Building Cusps with Composite Resin by Dr Lincoln Harris

Building Cusps with Composite Resin by Dr Lincoln Harris

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Speaker: Occasionally we have teeth that are missing
a cusp Speaker: and we need to cap the cusp but they can’t
afford a crown Speaker: or an inlay. Speaker: So there’s times when we have to build them in
composite. Speaker: In this case it’s obviously a fake case
that’s obviously extracted teeth put Speaker: into silicone Speaker: and that’s why there’s an upper and a lower
tooth next to each other. Speaker: I’m using a sectional matrix band even
though it’s the distal Speaker: of the tooth that is missing and I’m just
holding it in place Speaker: with flowable. Speaker: You’ll notice that I use the flat plastic
to hold the band against Speaker: the tooth as I cured the flowable that
holds Speaker: that band in place. Now I’m Speaker: putting a thin layer of flowable over the Speaker: dentine areas and a little bit at Speaker: the distal just so it kind of acts like a
wetting agent. Speaker: Now when I put the paste composite Speaker: and pack it against that sectional matrix Speaker: with the microbrush there will be no
bubbles Speaker: because of the wetting effect of the
flowable Speaker: resin. Speaker: Now I’m holding that probe Speaker: and I’m very carefully looking at the
mesial marginal ridge Speaker: and I’m using the mesial marginal ridge as Speaker: a guide so that when I take everything out
I’ve Speaker: got a little distal marginal ridge that’s
the same height Speaker: as the mesial. Now when we look at Speaker: the tooth I’ve already done the two cusps, Speaker: their the easy ones because it’s an
existing tooth Speaker: structure. So we’re building Speaker: up a cusp on the distal. Speaker: The distal marginal ridge is acting as our Speaker: height guide and so is the mesial Speaker: and the adjacent tooth structure. Speaker: You can see I’ve built basically a Speaker: cone or a pyramid of composite Speaker: and then we push it into the right shape Speaker: with a microbrush. The microbrushes don’t
need to Speaker: be coated. They won’t stick to anything Speaker: and then we use the probe Speaker: and we use the probe Speaker: to take off the excess on the buccal Speaker: and lingual first. So you can see it’s Speaker: taking off the excess there and then we Speaker: lay it on its side and we put the tip down
into Speaker: the fissure area and we angled the Speaker: probe up towards the cusp tip using the Speaker: other cusps as a guideline. Speaker: So basically if you have the fissure of a
tooth at Speaker: the right height and you have the cusp
going up Speaker: at the right angle then you’ll be very very
close to Speaker: the right occlusal height. Speaker: So it’s just one of those little secrets Speaker: with composite resin that if you put Speaker: the fissure in the right place and have the
cusp at the right angle Speaker: then it automatically forms the Speaker: right occlusal height. Speaker: So here you can see I’m doing the other
side once again a Speaker: small drop of flowable then a cone of
composite Speaker: injected using the microbrush Speaker: to form that into a pyramid. Speaker: So cusps are basically just little
pyramids. Speaker: So forming it into a pyramid. Notice that
the point of the Speaker: cusp is not at the edge of the tooth Speaker: but is actually quite some distance in
towards the fissure. Speaker: So it’s not quite halfway between the Speaker: edge of the tooth Speaker: and the fissure. Speaker: Now you can see also that I’m not trying Speaker: to make the cusp smooth. So cusps, Speaker: if you look at teeth they’re not smooth. Speaker: They’ve got lots of ridges. Speaker: The ridge on a cusp tends to go from Speaker: the mesial from the tip Speaker: down mesially if it’s a distal Speaker: cusp and it goes distally if it Speaker: is mesial cusp. Speaker: Just adding a little bit to the mesial cusp
here. The mesial buccal cusp was a Speaker: little bit deficient there on the margin
line. Speaker: So added a little bit of extra. Speaker: Now we’re just forming that buccal fissure Speaker: pattern making sure it’s in the right place Speaker: but basically put the fissure in the right
place Speaker: first and then you can put in the final Speaker: anatomy. Just using kind of a Speaker: tapping or a pressing motion. Speaker: You can’t drag composite so you Speaker: have to tap it. Maybe I’ve heard Speaker: Jason Smithson and call it a wood pecking
motion. Speaker: Now the distal marginal ridge Speaker: is a little bit too sharp. Speaker: It needs that nice roll Speaker: and marginal ridges are quite tricky. Speaker: Now you can see once again the flowable so
there’s no Speaker: bubbles. Little drop of flowable and then
the paste composite Speaker: over the top. Now first of all just getting Speaker: it into the right position with the
microbrush Speaker: and then we’re using the probe. Speaker: We’re getting it at the right height
compared to Speaker: the mesial and often the marginal ridge has Speaker: a little groove right in the middle. Speaker: So I’m assessing the mesial marginal ridge Speaker: and then copying that heightto the distal
marginal ridge. Speaker: Obviously if you make the distal marginal
ridge much much higher Speaker: than the mesial one when you go check the
occlusion everything Speaker: will be too high Speaker: and you’ll cut it all off. Speaker: Now we have a little bit of a dilemma Speaker: here because every time we squash that
marginal ridge Speaker: down to the right height we then fill in Speaker: the fissure pattern so we’ve got a little
bit of to Speaker: and fro going on here where we squash the
marginal Speaker: ridge down to the right height create that
little Speaker: V shape groove in the Speaker: middle there but then that fills in the
fissure pattern. Speaker: So we’ve got to kind of dig out the fissure
pattern which Speaker: gets rid of some excess composite. Speaker: You can see I’m scraping the excess of Speaker: and then we have to squash it down again Speaker: and then get rid of it. Speaker: Now it certainly does take a little bit of
time to Speaker: form this anatomy doing it this way. Speaker: It takes generally a lot less time doing it Speaker: in the mouth than I find doing it for a
video. Speaker: I think doing it for a video you just get a
lot of performance Speaker: pressure because you know that 10000
dentists are going to watch Speaker: it. Speaker: So the flipside of this Speaker: of course is that if you’re just do a big
flat composite Speaker: then normally you end up with it really
high in the fissure area Speaker: in the middle of the tooth Speaker: and it’s this area that takes the longest
to adjust. Speaker: So if you have the tooth high on a cusp tip Speaker: it takes hardly any time to adjust. To take
a little bit off Speaker: a cusp tip takes next to no time Speaker: but if it’s high in the middle of Speaker: the tooth in the fissure area then it takes Speaker: an enormous amount of time to adjust that Speaker: with a bur unless you just get a massive
coarse Speaker: diamond bur and you just don’t care Speaker: and you just grind the heck out of the
tooth. Speaker: Now this cusp is obviously not quite Speaker: pointy enough Speaker: and the tip of it was a little bit towards
the buccal Speaker: or so I’ve just added a tiny bit more
material so I can move Speaker: the line angle between the occlusal Speaker: and the lingual slightly more towards Speaker: the fissure more towards the middle of the
tooth Speaker: and then doing the same on the other side. Speaker: So sometimes there’s a limit to how high Speaker: a cone you can get the composite to form in
to. Speaker: So you have to add a little bit more on. Speaker: So this one I’ve just added a little tiny
bit more onto the tip. Speaker: Always a drop of flowable first. Speaker: Other people do it differently that’s fine. Speaker: I like a little drop of flowable between
every layer of composite just to act as a Speaker: highly filled wetting agent. Speaker: You can see that I’m starting to develop a
little bit of the ridge Speaker: that runs down the cusp here. Speaker: Okay if you don’t know your anatomy just
guess. Speaker: Okay it really won’t make a lot of
difference to the tooth Speaker: but just starting to guess about the cusp
shapes Speaker: and where the little ridges Speaker: and where the fissure pattern and what
shape the fissure pattern should be Speaker: is. There’s a lot of variation in
individual teeth Speaker: and if you start to just sort of get this
in your Speaker: mind then you’ll find that Speaker: when you start doing ceramics it becomes
easier to Speaker: assess whether your technician has done a
good job. Speaker: Now finally I’m just using a 12 scalpel
blade Speaker: to scrape off the excess. Speaker: In this particular case when you see the
final Speaker: photo there was absolutely no, Speaker: there was no rotary instruments used at
all. Speaker: I actually did this at home where there is
no dental chair. Speaker: So it just goes to show you the sort of
shape Speaker: and form that you can get without actually
using a bur Speaker: at all. Now to get the Speaker: overhang areas done Speaker: with a scalpel it is actually faster Speaker: and as you can see there at the end we’ve
got Speaker: the tooth once it’s had a little bit of
tint Speaker: and a final layer of adhesive placed over
it Speaker: to give it that nice shiny finish. Speaker: Thank you so much for watching. Speaker: If you want to see more videos like this
come to Speaker: the Restorative Implant Practice Excellence
page. Speaker: Thank you so much.

