We live in an increasingly mobile age. Imagine one of your satisfied patients meeting a friend at Starbucks. Your patient says I have a wonderful dentist you should go see him. Let me show you his office. And your patient whips out a smart phone and brings up your web page.
Two questions: Do you have a web page? Ok now how will it look on a smart phone?
Generally standard web pages do not render well on a mobile device. You need to have a mobile version to be most effective. The demo video below is from TNT Dental and shows how a well designed mobile site will function.