23
3. USAGE TEST
Performed in animals
or humans.
In case of humans it is
called as clinical trial.
Choice of animal is
limited.
Animals used should
be large, with anatomy
similar to the humans.
Human clinical trial is
the “gold standard”.
23
Slide 24
3. USAGE TEST
DISADVANTAGES:
Very costly.
In case of humans ethical
permission requires.
Prolonged time required for
results.
Legal liabilities.
24
Slide 25
TESTS USED TOGETHER
1.
2.
3.
No single test can evaluate
biocompatibility.
Three phases are recognized
Primary phase.
Secondary phase.
Usage phase.
25
Slide 26
TESTS USED TOGETHER
Usage
Progress of
testing
SECONDARY
PRIMARY
Number of materials
26
Slide 27
TESTS USED TOGETHER
PRIMARY PHASE
Performed initially for testing a
new material.
Often in vitro.
May also include some animal
tests for systemic toxicity.
27
Slide 28
TESTS USED TOGETHER
SECONDARY PHASE
Always conducted in animals.
Used to rule out any dermal irritation,
chronic toxicity or response upon
implantation.
Can also rule out inflammation, allergy
and sub lethal biological responses.
USAGE PHASE:Same as discussed previously
28
Slide 29
TESTS USED TOGETHER
Progress of
testing
Usage
SECONDARY
PRIMARY
Number of materials
29
Slide 30
CURRENT
BIOCOMPATIBILTY ISSUES
IN DENTISTRY
Latex:
Incidence rate 6% 7%
may cause localized
rashes or swelling,
dermatitis of hands
(eczema)
Nickel:
Incidence rate 10% 20%.
100% of patients
sensitive to palladium
will be sensitive to nickel.
30
Slide 31
CURRENT
BIOCOMPATIBILTY ISSUES
IN DENTISTRY
Nickel:
But only 33% of
individuals allergic to
nickel will be allergic to
palladium.
Etiology not known.
Beryllium:
Only used in 1% – 2%
by weight in Ni-Cr
alloy.
Carcinogenic effects.
Can cause “beryllosis”.
31
Slide 32
QUESTIONS
????
32