How is a crown prep done
Dental Crown Explained | Anterior Crown Preparation
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what is up guys welcome back to the
channel
it's a beautiful Sunday afternoon here
in San Diego and the purpose of today's
video is to look at things I consider
when designing an anterior crown this is
gonna be a little bit different than my
other videos because I'm gonna keep it
super long format so that you'll be able
to scrub through the footage from the
beginning of the crown preparation all
the way to the impression I think that
provides the most value for those of you
out there that are trying to perfect
their crown preparation designs also I'm
gonna be focusing on how to create
really crispy sharp well-defined margins
how to make your crown preparation very
smooth and how to work efficiently so
that your patient is very happy at the
end of the day my philosophy is that if
you spend a little extra time perfecting
your crown preparation then your
assistant will do a better job with
their temporary crown the laboratory
will do a better job fabricating the
porcelain crown and ultimately when you
cement the crown you'll have really
flush smooth margins that hopefully last
a very long time for the patient so
let's jump right into the video as I was
talking we already started the facial
reduction as well as working a little
bit on the margins of the tooth I like
to combine both of these steps together
because it helps me really perfect that
crispy margin that we're trying to
achieve by the end of the crown
preparation design we also need to have
a discussion about why we chose to do an
anterior crown versus an anterior veneer
when we're weighing our options about
whether to do a veneer or a crown I like
to consider the most important factor
for a veneer which is the amount of
enamel left over after preparing the
tooth as you can see this patient
already has a large buckle composite
that takes up a little bit less than 1/2
of the facial surface of the tooth the
bond strength to that composite resin
versus the bond strength
- pure enamel is much less so ideally we
want to have a lot of enamel on the
facial surface of the tooth for a veneer
to be even more successful and have
strong bonding capabilities also when
you're considering designing a veneer
you have to think about what color
change you're doing if you're trying to
go from a very dark color to a lighter
color veneer meaning if the tooth is
already very dark to begin with then you
have to design the veneer a little bit
more aggressively so after talking about
this with our patient we gave him both
options and he decided that the best
option would be an anterior crown
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now you can notice here that I take a
slow speed round bur that runs on a
slower rpm I start teasing away the
cavity a little bit at a time and I make
sure that I have hard sound to structure
and that all the cavity is completely
removed at this point I like to place a
chord and in typically a place as large
of a chord as possible in this
particular video I believe it's a number
2 chord that wraps around the entire
gums and I place a chord now because of
two reasons number one as I place the
chord the gingiva around the tooth
pushes out of the way and you'd be
surprised how much to structure you'll
see and you're able to prep once you
move that tissue out of the way
sometimes you can get two or even three
millimeters of extra length to the tooth
for added retention this really helps
with teeth that have short clinical
crown links to begin with like the
second molars in the back of the mouth
where you want a little bit of that
Maxiell wall height for added retention
of course if you're bonding your crown
to the tooth you don't need that
retention but I'm still a believer of
mechanical retention to support the
tooth and in order to have a stable
crown for as long as possible I would
mention that some people prefer to pack
two cords meaning a double-0 cord and
then a another chord on top of that to
move the gums out of the way for a
better impression and I actually do
agree with that in this particular case
I only packed one cord and it was enough
for me to achieve a really nice
impression which you'll see at the end
but if you decide to go the other route
you can do that as well now some
dentists do like to use the cavity
preparation as part of the crown design
and I see no fault in that
in this particular case I wanted to fill
the cavity with composite resin so as
you can see here I use I use I believe
clear fill SC protect placed a primer
dried it out place my bonding aid
dried it out pure and then I placed a
little bit of flowable composite to fill
in that void in the tooth is that
absolutely necessary I don't think so
but I wanted to really clean design for
the video so here it is so notice how
I'm really taking my time with this
crown preparation I'm trying not to Nick
the tissue at all because I don't want a
bloody mess and I'm making sure
everything is really smooth
if the crown preparation is entirely
smooth then the dental laboratory has an
easier time fabricating that porcelain
crown and during the cementation
appointment it just slips right in and
you have nice contacts when you have
sharp edges to your crown preparation
that's when dentists and lab technicians
run into problems so I definitely
encourage you to take your time to
smooth and everything out and really
polish the restoration to make it look
as nice as possible so I want to make a
few notes about the final impression I'm
carrying the light body and my assistant
is carrying the heavy body of course we
check the occlusal clearance we try and
the Train them out a couple times to
make sure the patient is biting down in
the right way you'd be surprised how
many times a patient when they're out
there's open this long forget how to
bite on their back teeth and that's not
their fault that's something that you
have to remind them to have have them
bite in the right occlusion when you
have a core packed in there as long as I
have it packed in there it can dry out
and you don't want to lift the court up
when it's dry because when it's really
dry it can tear the tissue and when it
tears the tissue guess what you have a
lot of bleeding and then you have to
control the bleeding with either
astringent
or you have to repack another cord so
make sure to moist in the cord a bit and
then slowly tease it away you can
evaluate if you have any bleeding sites
places stringent in as necessary to dry
it up the best way you can
and then you're gonna use that light
body to go around the tooth in a very
slow manner I like to start the margin
and I slowly work my way to the top and
then you place the tray and have them
bite down
typically the setting time we wait about
five minutes take it out and then your
assistant will finish the provisional
crown so that's all I recorded for you
guys today I hope this helps any of you
out there that are trying to learn
different techniques about crown
preparation design if you have any
questions or comments leave it down
below please like subscribe support the
channel and you know one note I'm
thinking about doing a series a ten part
video series where my wife and I go into
how to design a practice we're in the
process right now of expanding our
office into a new space we've made
decisions about whether to lease or buy
and a lot of other business decisions
that please let me know if that's
something you're interested and
listening to and we'll get to work
making a video series on that thank you
so much for tuning in I hope you enjoyed
it and I'll see you for the next one
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