Does your office have a Twitter account and Facebook page? They are free and a great way to connect with patients. They can also be linked together so your posts show up in both places. Even if you do not plan on using it soon, at least create accounts and pages with both so someone else doesn't use your name or office name.
I am in contact with an office in Texas that is using these very effectively and hoping that they will do a webinar with me to discuss how they are doing it and things that have worked for them.
Each Twitter post (tweet) is limited to 140 characters. Yes, that includes spaces and punctuation. Think you could come up with three posts a day with that small amount of information that would be of interest to your patients. It is also acceptable to repost tweets, just don't rerun every week. Don't think you have the time to do it, then let me help you. For the next three days, I want you to write three posts limited to 140 characters on a piece of paper that you think would interest your patients. Is it someone's birthday or anniversary? Are you running a promotion? Want to remind patients about year end? They don't all have to be dental related. You can write about the weather, a local fund raiser, or items of interest. It is OK to show you are human (you are, right?). I would not have someone ghost write it for you, but you could have staff post items that are clearly from them as well.
I wrote this here and I will use parts of it on Facebook and Twitter.
You can advertise your Twitter and Facebook pages on appointment cards, your web site, and on signs in the office. Do it, it is worth the expense (it is free, remember?).