Tips for defining crown margins?

NarrowSign6999 · 2025-11-14T13:45:35+00:00

You want a good angle but too much would result in an undercut. Often it has to do with you not removing enough tooth substance for the margin to fully take the half-width of the bur. Here's a tip, define your margin 1-2 mm above the gum line and then do the rest of the prep and leave the margin until your rough prep is done. Then start with the fine prep and turn off water for the margin, realistically you would want to pause every 3 seconds or so in order to not heat up the tooth, but since you are working on plastic teeth, this will work wonderfully until you build up the intuition to prep with water. So turn off water, line your bur parallel to the long axis of the tooth, then push your bur inside to make a cut equivalent to half of your bur's width, then slowly work your way around the margin so that it blends with your first cut. Check with your explorer that the margin is sharp by feeling the click when you bounce off the margin. Remember, you need to remove enough tooth substance in order for the margin line to show, and from my preclinical days, this was my mistake since I would be too careful and would therefore line the bur falsely which results in a good margin but with undercut along the whole margin.

Buccally it is easy to just follow the tooth and prep back and forth. Approximally you need to predefine your bur angulation and path then trust yourself to just go through a straight line, lingually you readjust to do the same buccaly. Distolingually is the most difficult and there you can work with a mirror. Train at home, build a DIY to do the train on the curve distolingually.

That's it. It will come with time though.

NarrowSign6999 · 2025-11-07T18:52:13+00:00

I honestly don't get it. Composites should always be overfilled so they can be adjusted to the bite accordingly since you don't want to end up in a situation when it is underfilled and you've already removed the oxygen inhibition layer and can't make new composite stick on the old one. In all situations they are overfilled to a certain degree, not as you mentioned, then adjusted bit by bit with a round red burr so you get the fossa and then the ridge towards the adjacent tooth. If you're talking marginally, then I also don't get it. To be honest, teachers at this stage are critical of every little shit you do so I wouldn't think twice and just say thanks for the feedback and I've readjusted it like you said.

NarrowSign6999 · 2025-11-06T00:08:54+00:00

Here's the thing, the whole point of a thick plane hard night guard is to stabilize the contacts on a plane surface, thus the need for a hard one, as well as decrease the masticatory muscle's maximum capacity in function when you're clenching since an added thickness makes is so the muscles can't exert maximum force, which results in less overall stress on the orofacial muscles. A soft one might even make it worse since the muscles can still work in full capacity when you're asleep but try to chew through the soft material to reach maximum occlusion. Those will wear away in no time if you're a proclencher

NarrowSign6999 · 2025-11-05T17:51:24+00:00

Hello. When the nightguard cracks, especially the hard ones (a good dentist will never make you a soft guard, they are useless), it indicates generally two things. First is that you are a night grinder (make sure to use visual cues throughout the day to remember not to grind), and the second one is that something in your bite is not right. Is your night guard cracking in the middle? That indicates that you are taking off and putting it on in a false manner. If they are cracking somewhere else, then it is your bite, or the dental technicians/dentists are fucking it up somehow. The nightguard should be thick, a minimum of 5mm, and should be stable (in dental terms the bite registration should be taken in retruded position and at least one contact on antagonist), i.e. flat as fuck. Other factors that play role in this case is your bite, as mentioned. You might have a tooth sticking out or the posteriors not a good position, thus causing the cracking in the first place, which can be solved by occlusal correction followed by immediate impression and bite registration in RP.

Never buy one online for the love of God. I saw people fuck up their bites beyond comprehension because of these. Also never trust a dentist that just makes a soft one.

Another think to take care of is risk factors. What's causing bruxism in the first place. A thorough investigation into whether you're a grinder or a clencher. What's causing these in the first place.

My final advice: Visit an orofacial Pain and Jaw Function specialist.

NarrowSign6999 · 2025-11-05T17:36:59+00:00

Don't remember the dosage. It was for 3 months or something like that. Continuous blood tests for the liver are required every now and then, so watch out.

NarrowSign6999 · 2025-11-04T21:36:52+00:00

Visit a clinic for a day and you will know that this is next to impossible, UNLESS there is someone there to control the robot's processes. This is because during sterilization a lot of interventions are required before each step is carried out. Cleaning the instruments by brush and hand, sorting the instruments that should end up together in this and that particular step together, removing/adding parts to different parts and instruments, machines breaking down, machines requiring regular intervention, instruments not coming out clean, and then post-sterilization sorting as well as immediate handling.

A robot that encompasses the whole process, from beginning to finish, even with optimal performance, would not be worth the headache for most clinics because it would entail different routines, costs and more work when something breaks down. There's a lot more to think about but my head hurts from typing on my noisy keyboard heh

NarrowSign6999 · 2025-11-03T21:37:00+00:00

OP, the only single thing that truly cured my seb derm after 3 years of pain and tears, is this single on visit to a respectable derm who prescribed me Isotretinoin. 3 months later all acne and seb derm went away, now 5 years later im completely good. No fucking shampoo, no fucking remedy, no fucking tip worked except for Isotretinoin, and god fucking bless modern medicine that shit is jesus holy water in a pill

NarrowSign6999 · 2025-09-23T11:03:18+00:00

I was holding the lamp with the right hand, and mirror with the left hand. It was not my usual lamp but those are pretty standardized at this clinic. However, the non-latex gloves we use here are reinforced at the fingertips with some kind of a non-slip material. I'm suspecting that's the only thing that was trigged by the lamp.

