SEDATION From the website of the BC Dental Society
At the most basic level a local anesthetic is used to prevent pain. Applied directly to the treatment site, used on its own it will not alter consciousness. Sedation in conjunction with anesthetic medications is used to relieve pain or to relax and calm a patient in preparation for a dental procedure.
The most common form of sedation in dentistry is minimal sedation, such as Ativan, in conjunction with other medications to temporarily increase its effectiveness. It may cause a little drowsiness. Ask about Smileworks non-medical relaxation techniques.