Between Harvard and UPenn, I'd have to say that Penn is a better all around dental school than Harvard. You get a better clinical experience at Penn, the clinics are WAY bigger and were really busy. BUT...I think Harvard will provide you with every opportunity you want. Their match rate is disgusting
Even though the Ivy name doesn't mean that these schools are the best in the dental world, I'd have to say that these are still two of the top schools in the US.
Now even though I'm saying Penn is a better dental school overall, IMHO, I'd still go to Harvard over Penn for a couple of reasons. Harvard is cheaper. Boston is amazing. You get to live at Vandy for 4 years if you want and it doesn't seem like it sucks as much as Penn student housing. And the main reason, you get to do whatever the HELL you want if you go to Harvard. Pretty sweet. But, if I was going to hire someone after 4 years, I'd pick a Penn grad hands down because they'd be more prepared and they'd still have the capacity to learn like a lot of the Harvard students.