As I was going to St Ives...

As I was going to St. Ives I met a man with seven wives,
Each wife had seven sacks, each sack had seven cats,
Each cat had seven kits: kits, cats, sacks and wives,
How many were going to St. Ives?

I don't know how many wives the dentist has, but the good news is that I get to keep the tooth for another 6 months.