Micro Sample HandlingAuthor: Dave Date: 02.08.26 - 10:44am Ok, so i sent a sample off for SEM imaging (dont ask). The samples were pretty small and hard to manipulate safely. One time i tried handling them on a black foam backing in a glass petri dish and one almost launched into outer space. If you know you know. We've all been here before: 
So I need a way to contain the pieces while i rearranged them on the carbon double sided tape. $12 later and we have this beauty lol 
Its crude af, but i am sure it will avert any potential disasters! I still need to sand the top flat, and maybe make a proper holder in the bottom for the SEM stub. More ports would be welcome. I was working at max angle where the tool was hitting the port sides but it worked. I was working using the boom scope looking down through the top. Tweezers stabilizing the SEM stub, pokey thing rearranging samples. Slight shit show but workable. In other news, I now own a Metallurgical Microscope (AmScope ME580 40-800X) lol. After paying $800 for SEM imaging it was easy to justify. 
Ok, I will add one more. I think that the following represents partially occluded dentin tubules in sclerotic dentin after a 2yr retention period. I made it into a gif as i advanced the focal plane into the sample. I tried to get a video capture but the 8mp camera but could not get the settings right, so these were taken through the eye piece overlaid & cropped. This was at 500x with polarizers. The second is at 160x. The remainder of the sample looks like a stalactite with heavy mineralization I will try to polish it and get a better area. This area was under what i think was a necrotic tissue cap so semi protected until that came off. They all follow the same path and are the same size. You cant quite tell from the images but the paths take a lazy helical path which apparently how they actually go. I never could have guessed that fact which is a good sign. I have a calibration slide and reticular eyepiece coming so I can measure size and density. I will update the post when i get more deets.   
I did try creating a stacked image with helicon trial, but honestly the gif gives us a depth perception it cant. Watching the tunnels wiggle and lose focus is information. The gifs do not do justice to what you see through the eyepiece... bleh (technical term) 
Ok, so I got in my reticular eyepiece. here is my calibration at 500x. I also calibrated the line width as a short cut for sub measurement.   The bounding box I drew I estimate 6 tubules / 784 μm² = 0.00765 tubules/μm² -> 7,650 tubules per square millimeter. Which is low...but..this is sclerotic dentin where we expect occluded tubules. Really I would have to build a table of calcs based on different focal planes, magnifications and locations. I was going to try to use the line width trick to get tubule diameter, but this shot is not focused on the surface, which means diameters are not measurable here. Anyway..this initial number is reasonable for what we believe were looking at. Just that sclerotic dentin sucks to identify in this manner since it was a war zone..pfft Initially from the SEM, I thought the following may have represented tubules, however the size and density do not fit and look more like bacterial artifacts which are still interesting... 
I guess I'll round out the story at this point..2 years ago I had a burr extraction of #24. There was a 3+ month fistula and a red spot which persisted for the full two years. I have no idea what came out while the fistula was active, I didnt know to watch. As I learned more I kept an eye on the red spot, and eventually this shard came out. (You can find the magnification locations here) 
Ok, so minor update 3.1.26... got my ebay puppy teeth!, drilled a cavity in a wood block and hot glued them in then sectioned one a diamond dremel wheel. The other i hot glued flat and surfaced the top off with a dremel diamond burr. I mounted this one with epoxy on a wood block and lapped it flat going up to 12000 grit. I will go finer but this is what I have for now. I can see the same white whispy structures in my known sample. Cool beans. Also i noticed when repositioning my exfoilated sample, the steel tip probe left some smear and deformation similar to wax. dentin is very soft! I was also able to replicate this exactly the same with the known puppy tooth sample. So basically my exfoilated shard is dentin. Last image is the tubules stained with india ink with a vacuum chamber. Next comes fuchsine and then silver nitrate.   
Now I am just doing what nerds do... If you are a research who finds this while googling sclerotic dentin feel free to contact me for the full SEM image set and detailed specimen provenance. I still have questions I am working on myself. Comments: (3)On 02.08.26 - 10:58am dave wrote:
On 02.12.26 - 10:44am Dave wrote:
On 02.17.26 - 10:15am Dave wrote:
|
About Me More Blogs Main Site
|
||||||||||||||||||||||||||
