implant lecture Flashcards
even pure titanium is commonly mixed with what?
6% aluminum and 4% vanadium
alumnim does what
decreases weight and increases strength
vanadium does what?
protects from corrosion
explain titanium properties compared to others.
greater than stainless steel and human bone tissue
speed of oxidation and thickness of the layer affects what?
corrosion rate of each metal
what metal is better at avoiding corrosion in water?
gold
what metal is better at avoiding corrosion in acid?
titanium
after implant is inserted into the body body tissue, the surface oxide of the titanium implant continuously grows by what?
inward transport of oxygen and outward transport of metal atom to form the oxide metal line.
the concentration of Titanium ions is _________ as the distance from the oxide-metal increases.
decreased.
the tissue implant interface is determined by what?
region of extracellular matrix (collagen & chondroitin sulfate) and Ti oxide, which is located between bulk Ti and cells.
outermost surface of titanium oxide has what?
unsaturated bonds, allowing it to easily bind to any contaminants when Ti surface is exposed to air.
if implant contaminated, what happens to tissue attachment?
decreased because unsaturated bonds bind to contaminants instead of extracellular matrix proteins
what is radio-frequency discharge?
improves implant surface properties. provides plasma-cleaning treatment. argon gas delivered from device, strips contaminants, sterilizes surface and reforms oxide layer. decreases surface angle contact
tricalcium phosphate (TCP) properties
low crystallinity, higher biosolubilty, for bone defects.
hydroxyapatite (HA) properties
higer crystallinity, not readily biosorable, used for coatings for implants
advantages of HA
high compressive strength, good wear properties, and biological compatability
disadvantages of HA
low tensile strength, therefor can only apply as thin layer. also low shear strength
method to coat implants with HA
plasma coating
optimal thickness of HA
50 μm
after dental implant is inserted, what happens?
undifferentiated mesenchymal cells from bone marrow attach to surface of implant material
cellular attachment facilitated by what?
adhesive proteins like firbonectin and vitronectin
While the cells attach to the surface of the implant material, the
cells undergo _________________. this process is promoted by what?
differentiation to osteoblasts. by osteogenic proteins such as osteogenin
as a result of implantation, 2 types of bone form?
distant bone and contact bone
host osteogenic response to implant materials 4 steps
attachment, differentiation, osteogenesis, mineralization
distant bone formation occurs when what?
failure of osteogenic cell attachment to the implant surface
layer of soft fibrous tissue (FT) between
the implant material (I) and solid bone tissue
distant bone
contact bone formation is an indication of what?
succesfull dental implantation
what is contact bone?
when bone comes in contact with implant. no fibrous tissue
