hello welcome to chairside live I'm Megan strong and I'm Will Smith registered dental
assistant here at gladwell dental and we're so happy you're with us today because dr. Qi he's
restoring a fractured all ceramic restoration on number 14 with Brooke sir now that's right he's
going through the clinical steps of preparation and delivery today we're gonna see him prepare
design mill and fabricate a Brookshire nail crown in just under one hour let's see it in
this episode I'm gonna dive into more detail for the same day Brooke sir crown case I introduced
in episode 255 to recap my patient presented with a fractured all ceramic restoration on his upper
left first molar the existing restoration is a crown lay which is a more conservative full
cusp of coverage restoration without as much axial coverage like a full coverage crown this
has become a popular restorative option among the chairside cad/cam community since we're
able to restore large non retentive preparations immediately this was a really great restoration
that served the patient for quite a while with most all ceramic restorations we can pretty much
assume they're bonded in adhesively so often requiring multiple slots to reach the prep
beneath here I'm using a zur cater burr from gold and dental to create three slots through
the restoration the burs designed for removing zirconia but also works really well with other
strong glass based ceramics after the slots are created I use a Christensen crown removal tool
to then separate the sections off the tooth there's usually one remaining piece that if
small enough it can be separated by gently running the burr along the interface by air drawing the
tooth you can also get a better visualization of any remaining cement which I prefer removing to
have a fresh tooth surface to cement to anytime we're replacing an old restoration it's time to
evaluate what defects exists to see if it will be included in the external outline of our prep
since there's a large buckle-up fraction I decide to prep the buccal to include that in the final
restoration the cool thing is the lesion created a nice deep one millimeter chamfered margin which
is my preferred margin design for any CAD cam restoration I'm using a coarse grit 856 oh one
for round ended tapered diamond bur to reduce the buccal to a depth that blends in with the
up fraction and also to connect to the finish line of the original prep the round ended bur
helps establish a rounded internal angle at the gingival axial wall transition on the occlusal
I do want to establish an appropriate amount of clearance but first I blend in some of the
depth cuts I made during the initial sectioning of that defective restoration since it's nearly
impossible to visually tell how much reduction or clearance we have on our prep I like to use a
curved flexible clearance tab in a one and a half millimeter thickness with the tab position over
the prep and the patient biting together I try slide and tab out if there's any resistance I'll
need to reduce more to determine where to reduce we add a piece of articulating paper between the
clearance tab and the prep to mark on the tooth where we're underprepared I like shooting for one
and a half millimeters of clearance since it will provide room to design an anatomically correct
restoration with adequate material thickness for strength when I'm finished making the bulk
reduction on the axial and occlusal surfaces I try to round over the internal line angles with
a football or round bur to minimize any internal stress along our restoration I also like to run a
pareo probe along the margins to evaluate the reduction in smoothness the probe provides a
great tactile feedback of these two aspects along this critical area of our preparation
if I lose an apical stop I know I haven't created at least half a millimeter of reduction and if I
feel any roughness I'll want to smooth these areas to establish a good seal between the restoration
and the prep on the mesial area the translucent roof of the pulp chamber is visible since we're
close I'll place a thin layer of Vichy Braun glass ionomer for our added protection glass
ionomer does chemically bond to tooth structure but I like to do a quick acid rinse to remove the
smear layer in this case I used 37% phosphoric acid for 5 seconds and rinse that off I'll then
place a 1-minute application of guma desensitizer suction off any excess then apply the glass
ionomer the final prep resembles a full-coverage crown on the buccal but I actually didn't prep
much more away from the original lingual margin position I tried preserving as much healthy tooth
structure as possible and with the chairside mill it does allow me to restore indirect restorations
immediately without necessarily prepping for a provisional an area that I should have actually
prepared more way on was at the distal margin ideally we should create half a millimeter of
separation between the prep and adjacent teeth for digital impressions less than half a millimeter
