What do I say about why I left my last job?

I have an interview next week and I am unsure how to explain why I left my last job as a dental hygienist. I am in Madison, in case local advice matters. I do not want to blame the company. Do they ask follow-ups?

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.