My sleeping tablets make me sleepy?!

Today I went to the Dentist - my dentist is on maternity leave so I had to see a different one. She can't have looked at my mouth for more a minute, I am sure my dentist is more thorough and gets me to lift me tongue up and put it to the side etc. My mum has x-rays done of her teeth, but they didn't x-ray mine. She said everything was OK anyway, and to go back in a year.
I have started some new sleeping tablets - I love the warning label on the box! ;)