1. Biocompatibilify Of Material For Use In The Body Flashcards
Los
What is a biomaterial?
- biological material
↳ synthetic (e.g.ceramics, polymer, metal)
OR
↳ natural → used as part of an implanted medical device to replace an organ or bodily function
Eg of materials used in dent
• Amalgam
• Glass ionomers
• Gold
• Composites
• Ceramics
• Titanium
• Bone filling products
• Teeth bleaching products
Now looking at more tissue engineering
Eg of biomaterial applications around body
Potential biocompatibility concern categories to consider
What is biocompatibility?
Biocompatibility is the ability of a material to perform with an APPROPRIATE HOST response in a given SPECIFIC APPLICATION. (Williams 1987)
Materials used in dent come into direct contact with?
• Hard tissues of the teeth
• The soft tissue of the oral mucosa
• The pulp & periapical tissues
Key elements that materials in dentistry should be?
(Word better)
•Non-Toxic (both to patient and staff)
• Non-irritant (in the mouth and other tissues)
• Minimal inflammation (acute, not chronic)
•Tissue integration (e.g. Implants)
•Physical and mechanical properties (for intended application)
•Not be mutagenic or carcinogenic
Effect the body has on implant material?
1
- first thing to happen is protein cover implant in layer, generally good as want to have cells adhering and new tissue formation
- however not good in blood contacting material EG stent or heart valve as thrombi will form
3
- if degradable material need to consider biocompatibility and enzyme effect
- what breakdown products will be, effect pH, etc
4
- some metals used are corrosive
Effects the implant has on the body
How is biocompatibility assessed?
Factors influencing biocompatibility?
More info 13 minutes onwards on lecture vid
Standards that regulate the measurement of biocompatibility
- International Organization for Standardization (ISO)
↳ international standard-setting body composed of representatives from various national standards organizations
(ISO standard 10993 concerns Biological evaluation of medical devices Part 5: Tests for cytotoxicity- invitro methods)
- American National Standard Institute/American Dental Association (ANSI/ADA) (1979/1982)
Biocompatibility involves 2 components ?
How do we test biocompatibility?
More info in lecture but have not written 18 minutes
Requirements for biocompatibility in vitro testing methods
SSQ
Test methods to assess biocompatibility
- Do adverse actions usually happen with dental biocompatibility
- What adverse effects may occur?
What tissues interact with dental materials and what can they be classified into?
Toxicity risks on practitioner and staff?
BIOCOMPATIBILITY OF COMMON DEMTAL MATERIALS
AMALGAM
- Concern raised over mercury vapour released during manipulation, placement or removal of amalgam
↳ Amount usually minimal & potential of toxic reaction patients is less - Careful handling of mercury reduces risk to dentist & staff
- usu harmless to gingival tissues
BUT some Lichenoid episodes reported - No major adverse responses reported
BIOCOMPATIBILITY OF COMMON DEMTAL MATERIALS
Resin based composites
*Various components may be released from resin composite restorations
into the oral environment, BUT few systemic adverse effects documented
*Those reported have been associated with numerous organic compounds
(e.g phosphorus-dentine bonding agents, restorative materials) effects of
which are unknown
*Incomplete polymerisation leads to degradation, leaching, imperfect
bonding, polymerisation shrinkage
*Adverse local pulp and dentin reactions,
may be associated with the development of recurrent caries, and pain
- Increased plaque adhesion and Lichenoid episodes reported
BIOCOMPATIBILITY OF COMMON DEMTAL MATERIALS
GIC (glass ionimer cements)
*No evidence of systemic effect
*May see some minor irritation of the pulp, short-lived usually followed by rapid recovery
*Any irritation to the pulp, is more likely to be caused by hydraulic
pressure/etching during placement
*Cytotoxic substances like TEGMA & HEMA can be released from
unset or partially cured composites, these can diffuse through the dentin & cause pulpal inflammation
*No major adverse reactions reported in gingival tissue
Overall Good biocompatibility !
BIOCOMPATIBILITY OF COMMON DEMTAL MATERIALS
Gold foil and cast alloys
- Used for making crowns, bridges and dentures
*Inert, sensitivities are rare
*Potential pulp reactions due to condensation
*Rare allergic reactions to alloy metals
BIOCOMPATIBILITY OF COMMON DEMTAL MATERIALS
Ceramics
*No known reactions except wear on
opposing dentition and restoration
*Generally good biocompatibility
All dental materials in current use are
considered to be ACCEPTABLE
They show biocompatibility with local tissues:
*When properly handled and carefully placed in the oral
cavity
*Adverse systemic reactions are RARE, self-limiting, and tend
to be of an allergic nature
*Local reactions have been documented in only a small
percentage of individuals
SUMMARY
