FOR IMMEDIATE RELEASE:
AMERICAN DENTAL PARTNERS ANNOUNCES AAAHC ACCREDITATIONS

WAKEFIELD, MASSACHUSETTS -- May 3, 2007.
American Dental Partners, Inc. (NASDAQ:ADPI) announced Associated Dental Care Providers (Arizona), ForwardDental (Wisconsin), Longhorn Dental Associates (Texas), Orthodontic Care Specialists (Minnesota) and Western New York Dental Group (New York) have been re-accredited by the Accreditation Association for Ambulatory Health Care ("AAAHC").

American Dental Partners encourages its affiliated practices to pursue AAAHC accreditation as a means to set and maintain measurable quality benchmarks and achieve the highest possible standard of patient care. Dr. Jesley C. Ruff, Senior Vice President and Chief Professional Officer of American Dental Partners, works with the Company's affiliated practices in the pursuit of accreditation. "We hope that by having our affiliated dental groups be part of a select group of dental practices accredited by the AAAHC, American Dental Partners will be at the forefront of promoting clinical excellence in the dental profession," said Dr. Ruff. "While AAAHC accreditation is a rigorous and demanding process, we believe it will help our affiliated dental group practices continue to recruit high quality professionals and enhance relationships with patients and local dental communities," Dr. Ruff added.

The AAAHC is a peer-based, not-for-profit organization that is nationally recognized for conducting extensive evaluations of ambulatory health care organizations to ensure the highest quality standards. More than 2,700 ambulatory health care organizations across the United States are accredited by the AAAHC.

American Dental Partners is one of the nation's leading business partners to dental group practices. The Company is affiliated with 22 dental groups which have 213 dental facilities with approximately 1,958 operatories located in 18 states.

"Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995: With the exception of the historical information contained in this news release, the matters described herein contain "forward-looking" statements that involve risk and uncertainties that may individually or collectively impact the matters herein described, including but not limited to the possibility that we may not realize the benefits expected from our acquisition and affiliation strategy, economic, regulatory and/or other factors outside the control of the Company, which are detailed from time to time in the "Risk Factors" section of the Company's SEC reports, including the annual report on Form 10-K for the year ended December 31, 2006.