Earlier quoted context omitted.
This is what you should do: Fire-up Excel and develop a financial model for providing dental insurance to a million people. On another tab, develop a financial model for providing mid-range health insurance to a million people. Finally, develop a financial model for providing automobile insurance to a million people. This will answer all your questions.
Perhaps you'd like to enlighten those of us who are not experts in developing financial models for insurance scenarios?
Probably as someone else mentioned, dental insurance is expensive because even though routine dental work is cheaper than getting cancer / breaking a bone, it happens 100% of the time.