FOR IMMEDIATE RELEASE:
AMERICAN DENTAL PARTNERS AFFILIATE RECEIVES ACCREDITATION FROM AAAHC

Contacts:  (781) 224-0880, (781) 224-0880
Gregory A. Serrao, Chairman, President and Chief Executive Officer
Ronald M. Levenson, Senior Vice President, Chief Financial Officer and Treasurer

WAKEFIELD, MASSACHUSETTS - December 16, 1999 - American Dental Partners, Inc. (NASDAQ:ADPI) announced today that its affiliated dental group in Arizona, Associated Dental Care Providers, received accreditation status from the Accreditation Association for Ambulatory Health Care (AAAHC). Associated Dental Care Providers is one of only 7 dental practices in the United States to receive this recognition and is the third American Dental Partners affiliate accredited by AAAHC.

The AAAHC is a private, not for profit organization that is nationally recognized for conducting extensive evaluations of health care provider organizations to ensure the highest quality standards. "We are very excited about Associated Dental Care Providers' completion of the rigorous AAAHC accreditation review. This recognition of clinical excellence is well deserved for Associated Dental Care, which has been providing outstanding care to its patients for over 14 years in the Arizona market under the leadership of Dr. Joe Errante and Dr. Margaret Errante. Since the completion of our affiliation with Associated Dental in January 1998, Dr. Joe Errante, Dr. Margaret Errante and their team have expended tremendous effort to achieve accreditation and this honor is a testimony to their hard work and high quality of care. It's especially remarkable that Associated Dental was able to receive this accreditation in light of the fact that it includes the CIGNA offices which were acquired just this year." said Gregory A. Serrao, Chief Executive Officer.

Ever since the completion of ADP's first affiliation, Park Dental in 1996 (also accredited by AAAHC), the Company has encouraged its affiliates to pursue accreditation with the AAAHC because the Company believes that the accreditation process will help ADP's affiliated dental groups provide the highest levels of care to their patients. Dr. Jesley C. Ruff, Vice President and Chief Professional Officer of ADP, works with the Company's affiliates in the pursuit of accreditation. "We hope that by having our affiliated dental groups be part of a select group of dental practices in the U.S. that have achieved accreditation, 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 groups continue to recruit high quality professionals and enhance relationships with patients, payors and the entire dental community," added Mr. Serrao.

American Dental Partners, Inc. is one of the nation's leading dental practice management companies. As of September 30, 1999, the Company was affiliated with 18 dental group practices and operated 132 dental facilities with more than 1,150 operatories located in Alabama, Arizona, California, Louisiana, Maryland, Minnesota, North Carolina, Oklahoma, Pennsylvania, Texas, Virginia and Wisconsin.

Note: Some of the information in this press release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. The words "believe," "expect," "hope," "anticipate," "project," and similar expressions, among others, identify forward-looking statements. Forward-looking statements speak only as of the date the statement was made. Such forward-looking statements are subject to uncertainties and other factors that could cause actual results to differ materially from those projected, anticipated or implied. Certain factors that might cause such a difference include, among others, the Company's risks associated with its acquisition and affiliation strategy, management of rapid growth, dependence upon affiliated dental groups, dependence upon service agreements, government regulation of the dental industry and year 2000 compliance issues. Additional risks, uncertainties and other factors are set forth in the "Risk Factors" section of the Company's Registration Statement on Form S-4 (File No. 333-56941).