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So I think we can go on...
My topic today is micro movements on implant abutment interfaces
Causes and consequences and
this brings us to the first question why we should have
a closer look to the mechanics of implant abutment interfaces
if you ask the implant companies they always would have
we've got no problems with the mechanic.
We have no screw loosening perhaps
parts of a million or something like this: but then is the question
why we find into literature and in some studies
these results. Find fractured
implant components and we find
broken binding screws. Loosened
binding screws and perhaps some damaged implants,
and we also see that there is a bone lost
surrounding the most implants especially
down to the first thread. And the consequences of this could be
that we have a problem with our soft tissue.
And one cause for this problem with a soft tissue
could be the micro-gap. But the question is
what is the reason for this micro cap?
And why we have some implant systems which have
not these problems? So it is not the truth
that every two-piece implant loose
crestal bone in the first year
after prosthetic restoration we can also see over here
and this isn't really interesting
picture because only the
platform switching if not able
to prevent the bone loss. What is the
cause for this micro movements and micro gaps this
are the chewing forces and some measurement of chewing forces
shows us that we have a large and high average of approximately 210
Newtons
if we chew bread it is about 100 Newtons and if we chew
Jelly babies it's more than 250 Newtons
really interesting. So the Jelly babies could
in the future be the killer of our dental implants.
There is
some elastic deformation and some micro gaps
and the question is if the screw really the clue?
so if we found a better binding screw
we solved problem? The best way to show this
or to explain this problem is if we have a look at
3I implant system and original four-millimeter implant
in comparison to a five-millimeter implant and
if we compare this both with
a platform switched situation so we have a five-millimeter
implant diameter with four millimeter
abutment and if the screw would really be the clue
the a micro gap
of the four-millimeter implant should be the same than
the platform switched solution because we have the same binding screw with the
same
initial tension. Now we have a closer look at it
and into over view we can see that there is
and micro-gap inside of the 5-millimeter implant
and if we have a closer look at it we can clearly see
that the is a micro gap
and also there's a micro gap before so the manufacturing tolerances in this
system
are not really perfect. If we
compare this with the 4-mm implant, its clearly to see
that the micro gap increase
and also at the enlargement we can see
that the is really large micro-gap
but if we compare this with a platform switched
solution, we will see
that in the over view its
really hard to find a micro gap but
if we go to the enlargement we can see that there is
a micro-gap but it is really very small
so what is the reason for this
the reason for this are elastic deformation of the implant components
not only inside of the binding screw
We have a look at the videos again and please don't have
a look to the region where the
micro-gap will occur please have a look to the implant wall at the left side
you would see that too is a really elastic deformation
of the implant wall and this is the reason for the large micro-gap
in comparison to this platform whiched situation and
don't have a look to the micro gap please have a look
to the implant wall on the right side and you will see
that there is no or only a small elastic deformation
So, we can say
the screw is only one part of the clue, we should have a look to the whole system
if you have a perfect binding screw and a bad implant
we have solved nothing
So we have set chewing forces and
one without are the elastic deformation
and the micro movements. But the elastic deformation
occurs some shear forces between implant and the bone
and this we could proof with this Camloc implant system
and to simulate and bone loss of three millimeters
and if we loaded you can see the elastic deformation
of the implant wall it is large and if we
simulate no bone loss it's clearly to see
that elastic deformation decreases
again for a better understanding a large
elastic deformation and a small
elastic deformation. So...
if we think about this
the surrounding bone should
stabilize the titanium implant
So its logical that the crestal bone
get really high stress peaks when we load it
so this could also be a reason for the bone loss
but what is a consequence
of these micro movements one consequence is
micro gap and in my opinion and micro pump defect
If we have a look at this example we can feel really a large
micro gap and if we have a look at the slow motion
you can see that we've
simulate the cycles
region at a forty fold slow motion at 200 N
we will see that an actual force verctors
is formed so the connection moves a little bit down and when the
force vector tilts to the left side or turns to the left side
the complete interface moves side ways
and the micro gap we will see is in a
in an area of 36 microns
and I'll think about when this occurs once a day
week by week day by day and month by month
what will he the result? The result will be
that inner interface will be filled
with fluids and bacteria. To proof this
we designed a special gingiva made from a sillicone
and we have a special channel for radio opaque material
and if we have a closer look at it and we stopped
to load it you can clearly see
the to hole fluid will be sucked inside
it's not so good to see with this radio opaque material
so we used better material
and now it's really easy to see that everything will be sucked inside
and now ladies and gentlemen, please remember the good old days
when you were a little child. Remember those rainy days
when you and your friend nothing found thrilling than
put on your rubber boots going outside and
jumping from paddle to paddle. Until one of these
padles was too deep and on the muddy water comes inside of your
rubber boots and
the way home was one squishy step after the other
and it looks a little bit similar what we see here
but you have an advantage when you were at home
you put off your rubber boots and dry your feet and everything was okay
but you patience cannot remove the abutment every day
to try and clean it so the result
looks perhaps like this we have really terrible
substances at these abutments
with a terrible smile and
try it if you use flat to flat interfaces
remove the abutments after one year or two years
and smell the smell... it's really terrible
this will not occur if you use conical interfaces
based on the fact that we have no micro gap inside
so if we load it the Astra tech system
it looks like virtual one piece implant
and also the detailed recording
whick show that their is no micro gap inside
and this is based on a good manufacturing tolerances
and a good dimension or the design of the
conical interface the same with the Ankylos system
we also see no micro gaps inside
but there are some researches
which wants to tell of the two is no micro gap inside
or we will not see the micro gap based on the method
but if we have a look at this Bicon system
I'm just Bicon interface we can see below
there is a micro cap but the interesting thing is
if we loaded with 200 N
the micro gap didn't change so there is no
micro movement inside
and the is the cheap copy of the Bicon system
and we can see for is a micro gap
of the interface
and also with this Straumann Sync Octa
components brand new, there are
micro gaps inside of the on it the conical interface so
if the is a micro gap inside we will
see the micro cap also with a solid abutment
we can see the micro-gap, so the method
will show us if they're is a micro gap
and if we have good designed solutions
there is no micro gap or see no gap because
there is no micro gap and also
if we've load these Straumann implants
please have a look at this region to the thread
and here to the conical interface
we'll see that their is
a permanent shift. The occlusion is gone
so the best thing is for you, you will tell your patient
he should first chew to the other direction and then to the other
because the occlusion is again into right
position. And also
if we have a closer look to the micro-gap
We see that their is a gap forming inside
of the conical interface. Logical
that we see not such a high contrast
in comparison to the flat to flat interfaces
but we will see
the micro-gap inside of the conical interface
and if we see no for example
at the Astra tech system the logical consequence is
that their is no micro gap inside
So also if we see know micro gap
inside of the conical interfaces, it is logical if we fill it
with radio opaque material that we will see
no micro pump effect, because
there's no micro gap where the radio opaque fluid can
be sucked inside.
