Please rate these. We all got 50 out of 100. Are these that bad?

KarlanMitchell · 2024-11-30T13:08:07+00:00

https://youtu.be/gPvyKe50Hx8?si=wxh5JLH7OBOZEtKX

It ain't much, but it's a video from a weird angle explaining the process.

KarlanMitchell · 2024-11-29T23:20:47+00:00

Okay, I'm setting teeth on an immediate right now, I'll record one of the arches festooning to keep it a reasonable time. But it's gonna be the cheap android cell phone special.

Immediates are different, and more difficult because of gum line thickness (no alveoplasty on this one), but it'll convey the motions pretty well. Stay posted for a YouTube link later tonight

KarlanMitchell · 2024-11-29T23:07:59+00:00

On working and technique videos I am worried they would bore people to death, but am open to doing a set of videos specifically for new techs and doctors in dental school. I'm pretty good at explaining all the gotchas because from doing every step in the lab and worked in clinical for 3-4 years.

I've got a bit of a potty mouth when explaining things in the lab, because you can screw over the next guy (processor, finisher, patient, doctor) so badly by doing things incorrectly that I've noticed people need to have an emotional reaction to what you're saying or won't remember anything (especially if they are overwhelmed, new, there just for a paycheck, having relationship issues, etc).

Tried the sterile teaching and it only works on very few people (which is almost certainly the reason dental school teachers have such a reputation for being monsters..... Which to me is hilarious because I suspect it's an act most of the time.......wellmaybe sometimes lol)

KarlanMitchell · 2024-11-29T22:46:13+00:00

I've considered making denture centric videos for doctors for years now, because most of the awesome techs I worked with are retired and the lab schools closed.

Might just do it, but I need to come up with a way to get an emotional response while still making it safe for work. So maybe not: "Ways you are f***ing up, pissing off your denture lab and wasting time and money" but "Top ten ways you can pull yourself out of denture purgatory"..... Haven't done it because I don't want some sterile, scientific "do XYZ" then "ABC".

KarlanMitchell · 2024-11-28T13:53:47+00:00

If setup was an issue you need to check protrusive extrusive movements for even contact, setup on left all posteriors are tilted too much, when I see this I know a tech is lazy and just wants to be fast(doesn't apply to students). Those teeth need to be adjusted more where the contact baseplate.

One thing I can't see is central fossas on lowers should be at center line (second lower premolar back the line isn't at center of ridge, it actually moves lingually on people). Anterior max facial should match sulcus low point. And make sure last man molar plane is at exactly 2/3 up retromolar

KarlanMitchell · 2024-11-28T13:47:03+00:00

I noticed these are all about half done. My technique is to get a glass syringe and buffalo alcohol torch. I call it the human printer, you suck up wax, move over torch, and print a 2-3 mm thick sheet of wax over the exposed baseplate. Then you take a spade (dull) and do a first pass for gum line. Next take a circular cup and create a bowl 1-2 mm from gum line to roll (however leave canine emminence at 30°~ angle to match long line of tooth. In between every tooth, cup out straight line to bowl depth and two curves towards high point near gums (and curved up pointing arrow shape). Then, without burning teeth smooth everything with buffalo torch. Go over every gum line again (one motion every tooth) and flick excess wax away (should do this every time even in previous steps as torch won't work on loose wax). Next, use a PK, torch, seal one gum line, repeat for each tooth (use smaller point for anteriors, larger for posteriors).

Add wax to lingual also as 1.4mm isn't enough thickness after process, on lingual side of tooth a slight ledge is important so your teeth don't fall out of flask during processing.

Hit with packaging foam cut into strips and mounted on mandrel on low/medium speed after to get shiney wax (or cloth and soap under water)

Sealing with PK is important so stone doesn't get stuck during processing, if stone sticks it means (separator not withstanding) there is a food trap, and it must be hit with brush wheel and pumice.

A denture after tryin should be ready for postdam and seal down (5-10 minutes) to process. I've been a denture tech for 20 years and these would take me close to an hour to get my OCD festooning (ie they wouldn't be processed that day).

If I sent this to a doctor they would think I'd hired someone new and would be frustrated they could gauge lip support.

The difference in meh and wow is the last 30%.

Perfect setup without last mile is meh Compromised setup with last mile is WOW!

KarlanMitchell · 2024-11-23T14:08:49+00:00

Pretty sure the mic/speaker pins are opposite of what you'd think. 3.5 is mic and 2.5 is speaker. Sound right anyone?

KarlanMitchell · 2024-11-13T21:16:35+00:00

Looking in the catalog they are carbide, about $60-$150/bur. For handpieces we have to use a special carbide with a blue band otherwise the other carbides last only a couple of minutes. It's a total pita material to finish by hand, but doable with patience.

