Exhibit 99.1

National Dentex Corporation Announces Election of New Member to Board
of Directors

    WAYLAND, Mass.--(BUSINESS WIRE)--Aug. 20, 2004--National Dentex
Corporation (NASDAQ: NADX), one of the largest owner/operators of
dental laboratories in the United States, announced that at its
meeting on August 18, 2004 it had expanded its Board of Directors from
five members to six and elected Mr. Thomas E. Callahan to fill that
new position. Mr. Callahan was also elected to serve as a member of
the Board's Audit Committee. Mr. Callahan's background and record of
accomplishment in senior financial positions, both domestically and
internationally, reflects National Dentex Corporation's continued
efforts to support and strengthen its corporate governance.
    Mr. Callahan has over 40 years of experience in executive
positions within a variety of industries. Most recently, from 1990 to
2001 he served as Senior Vice President and CFO of Welch Foods. During
this tenure he was elected to Welch's Board of Directors.
    Mr. Callahan currently serves on the board of directors of Circor
International, a NYSE listed company. There he is the chairman of its
Compensation Committee and a member of the Audit Committee. He also
serves on the Board of Trustees at Tilton School, a private prep
school in New Hampshire and is a member of their Audit and Governance
Committees, and on the Board of Directors of the Financial Executives
International, Boston Chapter.
    Mr. Callahan is a graduate of the University of New Hampshire
where he majored in Economics and holds a graduate degree in Finance
from Syracuse University.
    National Dentex Corporation serves an active customer base of over
20,000 dentists through dental laboratories located in 29 states.
National Dentex's dental laboratories provide a full range of
custom-made dental prosthetic appliances, including dentures, crowns
and fixed bridges, and other dental specialties.

    This press release contains forward-looking statements within the
meaning of the federal securities laws. The Company's actual results
could be materially different as a result of a number of factors,
including general economic conditions, governmental regulation of
health care, trends in the dental industry towards managed care, and
other risks indicated from time to time in the Company's filings with
the Securities and Exchange Commission.

    CONTACT: National Dentex Corporation
             Richard F. Becker, 508-358-4422