What are the potential ethical considerations of a dentist connecting, that is, "friending," on social media with a patient of record?

What are the potential ethical considerations of a dentist connecting, that is, "friending," on social media with a patient of record? J Am Dent Assoc. 2019 Jun;150(6):562-563 Authors: Howley T PMID: 31133177 [PubMed - in process]
Source: Journal of the American Dental Association - Category: Dentistry Tags: J Am Dent Assoc Source Type: research