You may want to check out this site's info on HPV (if you haven't):http://www.ashastd.org/hpv/hpv_learn.cfm
As for clearance of HPV, from what I've read, dr's/medical experts have varying opinions on it. Some will say, after a certain amount of time, if you no longer show signs (whether it be warts and/or dysplasia), then it's safe to say you no longer carry the virus. Then you'll have others who'll state that's not necessarily true. That your immune system can fight the virus off, causing symptoms to disappear, sure. However, that it can still be in your system dormant. That it is possible, for whatever reason (be it due to stress, illness, change in your body, etc.), it can come back. I've heard a lot of people compare it to like a flu virus. Your immune system eventually fights that off, and you will be fine. That doesn't mean, however, that you can't get the flu again. I'm sure I'm not saying that exactly right, so don't quote me on it.
I've heard some folks clearing it, not showing signs for YEARS. Then suddenly symptoms pop back up. On the other hand, I have read of people clearing the virus, and never having a single problem again. Since there's still so much they've yet to discover about the virus, it sounds like it's hard to say. Again, my personal opinion.