Absolutely. Furthermore, you're going to give yourself a huge bounce-rate if - like the dentist example - you have a single page with no external links.

Google keeps track of how many times users click 'back' from a search result to a search page. Needless to say it's going lower the subsequent rankings that the dentist page receives.

Decreasing the number of pages through clever AJAX use can improve user experience. But it still makes sense to have different chunks of content on different pages, linked together. The SEO implications are a reflection of this.