3. Negative SEO.
Used to be that a clever Webmaster could manipulate the metatags and stuff the home page with keywords and the site would rank well, producing new patient traffic. More recently there was a trend by some SEO consultants to secure dodgy backlinks from questionable websites that had nothing to do with dentistry.
Search engines have wised up. Not only do these strategies no longer work, they actually work against you, giving your domain a digital "black eye."
The technical term is called backlink pruning. When we take on a client whose website has been relegated to a bad neighborhood, we recommend their site undergo backlink pruning by a qualified individual before our work can begin.