Here's some really basic info - most people who suddenly want dental insurance, only want it because they have a lot of work they want done, that they want someone else to pay for.
Insurance companies aren't stupid. They deliberately set up their policies, to handle this. You will RARELY find dental insurance that pays out more than it costs, year after year. Dental insurance has severe coverage caps, and usually won't cover anything more than cleanings and exams the first year.
You will have to see a dentist, and pay them, to see how much this is going to cost you.
Your first step, is to get money. You do that, by working. You do THAT, if you don't want to work for someone else, by putting up fliers, offering to dog sit, house clean, child care, car wash, lawn mow, WHATEVER. Without money, you can't even go to a cheap, local dental school to get super cheap work done. They STILL charge.
Life is NOT going to walk past your house and hand you a billion dollars. You have to go out and get it. Yep, I know your generation is FULL of excuses about why they "can't" go out and do for themselves, what countless generations of 19 year olds have done throughout the centuries, but seriously - you're plan is to spend your entire life in that house while mom's welfare benefits feed and house you until you die? Dude.
Your being "emo" is a luxury that many young adults your age can't afford, because they have to go out and earn the money to pay for their food, electric, and housing. There's nothing special about them; they don't LOVE slaving away at minimum wage to live paycheck to paycheck, but they are doing it anyway.
You seriously need to pull a Nike, and "just do it". Find work, or make work, and then you'll find purpose, and then your life will start coming together. Kids your age have it completely backwards - the "good life" NEVER comes to you - you have to go to IT.