Physical Danger
Believe it or not, this dental assistant gig comes with its own set of physical hazards.
First, your hands might spend a fair amount of time inside a nervous patient's mouth. While you're removing excess filling cement, or applying a cavity-preventive substance to the patient's choppers, he might be randomly closing his jaws like a "Robot Wars" hammer pulverizes contestants. If you don't have top-notch hand-eye coordination, you'll have some chewed-up fingers by the end of the day.
If you survive that assault, you could be taken down by the varied substances the patient emits while you're working on him. Saliva and blood can slosh around his mouth without warning. If he's battling a cold or respiratory infection, he could unexpectedly hurl a battery of airborne droplets throughout the room when he sneezes.
Either way, you're at risk of contracting an infectious disease. Clearly you don't want that, so you wear a face mask, protective eyewear, and gloves to greatly minimize your risks.
Finally, there's the dreaded x-ray machine, which takes intriguing pictures of your patient's mouth but can subject you to unwanted radiation if you're not careful. You can protect your x-ray patient with a heavy lead apron, but you must follow strict safety procedures to save your own bacon. This is one set of rules you don't want to ignore.