debridement of nails, help

When a doctor debrides nails I know it is 11720/11721. What I'm not sure of is do we use both codes if there are more than 5 nails. I know it says 11720 1-5 and 11721 6 or more. But does that mean 11720 and 11721 for maybe 8 nails or just the 11721? Thank you