what X-rays of my teeth at the dentist show and why it has to be radioactive and what the heavy apron does
In: Physics
X-ray works by making these tiiiiny little balls really really excited.
They make these special balls have so much energy, they bounce around faster and faster in a box.
This box has a hole so that these little balls fly thru with super duper speed.
The thing is these balls are really tiny. So small that they can go thru you!
Things like teeth are really thick so actually not a lot go thru there. They just bounce off.
But things like your skin is actually quite full of openings that you can’t see.
There’s this special thing that when hit by these balls, they turn black.
So on one side, they shoot these balls and opposite side they receive these balls.
They shoot tons and tons of these!
What comes out is like a drawing. Things that are thick and dense like your teeth come out white because the balls couldn’t get thru! Skin will mostly be black because the ball did go mostly thru.
This gives the dentist a way to look at your teeth that’s inside your body that you can’t actually see.
They give you a apron, it’s made of something called lead.
Lead is special because it’s really dense. Almost no balls can go thru.
The bit of scary things is these balls have so much energy that when it comes zooming thru your body, it can sometimes hurt the little guys in you.
But don’t worry, it’s a very small amount.
But just to be super safe, remember when I said the balls bounce off the teeth?
That apron is there to block those bouncing balls.
The apron is usually there to protect your intimate area. Why? Because the little guys there are like little babies. They are still growing. And growing ones can get more hurt by these fast balls more than the little guys in other parts of your body because they are more grown up.
Xrays are a form of light and are NOT radioactive. All forms of light radiate, but light radiation is not necessarily dangerous. The problem is that xrays are high energy and thus have “ionizing radiation” which means that if radiation occurs in your body the energy can change your molecules. This feature of xrays is an unintended consequence of us using them.
So why do we use xrays? Unlike visible light, they have the energy and property of being able to pass completely through your entire body, but your body tissue can block some of the xrays from passing through depending on what kind of tissue the xray passes through. Bone and teeth block a lot of xrays from passing through, while your gums and tongue block fewer and fluid and abscess block even fewer. A radiologist or dentist can look at the images and see if there are black spots on your teeth crowns to look for cavities or look for dark spots around your teeth roots to see radicular cysts/abscesses which respectively block less xrays than teeth and gums.
So why the heavy apron? The apron contains (typically) lead which blocks a ton of xray particles. We don’t want xrays to scatter from the beam and hit other parts of your body that we are not trying to image because that is risk for no benefit. In actuality, for dentist xrays, xray scatter probably doesn’t matter due to small dose and beam size and the lead aprons are typically stored incorrectly, so they probably don’t do much other than make your feel safe. But lead aprons are still very useful for interventional radiology which deals with much higher and longer xray doses.
Source: Radiologist, not physicist. Sorry if wrong physics terminology is used
The heavy apron is heavy bc it’s storing all those dope radioactive isotopes and delivering them to your body, best to avoid
X-rays have a useful ability to pass through skin and muscle while not being able to pass through bones. By putting your mouth between an x-ray emitter and a special type of film (or sensor), the dentist can see your teeth below your gums.
X-rays fall into the category of “ionizing radiation”. This means they have the potential to rip molecules apart and cause mutations. X-rays at the dentist are so weak that there is very little risk, probably less than spending a sunny day outside without sunscreen. But one area that is especially prone to radiation damage is the reproductive system. The aprons have lead inside them, which absorbs radiation.
X-rays need to be ionizing in order to both be the right frequency to pass through skin and muscle but not bone, while also leaving a recognizable image on the film/sensor.
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