The statute of limitations in Maryland is generally three years, unless specifically extended by statute, concealment, or tolling due to disability.
If you have been served with a District Court complaint, file your Notice of Intention to Defend promptly (it must be filed within 15 days of service), and allege the defense of statute of limitations. Consult with an attorney if you are confused about the process of defending the potential lawsuit.
However, keep in mind that in Maryland, if you acknowledge that you owe the debt beyond the date when the original dental surgery occurred, then that extends the statute of limitations.
DISCLAIMER: Brandy A. Peeples is licensed to practice law in the State of Maryland. This answer is being provided for informational purposes only and the laws of your jurisdiction may differ. This answer based on general legal principles and is not intended for the purpose of providing specific legal advice or opinions. Under no circumstances does this answer constitute the establishment of an attorney-client relationship. For legal advice relating to your specific situation, I strongly urge you to consult with an attorney in your area. NO COMMUNICATIONS WITH ME ARE TO BE CONSTRUED AS ARISING FROM AN ATTORNEY-CLIENT RELATIONSHIP AND NO ATTORNEY-CLIENT RELATIONSHIP WILL BE ESTABLISHED WITH ME UNLESS I HAVE EXPRESSLY AGREED TO UNDERTAKE YOUR REPRESENTATION, WHICH INCLUDES THE EXECUTION OF A WRITTEN AGREEMENT OF RETAINER.