of separation increases the chance of bridging on the digital model and with conventional PVS
impressions there could also be a distortion tear or void in the material from that area being too
thin so make sure there's adequate separation to make life easier on yourself or on your
technicians speaking of making things easier on technicians if your margins are subjuntivo
some sort of gingival retraction must be used otherwise margin identification at best becomes a
guesstimate here I'm using a single-core technique with the size one along the buccal and a size two
on the mesial I allow the courts to sit for at least five minutes then gently pull the cords
while they're wet right before I take the digital impression I wet the cords and remove them gently
to reduce the likelihood of any bleeding once I verify that I've achieved the appropriate amount
of retraction I dry the area well then begin the digital impression using the eye tarot
element the first scan is a high-resolution scan of the preparation for the prep upper and lower
quadrant scans I begin each scan on the occlusal then rotate to the lingual and buccal to capture
those contours and areas beneath the height of contours with the scanner resting on the adjacent
teeth I focus on the screen where I can see the live view of what the camera sees on the lower
left to help stay centered on the teeth and I also observe the digital model build in the middle as
I move the camera along the different surfaces once the digital impression is captured of the
prep opposing and bite the data is transferred to the lab of my choice in this case it's sent to my
Glidewell in office design station the first step in the fast design software is margin marking the
margin is designated by the red dotted line I rotate the model around to ensure the line is
marked correctly if the prep has a sharp finish line and adequate retraction in sub gingival
areas this step should be completed very quickly once the margins are set the software generates
a functional and aesthetic design that fits the restorative space clinicians can easily control
any area of the design to fit the patient's needs prior to sending the design to the mill I check
and dial in the proximal and occlusal contacts the values that work best for my system incredibly the
entire design process typically takes less than three minutes I'm so grateful to the 60 software
developers that dedicated over 700 man to create this very easy to use design software when the
design is complete how does a 35-minute turnaround time for a fully centered Bruck circ round sound
it kind of is unbelievable and shouldn't even be possible but I'm amazed every time after I
lock up bruxton l block into my fast mill I get a perfect fitting Bruck sur crown that's
ready to be delivered on the Millbrook sir I snapped the crown at the thinnest point of the
sprue and smooth the residual down with a fine grit red stripe diamond burr at this point I'll
seat the crown and check the proximal contacts since I found a contact value on the software
that works for me I normally have very little to no need to make adjustments to these areas
after evaluating the margins with an explorer and a bitewing radiograph i'll check the bite
for any heavy contacts when making adjustments to lab or chair aside Bruck sir we recommend using
fine grit diamonds to limit the amount of surface roughness following any adjustments polishing the
restoration is recommended to ensure the adjusted surfaces are as smooth as possible here I'm using
the ASAP polishing kit by clinicians choice that is designed to work really well on any restorative
material these polishing wheels will be included in the new brookster polishing kit that I'll
detail in a future episode prior to delivering the crown I scrub a thin layer of glue my desensitizer
on the prep and allow it to sit for at least a minute the solution will help disinfect the
tooth and reduce the chances of post-operative sensitivity at this point to deliver the crown any
conventional cement or resin cement of your choice may be used with this Bruck Surnow material for
this delivery we're using three M's resin-modified glass ionomer rely excluding plus it's very easy
to use with a pretty quick cleanup after the crown is cemented it's always a good idea to check the
occlusal contacts again and there you have it zero compromise for an immediate Brooks crown
using the Glidewell and office solution if you'd like to learn more please visit Gladwell dot IO
or Glidewell dental comm I look forward to sharing more of the powerful ways we can use the system in
future episodes thanks for tuning in back to you Meghan and well well thank you so much for that
doctor team and if you'd like more information on the glide well do in office solution you can head
to Clyde wolf dot IO but that wraps it up for today's episode so on behalf of everyone here
at global dental thank you so much for watching and we'll meet you right back here next time
you