Term
| Federal Food, Drug, and Cosmetic Act of 1938 — |
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Definition
Drug premarket approval, removal of fraudulent devices, proper labeling.
•set up situation where you neededpre-market approval to market a particular drug
•if you were to market a drug, had to go to govt and get pre-market approval to market it
•made sure that they had the power to remove fradulent devices
•proper labeling of drugs required |
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Term
| Medical Device Amendments of 1976 — |
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Definition
•Class I (least regulated) to Class III (most regulated). |
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Term
| Safe Medical Devices Act of 1990 — |
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Definition
expanded FDA authority in premarketing and postmarketing stages. Established tracking for some devices.
response to breast implant controversy |
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Term
•a lot of law suits involved with breast implant issue
•that a lot of companies got completely out of the medical device field
•including manufacturers who supplied RAW materials
resulted in Biomaterials Access Assurance Act of 1998
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Definition
| limits the liability of biomaterials suppliers that are used to make medical devices |
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Term
•class 1 devices
•if you sell a tongue depressor, and it leaves splinters in peoples tongues
•no1 will buy it
•you wont be able to sell it
•general market control –
•if you screw it up, no1 will buy it
•not necessarily stuff that will significantly hurt some1
•premarket approval is not required for this
•in general
•materials that are put ontissue
•in contact with skin/gingiva = class 1 devices
•crowns are included (although placed on prepared tooth)
•dentures are included
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Definition
–A device for which market controls are sufficient to ensure safety and effectiveness.
–Standards and premarket approval are not necessary.
–Examples — Most short-term devices
•dental floss
•tongue depressor
•surgeon’s glove
•dentures, crowns |
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Term
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Definition
–General market controls are insufficient but there is sufficient information for establishment of a performance standard.
–Premarket notification is necessary.
–Examples —
•Oxygen mask
•blood pressure cuff
•ultrasound imager
•dental restorative materials (amalgams and composites)
•root form dental implants (classification change as of 4/04). |
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Term
| root form dental implants |
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Definition
•placed in live bone – come thru bone and soft tissue
•only device that is placed in living bone THAT IS NOT A CLASS 3 DEVICE
•a lot of implants are sold with abutments (which is the part that goes thru the skin)
•abutment - is a class 2 device
•class 2 and 3 device in the same package – did not work with the FDA
•so root form dental implants were reclassified in 04’
•only implantable device that is a class 2 |
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Term
•class 3
•when fda first established this class – general idea was
•if you had a new device, you would have to do an
•IDE(investigational device exemption) and a
•PMA – pre market approval documentation
•and get this thru the FDA
•could take several years bc it involves human clinical studies
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Definition
–Premarket Approval (PMA). Insufficient information for reasonable safety and effectiveness, required to have PMA.
–These require some level of testing. See 510k rule.
–Examples —
•Intraocular lenses
•replacement heart valves,
•orthopaedicimplants
•blade form dental implants
•root form dental implants. |
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Term
•LOOPHOLE – 510k rule
•substantial equivalence rule
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Definition
•everything you run across in the clinic has been 510ked into existence
•means – if the device is substantially equivalent to something that was on the market/already on the market prior to 1976
•do not have to completely test it
•as soon as this law came out – people started to make incremental changes in their materials
•saying this is the same as what we were making before 1976 – essentially 510k application
99.9% of everything that is on the market today has been 510 k approved |
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Term
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Definition
•510 k that has data with it (you can actually make some claims)
•allows you to make claims for ur device
•FDA regulates CLAIMS you can make for your device
•you cannot make outrageous claims unless you have DATA to support what ur making claims for |
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Term
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Definition
- The ability of a material (biomaterial) to perform with an appropriate host response in a specific application.
- Determined by the biomaterial and the host response
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Term
Biomaterial
For each biomaterial or device the definition of biocompatibility is different. |
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Definition
A biomaterial is a nonviable material used in a medical device intended to interact with biological systems
•some of these now that are coming out on market fit in biologics category that are viable
•artificial skin now
•live artificial skin with live cells in it
•sold for diabetic ulcer tx for burn victims
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Term
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Definition
•surface characteristics
•what your body, cells, tissue sees when you implant something
•they see whats on the surface
•bulk stability –
•you do not want bulk Instability
•èyou do not want a material that will release things –
•mechanical properties
•cannot use silicone rubber for joint replacement
•not stiff enough
•will not use stainless steal for breast implants |
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Term
•HOST RESPONSE – we have the least control over |
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Definition
•cellular level
•toxicity
•mutagenicity
•carcinogicity
•^these 3 terms make up tripartitie testing
•new biomaterial – you can send to biomaterials lab some place
•they can do these testing invitro with cell lines
•to determine whether cells have toxigenic, mutagenic response, etc.