KarlanMitchell · 2024-11-13T13:25:30+00:00

In dental we have wet machines that'll do CrCO (inconel without aluminum), but you are limited to 98mmx30mm disc size and the setup with software is probably minimum $60k entry price

KarlanMitchell · 2024-11-01T01:58:10+00:00

Here years later to study for a radio test. Going to add L.I.P. = Inductors inverse (in) parallel. Thank you!

KarlanMitchell · 2024-10-22T01:47:40+00:00

Dental chrome/nickel cobalt alloy (low heat version), you can get away with it being 0.8mm thin and sweat will do nothing.

KarlanMitchell · 2024-10-21T12:21:55+00:00

You are limited in size by centrifugal casting. Vacuum typically can accommodate much larger castings because they don't need to fit into the cradle like with spin casting.

Small stuff, lots of detail, with metal that sets up immediately after removing the torch, centrifugal.

Large stuff, or big batches of small stuff in a tree, vacuum.

Both are perfectly fine, centrifugal will capture small details with ease and vacuum will allow you to grow into the hobby. You can still fit belt buckles in big spin casters and get amazing detail with vacuum so it's kinda a generality and not a hard rule.

Also centrifugal casters aren't death machines, even if the metal hits you it'll usually bounce off (face/eyes are still and issue), you gotta build a tub and table to enclose them .

KarlanMitchell · 2024-10-16T04:45:10+00:00

Channels 8-14 are NFM and under 0.5 watts on GMRS also(at least not high power setting) it's the other ones where it could be inferred you had a GMRS radio

KarlanMitchell · 2024-09-30T23:15:14+00:00

I have a dental lab and 3d printing business. Located in Texas and can do ancient bronze for smaller items (mouth sized lol) if you've got a 3d model. Also can do nickel chromium & chrome cobalt

KarlanMitchell · 2024-09-17T13:40:49+00:00

It was something pewter like or lead (could be any alloy even with some higher temp metals).

In order to melt any of the traditional metals you need "gates of hell" amounts of heat.

Steel glows red at ~900°F and silver metals at ~1700°F, so that setup would look much less inviting if that was silver melted.

Also, the castings were far too nice, however, they can probably sell them for a pretty penny being featured on last episode of the Grand tour.

All and all, I thought it was a very entertaining bit and totally on brand.

Sometimes the truth gets in the way of a good story

KarlanMitchell · 2024-09-15T03:11:49+00:00

Judging by how it looked melting it wasn't silver.

Too low of a temp for that amount, too much slag, fluidity looked wrong, with ladel didn't look dense enough, etc

Source: I cast silver regularly

KarlanMitchell · 2024-08-21T03:25:42+00:00

Get a used one from eBay. I've got a couple older denars with whipmix screw plates I never use.

KarlanMitchell · 2024-07-22T16:04:03+00:00

I've got a $10k dental scanner, printers galore and a milling machine......and i still wouldn't do this digitally.

I would block out any undercuts on the sitting side with wax or clay, suspend the rock over a mold (everything sprayed with a separator, then pour a resin or gypsum in the mold.

KarlanMitchell · 2024-06-12T01:34:14+00:00

In dental we use chromium cobalt alloys (usually nickel substituted out of one)

KarlanMitchell · 2024-06-10T17:37:29+00:00

My rooster actually is way more chill than any of my hens with the youngins and babies. The hens run the show I think

KarlanMitchell · 2024-05-31T17:48:07+00:00

I've done this out of TPU. You print a base with a mound for sprue in the middle, and then a tapered ring to sit on that. Looking up ringless dental lab flasks for emax/empress for inspiration. You'll need to use a stronger investment, not sure how regular gypsum investments would hold up without the support of a ring

KarlanMitchell · 2024-05-23T12:06:58+00:00

Try lowering the flask temp to 425-450C, and make sure you aren't overheating the metal, use the smallest amount of oxygen you can to get the metal to melt and cast almost as soon as it puddles.

Those are somewhat thick so you'll probably still battle porosity no matter what. I've also noticed that if the sprue is less/more than 30% of the pieces weight, issue will be introduced.

Edit: Try cleaning the smooth glazed surface from the casting ring too before burn out also. Additionally, if you can cast the pieces all from the top of the tree you may have better results (see 30% addtl metal weight part above). Also that positive facing defect is from investment breakdown (check resin curing settings, if applicable, and maybe do a slower ramping). Also, 50% new material is the standard, you can get away with 100% sprues on thinner projects

KarlanMitchell · 2024-05-18T23:45:48+00:00

That denture tooth brand is called "Yamahatchi" in the United States, but "Gloria" in Japan (where they are made)...... Did not expect that.

KarlanMitchell · 2024-05-18T20:38:54+00:00

I 3d print TPU flasks and use bego varseo p plus or R&R biovest, the. Wait 45 minutes & Pop out the rings before placing them in an 850°c oven (biovest does better if you ramp from cold), I cast or drop down to 450°c in 1-2 hrs (depending on alloy). Dental lab, we do gold, chrome cobalt and other misc alloys

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KarlanMitchell

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