12 comments

  1. Thank you for the reply, I need help in finding a dentist who does this in the states, please let me know if you know any dentist

  2. Now this is great video! Wonderful technique. Especially love the bit about removing the matrix once you've built the interproximal wall so you can clearly define the occlusal anatomy.
    Thanks!

  3. This video made me feel so much better about my problem. My orthodontist is willing to build up my molars to make my teeth look more like teeth. I had an amazing dentist who was willing to do the same thing but she quit at the office she was at. I haven't found a dentist that I trusted yet so that's why my orthodontist said she'll do it. I didn't think anything like this was possible. She told me she would build up my teeth and if I have problems later on then I would maybe have to get some crowns. How long do these usually last? Is it okay to wear with retainers or a night guard and what happens if I have to get them touched up? I have extreme anxiety about loosing anymore tooth structure so that's why orthodontist said she'll try everything she can to help me so I won't have any more anxiety.

  4. Watching this gave me so much hope! Is it possible to apply this to a crown 2nd last top left molar zirconia? My dentist said he could build up the bottom teeth. Was just thinking the crown could be why.

  5. good job good work well thats worth a try as many as it takes …
    but how did you mange to make the instruments not to stuck to the composite ??? and working without etching..?? and couldnt you make an inlay adapte it so y make it more easier ??? or thats not the case ..??

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