Liquid/soft food diet and effect on your teeth

I am now 2 weeks (tomorrow) post Nissen and have been following a liquid/soft food diet and noticing that my teeth feel as though they are coated. I have been brushing 3 times a day, using the tooth harps and mouth wash but they never feel smooth and clean. Has anyone else noticed this?

I have a dentist appointment at the end of this month and rang to ask for a hygiene clean as well and was told I couldn't have one unless the dentist prescribed it, even if I wanted to pay for it - how bizarre!