•systemic/host level
•can have
•inflammatory response
•allergic response to the medical device |
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Term
| interface is mediated by the environment |
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Definition
• Saliva
• Blood
•heart valve
• Extracellular matrix proteins
•device planted in tissue
• Cells (macrophages, fibroblasts, osteoblasts)
•device planted in tissue
• Mineral
•implants that are put in bone
•HAP most cases |
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Term
COMPROMISED BIOCOMPATIBILITY can be based on
- changes in biomaterials |
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Definition
•Corrosion/degradation of a material
•Release of component materials
•Mechanical breakdown
–total hip replacements undergo fatigue
–they breakdown |
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Term
COMPROMISED BIOCOMPATIBILITY can be based on
- changes in HOST RESPONSE |
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Definition
•Systemic problems (diabetes) leading to changes in host response
•Hypersensitivity
– Immediate type I
– Delayed type IV |
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Term
| allergic rxns in dentistry - most common .. |
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Definition
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Term
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Definition
–allergic asthma and rhinitis
–food and drug reactions
–reactions to insect stings. |
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Term
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Definition
–Immune response mediated by T cells, usually CD4
–Cytokines are released
•macrophage activation and local damage
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Term
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Definition
Latex gloves
Methacrylates
Disinfectants
Anesthetics |
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Term
| most common allergens continued.. |
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Definition
Metals
–mostly was women who were allergic to Ni
–a lot of men now have piercings
•they now too have Ni allergies, evened out a bit
Eugenol
Impression materials
–Polyethers |
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Term
Common allergens
most common is Ni (10-15% of population)
-most of this has been eliminated from use |
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Definition
Nickel
Rubber compounds
Mercuric chloride
Cobalt salts
Thimerasol
Benzoyl peroxide
Fragrance mix |
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Term
Hg and Biocompatibility
•elemental mercury is not toxic
•UNLESS made into vapor
•carpets not in dental operatories anymore
•if you drop small piece of amal and you grind it into carpet – you increase the surface area of it tremendously
•mercury can VAPORIZE and you can inhale this
•once in your body à becomes organic mercury compound/salt
•èsalts are more toxic than organic
•èmethyl mercury (organic mercury compound) is 7 x as toxic vs. elemental mercury |
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Definition
Hg forms
– Elemental – vapor or liquid
• Amalgam vapor
–Organic (methyl Hg)
•Highly toxic (~7x as toxic as elemental mercury)
Exposure (daily)
–Atmosphere (vapor, 0.12 µg)
–Drinking water (inorganic, 0.05 µg)
–Food (non fish – inorganic, 20 µg)
FISH ( methyl Hg, 3.76 µg |
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Term
·Workplace vapor levels, OSHA Threshold Limit Value (TLV) |
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Definition
how much mercury your allowed to be exposed to
· 50 µg/m3 for 8 hr day, 5 days per week
•reported levels are way less than threshold values
•when you place amal –
•theres the most risk for vapor
•bc as the amalsets
•it becomes a more stable material
•less likely to give off mercury
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Term
·9 occlusal amalgams = 1% of work place safety levels that your allwoed to be exposed to in a manufacturing plant(TLV) |
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Definition
·One saltwater seafood meal per week
· Urine levels of 5-20 µg/L (WHO)
· 2 – 8 times exposure from dental amalgam vapor |
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Term
•whenever you take any material and you grind it up into particles – your BOUND to get an inflamm response to it
•when drilling it out
•get rid of all the materials |
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Definition
-foreign body giant cells
-capable of producing lots of cytokines and inflamm mediators
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Term
| Total hip replacement (Class III) articulating joint surface |
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Definition
•one of the problems with these implants is THEY WEAR
•solid metal ball on a polyethylene liner
•polyethylene liner – can release wear particles over time (implants that are in for 15-20 yrs)
•grind this up into small particles
•can get a very nasty inflamm response to these particles
•taking a material that is perfectly biocompatible in bulk form
•but when grinded up into small particles causes a TREMENDOUS inflamm response
•tissue response is more related to the surface area of the material than the material itself
•when you grind up into particles è tremendously increase the surface area that the body responds to
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Term
•good example of what can happen with a class 3 device over long periods of time bc of wear and breakdown of materials into particles
polyethylene particles from hip joint replacement/implant |
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Definition
particles are generated int he synovial joint
- activation of osteoclasts and FBGC
•the most biocompatible materials
•if you grind them up into little particles – they cause a nasty response |
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