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Biocompatibility ( biomaterial/bioacceptance)
- Being harmonious with life and not having toxic or
injurious effects on biologic function.
- Measured on the basis of:
1. Local cytotoxicity (pulp, and mucosal response)
2. Systemic responses
3. Allergenicity
4. carcinogenicity
Requirements for biocompatibility of dental material
1. It should not be harmful to the pulp and soft tissues
2. It should not contain toxic diffusible substances that
can be released and absorbed into the circulatory
system to cause systemic response.
3. It should be free of potentially sensitizing agents that
are likely to cause an allergic response.
4. It should have no carcinogenic potential
Biomaterial- any substance other than a drug that can be
used for any period as a part of a system that treats ,
augments, or replaces any tissue, organ or function
of the body.
Tests fo Evaluation of Biocompatibility
1. Group I:Primary Test – consists of cytotoxic evaluations (
Genotoxicity test)
2. Group II: Secondary Tests- (implantation tests)evaluated
for its potential to create systemic toxicity, inhalation
toxicity , skin irritation and sensitization.
Irritation- is an inflammation brought about without
intervention of an antibody or immune system.
Sensitization- an inflammatory response requiring the pax
of an antibody.
Allergen a substance that is not primarily irritating on the
first exposure but produces rxns more rapidly in animals
of appropriate genetic constitution on subsequent
exposure to similar conc.
3. Group III: Preclinical Tests- efficacy and usage test
after it successfully passes the primary and secondary
test.
a. Pulp and Dentin Usage test
b. Pulp capping and pulpotomy usage test
c. Endodontic usage test
Anatomy of the Tooth
Allergic Responses to Dental Materials
 Allergic Contact Dermatitis
- Most common occupational disease
- Usually occurs where the body surface comes in direct
contact with the allergen, eg. Allergy to latex products
 Allergic contact stomatitis
- Most common adverse reaction to dental materials
- Definitive diagnostic test is a patch test
- Symp: hyperemia, edema, vesicle formation, & itching
- Common allergens: chronium, cobalt mercury, eugenol,
components of resin based materials, colophonium and
formaldehyde
- “Burning Mouth Syndrome”
- Others, mouthwashes, dentrifices, toical medications like
lozenges and cough drops
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The Mercury Controversy
Minamata disaster of 1970. Minamata Bay, Japan
Methylated mercury poisoning
Less than 0.01% of Elemental mercury is absorbed
with 8 to 10 amalgam restorations in the mouth.
Elemental mercury poisoning- paresthesia of the
extremities, lips, and tongue, ataxia( gait disturbance),
concentric constriction of visual fields( tunnel vision)
Micromercurialism hypersensitivity- extremely small
amounts of mercury with the signs and symptoms of
mercury poisoning( cutaneous patch test)
Allergy to nickel
Allergy to berryllium
 MINIMIZING DENTAL IATROGENESIS
- Creation of side effects, problems, or complications
resulting from treatment
- RDT- 1mm or less all categories
- PTI- the response values of pulp,
- RDF- secondary dentin as a response of the pulp
 PULP RESPONSES
Amalgam
2. Chemically cured resin composites
3. Visible light cured resin composites
4. Zinc phosphate cement
5. Glass ionomer cement
6. Resin – Based composite cements( dual cure)
7. Conditioning agents
8. Bonding agents
Influence of patient on pulp response
At age 55, the volume of tissue is about one fifth that at
age 25 including the blood supply.
1.
 MICROLEAKAGE
- Can be controlled but not completely eliminated
 DENTIN HYPERSENSITIVITY
Factors to consider with DH
1. The age and sex of the patient
2. The age of the tooth
3. The amount of sclerosis present
4. The proximity of the pulp (RDT)
5. The presence or absence of CH liners
6. The depth of carious lesions versus the thickness of
of RDF
 PULP CAPPING
 ENDODONTICS
ANY QUESTIONS !!???