Well, that's not actually the first thing they're testing:

Now, scientists will see just how similar, because humans will soon undergo a similar trial in September of this year. Lasting 11 months, this study will focus on 30 males between the ages of 30 and 64—each missing at least one tooth. The drug will be administered intravenously to prove its effectiveness and safety, and luckily, no side effects have been reported in previous animal studies.

I'm guessing the idea is to catch teeth that could have developed but never did (hey, I'm missing one that way). Otherwise I'm not sure how they'd control which type and how many show up.

Annoyingly there's no English language link, so it's hard to say. I'm not even clear on what they did with the ferrets.