for the better understanding what is the basic difference between flat to flat
interfaces and conical interfaces
I have some pictures for you and the main
difference is on flat to flat interface that we have
really horisontal bed stop and we have a clearance fit for better fitting
the main difference to the conical interfaces is
that we have for conical bed stop and before fitting
we have a clearance fit and
after fitting we have a press-fit if
manufacturing tolerances are really perfect
and their difference from a mechanical perspective
if that if we loaded with a horisontal component
that the abutment tilts sideways till it will be stabilized inside
of the implant but then it's too late we've got a micro cap
with a conical interface
we have not a problem because we have no micro gap inside if
we load it, the forces can be transmitted directly from the
abutment to the implant with out
high-stress for the binding screw and there is
a second reason we have the effect of conical self-locking
so if you put your abutments inside of the implant
we decrease the micro-gap and if we screw onto binding screw
these abutments will be
go down inside of the implant and the implant shoulder will be widened a little
bit
the consequence is, that this implant shoulder wants to become closer again
the implant shoulder act as force
for out from the implant with the abutment. And normally we should think
the force from below will be move out the abutment
but this will not occur because the
cone angles are dimensioned that we have
high forces from outside and low force
from below and based on the fact that we have a friction between
there if no problem we have the effect of conical self-locking
you can test it if you screw into binding screw
at a conical interface and you
remove it again you have a friction between the implant and the abutment
and this is a proof that the manufacturing tolerances
are really perfect. What are the
important parameters if we want to the design
a conical interface. The first one is the cone angel
than the length of the conical surface
the tension of the binding screw and
the manufacturing tolerances and this should be
like a perfect system if one of
the parts are not perfect the whole system
will not work and we can
see this from
the bone level implant from Switzerland and
from the first few it looks really very good
but you can see that the
conical interfaces, conical parts are too
small and if we have a look to the video again
and you have a look at this region you can see we have
also a permanent shift inside of this interface
and if we have a look to the detailed recording
we see that it is really a large permanent shift
and we also can see that it starts
at only 100 N that we have
a gap forming. But the interesting thing is
in the upper region at our
conical interface we see that the tension is
so strong that we have no gap forming inside
of the conical interface. But there is a movement inside
because it's logical the abutment
tilts permanent sideway and
so we have abrasion inside of this conical interface
and one problem could be we have titanium
particles inside and we destroy
the titaium oxide surface
the titanium oxide surface has to be built new
and so we have a chemical effect
inside near of the bone
and also there is an interesting literature
from the orthopedic implantology where we can see that
nano and micro particles
which has a size smaller than 10 microns
activates our osteoclasts, so
we will get a bone loss and
so we loaded I'm two hundred thousand cycles
and we put it in them
to SEM analyze and
if we come near to it and have a closer look we see
there are really much abrations inside of this
conical interface. And if we have a closer look
we see that it is this not only one particle
but a really much particles and
now we change the mode of the SEM, goes a little bit
closer to it and we see its not one or two, it is 100000 or million particles
which are smaller than one micron
so the can pass the soft tissue
without a problem and I think we will find these particles
after some years everywhere in our body and
also if we come closer we can see that there are particles
which are smaller than 100 nanometers
so we can say that is perfect nano-technology
made from Switzerland. But I don't think
that the cells really will love these particles
so we could get a problem with the bone loss
So let's have at least a look for the reasons of crestal bone loss
and we will see that two reasons are not
only the micro movements
they could come from the surgeon or from the soft tissue
inflammation and also
from the biomechanics or something we didn't know in the moment
and something we know in some years
but if you have a problem with one of these factors
you will get a bone loss. You have to prevent
everything. So for preventing
the system based bone loss you
should use an interface which is free for micro movement
free from micro pump effects and free
from abrations. And if you want
to solve such situations
which these soft tissue
results, you should use the conical interface
the most of the Xray videos you can download from our
website from the University of Frankfurt
and I thank you for your kind attention.