You're lucky. The health care reform law doesn't include dental, so that must be either a state law or your mom's insurance company being generous. The company I work for is including dental coverage, but not until 1-1-11.However, as a result of law changes, I was able to go back on my mom's insurance this past year, so I have a dental plan until I turn 26 (which is in April, so I should probably take advantage of it soon).
It's my mom's insurance company. Her dental is part of her overall plan, so I get to take advantage of it for the time being. I only have a select group of dentists I am allowed to use, but it's better than nothing!