biocomp

Question 1

define biomatreial

Answer 1

material that is placed in or being in contact with the human body and designed to interact with a biological system

Question 2

define biocompatible

Answer 2

ability of a material to perform its job without inappropriate host response;

as a material , it is harmonious with life and not having toxic or injurious effects on biological function

Question 3

define biotolerability

Answer 3

ability of a material to reside in the body for long periods of time with only low degrees of inflammatory rxn

Question 4

biocomp. materials hould be harmless to ALL tissues, not contain toxic or leachable/diffusable substances, and should be free of substances that cancause sensitizations or allergic rxns

Answer 4

ye

Question 5

what does metabolism mean in the context of bicomp materials?

Answer 5

• how the body breaks down the material (the metabolites it produces, and how fast the material is processed

Question 6

what does distribution mean in the context of biocomp. materials?

Answer 6

-where the chemical resides in the body; water-sol will distribute throughout the body as we are made up of a lot of water; lipid-sol accumulate in fat; can also accumulate in bones or other organs

Question 7

define dose

Answer 7

amount of exposure to a potentially toxic agent; usually measured in mg/kg or mg/L

Question 8

define lethal dose 50

Answer 8

LD50 or LC50 = dose that causes 50% death in test animals

a high LD50/LC5- = requires more dose to kill = less toxic

Question 9

what are some problems of ysing LD50/LC50 to measure toxicity?

Answer 9

• measure acute effects–>no info about chronic exposure and effects
• calculated based on exposure to one chem, does not account for interactions

Question 10

biocompatibility does not take into account just effects on patient, but also dentist and dental staff

Answer 10

ye

Question 11

adverse rxns to dental materials are NOT COMMON; happens 1:1000 or 1:10000 of all dental txs; however, of the adverse rxn, skin and mucosal rxns are the most common

Answer 11

ye

Question 12

why is the risk greater to dental staff than pt?

Answer 12

bc we are chronically exposed to it; can range from cumulative irritation to severe allergic responses;

e. g. HEMA, TEGDMA, and camphoroquinone may activate immune cells
- we can also inhale particles

Question 13

what are the types of harmful interactions? where can they develop?

Answer 13

harmful interactions:

• hypersensitivity and allergy
• toxicity, inflamm, mutagenicity, and carcinogenicity
• sensitivity
• corrosion

can develop LOCALLY (irritation) or SYSTEMICALLY (dermatological, neural)

Question 14

what are some big signs of latex allergy? what should you do if they go into shock?

Answer 14

• rush, dermatitis, excema
• chronic exposure: swelling, edema, wheezing, asthamtic rxn, anaphylaxis
• call 911, ibnject adrenaline, oxygen should be applied

Question 15

10-20% of pop have nickel allergies; more women than men; 100% of pts allergic to Pd are allergic to Ni

Answer 15

ye

Question 16

why might dental amalgam not be biocomp?

Answer 16

• thermoconductivity to pulp

- corrosion & marginal leakage; sometimes causes lichenoid lesions

Question 17

how are composite resins implicated in biocomp?

Answer 17

• may have some estrogenic effects
• incomplete pol = degradation, leaching, imperfect bonding –> contact dermatitis
• can have allergic rxn to methacrylate
• poly shrinkage….
• lichenoid lesions

Question 18

how are glass ionomers documented in biocomp?

Answer 18

• early pulpul rxns, but followed by rapid recovery
• hydraulic pressure when placing may irritate pulp
• high biocomp.otherwise

Question 19

the only problem with biocomp with ceramic is wear on opposing teeth or restos

Answer 19

ye

Question 20

what regulatory bodies govern use of dental materials?

Answer 20

• american national standard institute (ANSI/ADA

- international standards association (ISO)

Question 21

what are the types of tests used in biocomp testing?

Answer 21

• primary (cell-culture dish, test tube)–here, can test the rxn of certain oral tissues to the material, such as change in cell number, growth or death rate, metabolic rate, cell function; good bc it is simple, repeatable, inexpensive, fast, and standardized, BUT lacks relevance to in vivo usage;
• secondary (in animal, but not human) – expensive, difficult to controlm tajes time, ethical problem, relevance?–but can see immune response, systemic tox, and mutagenicity
• usage tests (human, clinic test)– relevant to clinical usage but complicated, expensive, interpretation ethics, time consuming

important to remember that just because something doesn’t pass the primary test deos not mean it is harmful; e.g. ZOE is v toxic in in vitro testing, but not in clinical trials

Question 22

usually for something to be approved it muchpass all 3 tests; however, canbe approved with the “510 k” approval–>means you take data and test results others found on the material that matches yours–>speeds up the approval time and research time

Answer 22

ye