32 SERIES ( VIDEO NO 47)

have ribbon this is dr. aamil from Team
MDS conquer in this video we are going
to discuss 32 important points from the
topic of dental materials point number 1
compressive stress it is the internal
resistance to a loop that tends to
compress or shorten embody number 2
tensile stress it is the internal
resistance to a load that tends to
stretch or elongated body
number 3 is shear stress it is the
resistance to the sliding motion of a
body over another by twisting it or shun
load number 4 the material used for
Knoop hardness tested diamond of rhombic
shape here the long axis of indentation
is measured the hardness value is
independent of the ductility of material
number 5 the material used for vickers
test that is the diamond pyramid test is
a diamond of square base shape even in
this the diagonal length of indentation
is measured number 6 the material used
for rockwell test is diam end of conical
shape in this the penetration depth is
measured number 7 the material used for
brenell's to steel ball in this the
diameter of indentation is measured
number 8
Brunell and rockwell tests are
classified as toe hardness test and they
are not suitable for brittle materials
number nine the nope
and Vickers gist are classified as micro
hardness test both of this tests employ
loads less than 9.8 Newtons pond number
10 the shore and bark coal tests are
used for measuring the hardness of
rubbers and plastics member 11 the
Brinell test is one of the oldest is
used for determining the hardness of
materials and it is directly related to
proportional limit and the ultimate
tensile strength of dental gold alloys
number 12 in the stress-strain graph the
slope of straight line is up to the
proportional limit represents modulus of
elasticity number 13 in this graph the
area below the modulus within the
elastic range is known as resilience
and the area under the entire length of
the line up to the fracture strength
represents toughness number 15 the
ultimate tensile strength is the stress
at the point of fracture it is also
known as breaking point number 16 the
contact angle is the angle formed by the
adisyl within the other end at their
interface the less the contact angle the
more the wettability and spreadable
number 17 ductility is the ability of a
metal to be drawn into a wire under
tensile load without rupture this
duct-taping can be measured by percent
elongation and cold blend test number 18
gold is the most jock tale and malleable
pure metal and silver is second platinum
ranks third in ductility and copper
ranks third in malleability number 19
coefficient of thermal expansion of
tooth enamel is closest to type two GLC
followed by silicates number 20
Newtonian fluid it is known as ideal
liquid as the shear stress is
proportional to this strain step number
21 dilute and liquid in this the
viscosity of liquid increases with
increase of shear stress
number 22 thixotropic fluid in this the
viscosity of fluid decreases under
pressure
number 23 pseudo plus tooth here the
viscosity decreases with increase in
shear stress until they reach a constant
value number 24 viscoelastic it is a
characteristic of polymers the behave as
elastic solids or Springs and as a
viscous liquids number 25 might sinem
flexibility it is defined as the
flexural strain that occurs when the
material is stressed to its proportional
limit remember 26 one of the most
commonly used method to define and
measure color quantitatively x' moon
cell system in this system the
parameters of color are represented in
three dimensions number 27 the two
different testing techniques use it to
determine tensile strength our direct
tensile strength and diametral
compression strength number 28
brazilian cylinder splitting test is the
type of diametral compression test and
it is widely used test to determine the
ultimate tensile strength of brittle
materials number 29 eutectic alloy is an
alloy for which the component metals
have limited solid solubility number 30
peritectic alloy it is the addition to
eutectic system here the limited solid
solubility of two metals can result in
peritectic transformation
number 31 energy required to liquefy is
known as latent heat of fusion number 32
the brightness becomes more intense
color appears to change this phenomenon
is known as basalt Brooke effect that's
it for today's session guys keep on
reversing this points all the best thank
you