Links get the lowest visibility in the Facebook news feed, while photos, videos, and status updates get the most visibility. This is due to the Facebook algorithm, which determines what shows up in the news feed. Top priority is given to videos and photos.
As a general rule only about 6% of the people who have “liked” your dental page will get your office Facebook postings on their news feed unless you pay to “boost” the post. You can also pay to generate likes. However paid likes are not at all likely to be a patient or even a potential patient. In fact there are even such a thing as “click farms” that do nothing but like various pages when a business contracts to buy likes.