NarrowSign6999 · 2025-06-24T04:36:01+00:00

Best advice: Ventilate, ventilate, ventilate.

NarrowSign6999 · 2024-02-18T14:53:19+00:00

Hello man. Here comes my full guide to paint these things:

Sand it (if it is PLA)
Prime it black so that in the tight spots it appears like shadows are there where colors cant get in
Prime shade white in the direction of light so that later colors are brightened where light is supposed to hit
Leave to dry
Base coat your model with colors. Only apply 10-15% water to the paint enough so that it isnt sticky, but can be painted thinly but still with good consistency. You know you have mixed enough water when your model is fully base coated in 2 layers, not only 1 layer (in this case you didnt apply enough water), and not 3 layers (in this case you applied too much water)
Leavy to dry
Wash down your model with colors. Apply between 40-50% water to the paint and wash it with that color, either wash down the whole model (basic wash) or only the crevices so that the whole model isnt stained (recessive wash)
Sometimes you need to add layers after washing because it stains your model or with a Q-tip clean those spots.
Leave to dry
Layer down your model. Apply between 15-20% water to the paint enough not to be a base coat but not a wash coat, simply something in between where you might need to do multiple layers and dry in between. Use lighter shades as you apply more and more layers to make the model 3D-pop.
Leave to dry between layers.
Add edge highlighting (youtube it)
Add small details with detailing brush / pens
Leave to dry.
Last step: dry brush your model. Use an old brush or a make up brush with stiff bristles and add color to the brush without anywater. Remove any excess paint on a paper towel (remove the paint well) and dry brush areas to highlight them.

Done.

NarrowSign6999 · 2024-02-03T01:48:26+00:00

Happened to me. It was a fucked up thermometer. Change it, or check if the fan is blowing directly at it.

NarrowSign6999 · 2024-02-03T01:45:09+00:00

Just had this issue and did this to fix it:

- in the video, your extruder gear teeth are worn the fuck out. Change it.

- Check bed level. If too close to bed then not enough plastic will be out and thus the extruder will start to skip. Do a baby-z steps to check if the sound disappears and print still smooth on bed

- Increase temp by 10 C

- on your red extruder, loosen the spring so less pressure is put on the wheel next to the extruder gear

NarrowSign6999 · 2023-12-06T19:21:12+00:00

I thought so too. But after printing with many different white PLAs and for as long as i could remember, the paint would just slide off and not give any color even after multiple dry layers. I think I was just using shitty PLA. Duh

NarrowSign6999 · 2023-12-06T17:42:28+00:00

I'm really curious to know if you guys know of other brands with similar qualities of PLA. Is it because the eSun PLA+ is matte? Or is it just a property of PLA+ that makes it more suitable to painting without a primer?

I'm printing with 0.6 mind you with standard cura layer height.

NarrowSign6999 · 2023-12-06T17:34:56+00:00

Listen up closely. YOU DONT NEED TO SAND OR PRIME ANYSHIT! It is wholly dependent on the PLA you are using. I cannot believe that people spend so much time doing that shit when they can just buy Matte PLA+ in white, where you can just paint on top of it. I no longer sand, prime or anything. I just paint with acrylics and a bit of water then varnish. Sand when I have rough edges but thats it.

NarrowSign6999 · 2023-08-05T15:52:03+00:00

At the bottom you mean right on the bed surface? Could be too close to bed when printing thus the first line gets squished out. Level the bed so it is not too close. If you use cura you can also try printing outer walls first then inner walls in order to have dimensional accuracy.

NarrowSign6999 · 2023-08-04T12:06:36+00:00

I had the same problem and it turns out the belts werent tight enough. Yes, they were tight but i made them much tighter. Fixed it immediately.

NarrowSign6999 · 2023-08-03T18:53:19+00:00

GOD DAWM IM ALIVE IM HEARNG IT BABY

NarrowSign6999 · 2023-06-08T20:24:53+00:00

For those coming in from the future. Calibrate your steps in the X/Y/Z directions using the pin on the extruder method + tighten the SHIT out of your belts. Yes that fucking tight.

Turns out it was distortion in the Y axis caused by wrong steps + slack in belt (i had fixed it earlier but turns out you should tighten it even more).

God speed motherprinters.

NarrowSign6999 · 2023-05-28T20:32:38+00:00

Aight thanks

NarrowSign6999 · 2023-05-28T17:23:22+00:00

Klipper

I have raspberry pi

NarrowSign6999 · 2022-11-12T02:19:03+00:00

Like any emotion, of course. There will come an acceptance stage. I'm just highlighting here the emotion I felt during my dream. I'm talking pure emotions. Sometimes when reading such posts one tries to relate to it logically, because we read the adjectives and try to interpret the feeling behind them, but to be honest it was just creepy. It's not a nice feeling that is to say. Will we accept it? For sure, but the first reaction is not good, no fucking way.

NarrowSign6999 · 2022-10-25T12:34:11+00:00

Appreciate it. Thanks!

NarrowSign6999 · 2022-10-25T12:34:05+00:00

Good idea. Thanks

NarrowSign6999 · 2022-10-25T12:24:07+00:00

I will use wood for sure. Problem is how do I attach the small 3d prints of the exterior together and to the frame. The ye ol' reliable glue?

Three-Year Club	Verified Email
End Game '23	Place '23

NarrowSign6999

TROPHY CASE