<PAGE>
 
           As filed with the Securities and Exchange Commission on July 14, 1998
                                                Registration No.333-__________

================================================================================

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549
                           ------------------------
                                        
                                   FORM S-8
                            REGISTRATION STATEMENT
                                   UNDER THE
                            SECURITIES ACT OF 1933


                        AMERICAN DENTAL PARTNERS, INC.
            (Exact name of registrant as specified in its charter)

           Delaware                                       04-3297858
(State or other jurisdiction of                          (IRS Employer 
 Incorporation or organization)                     Identification Number)

                        301 Edgewater Place, Suite 320
                        Wakefield, Massachusetts 01880
              (Address of principal executive offices) (Zip code)

                        American Dental Partners, Inc.
                  Amended and Restated 1996 Stock Option Plan
                           (Full title of the plan)

                  Gregory A. Serrao, Chairman, President and
                            Chief Executive Officer
                        American Dental Partners, Inc.
                        301 Edgewater Place, Suite 320
                        Wakefield, Massachusetts 01880
                                (781) 224-0880
                             (781) 224-4216 (fax)
                (Name, address and telephone number, including
                       area code, of agent for service)


                        CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
========================================================================================================
                                                           Proposed        Proposed
                                                            maximum        maximum
                                           Amount          offering       aggregate       Amount of
Title of securities                        to be           price per       offering      registration
to be registered                       registered(1)       share(2)        price(2)          fee
--------------------------------------------------------------------------------------------------------
<S>                                  <C>                 <C>            <C>             <C>
Common Stock, $0.01 par value                973,246            $14.06     $13,683,839          $4,037
========================================================================================================
</TABLE>

(1)  Pursuant to Rule 416(a) under the Securities Act of 1933, as amended, this
     Registration Statement also includes an indeterminable number of additional
     shares of Common Stock that may become issuable pursuant to antidilution
     adjustment provisions of the Plan.

(2)  Estimated solely for the purpose of calculating the registration fee in
     accordance with Rules 457(h)(1) and 457(c) under the Securities Act of
     1933, as amended, on the basis of the average of the high and low sale
     prices of the Registrant's Common Stock on the Nasdaq National Market
     System on July 7, 1998.
<PAGE>
 
                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.      INCORPORATION OF DOCUMENTS BY REFERENCE.

     The following documents are incorporated by reference in this Registration
Statement:

(a)       The prospectus filed with the Securities and Exchange Commission on
          April 16, 1998, pursuant to Rule 424(b)(4) under the Securities Act of
          1933, as amended (the "Securities Act"), with respect to the
          Registrant's Registration Statement on Form S-1, File No. 333-39981
          (the "S-1");

(b)       The Registrant's Quarterly Report on Form 10-Q filed with the
          Securities and Exchange Commission on May 11, 1998, and the
          Registrant's Current Report on Form 8-K filed with  the Securities and
          Exchange Commission on June 11, 1998; and

(c)       The description of the Registrant's shares of Common Stock which is
          contained in the Registrant's Registration Statement filed under
          Section 12 of the Securities Exchange Act of 1934, as amended (the
          "Exchange Act"), including any amendments or reports filed for the
          purpose of updating such description.

     All documents subsequently filed by the Registrant pursuant to Sections
13(a), 13(c), 14, and 15(d) of the Exchange Act, prior to the filing of a post-
effective amendment to this Registration Statement which indicates that all of
the shares of Common Stock offered have been sold or which deregisters all of
such shares then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be a part hereof from the date
of filing of such documents.  Any statement contained in a document incorporated
or deemed to be incorporated by reference herein shall be deemed to be modified
or superseded for purposes of this Registration Statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such statement.  Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
Registration Statement.

ITEM 4.      DESCRIPTION OF SECURITIES.

     Not applicable.

                                       1
<PAGE>
 
ITEM 5.      INTERESTS OF NAMED EXPERTS AND COUNSEL.

     The validity of the shares of Common Stock offered hereby will be passed
upon for the Registrant by Baker & Hostetler LLP, Columbus, Ohio.  Gary A.
Wadman, a partner of Baker & Hostetler LLP, is the secretary of the Registrant.

ITEM 6.      INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Section 145 of the Delaware General Corporation Law, as amended (the
"DGCL"), provides that a corporation may indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal or investigative
(other than an action by or in the right of the corporation) by reason of the
fact that he is or was a director officer, employee or agent of the corporation,
or is or was serving at the request of the corporation as a director, officer,
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise, against expenses (including attorneys' fees), judgments, fines
and amount paid in settlement actually and reasonably incurred by him in
connection with such action, suit or proceeding if he acted in good faith and in
a manner he reasonably believed to be in or not opposed to the best interests of
the corporation, and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful.  Section 145 further
provides that a corporation similarly may indemnify any such person serving in
any such capacity who was or is a party or is threatened to be made a party to
any threatened, pending or completed action or suit by or in the right of the
corporation to procure a judgment in its favor, against expenses actually and
reasonably incurred in connection with the defense or settlement of such action
or suit if he acted in good faith and in a manner he reasonably believed to be
in or not opposed to the best interests of the corporation and except that no
indemnification shall be made in respect to any claim, issue or matter as to
which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Delaware Court of Chancery or such other
court in which such action or suit was brought shall determine upon application
that, despite the adjudication of liability but in view of all the circumstances
of the case, such person is fairly and reasonably entitled to indemnity for such
expenses which the Court of Chancery or such other court shall deem proper.

     Article 6 of the Amended and Restated By-Laws of the Company, a copy of
which is filed as Exhibit 4(b), contains certain indemnification provisions
adopted pursuant to authority contained in Section 145 of the DGCL.  The By-Laws
provide for the indemnification of the Company's officers, directors, employees,
and agents against all expenses with respect to any judgments, fines, and
amounts paid in settlement, or with respect to any threatened, pending, or
completed action, suit, or proceeding to which they were or are parties or are
threatened to be made parties by reason of acting in such capacities, provided
that it is determined, either by a majority vote of a quorum of disinterested
directors of the Company or by the stockholders of the Company or otherwise as
provided in Section 6.4 of Article 6 of the By-laws, that:  (i) they acted in
good faith and in a manner they reasonably believed to be in or not opposed to
the best interests of the Company; (ii) in any action, suit, or proceeding by or
in the right of the Company, they were not, and have not been adjudicated to
have been, liable to the Company; 

                                       2
<PAGE>
 
and (iii) with respect to any criminal action or proceeding, they had no
reasonable cause to believe that their conduct was unlawful. Section 6.3 of
Article 6 of the By-Laws provides that to the extent a director, officer,
employee, or agent has been successful on the merits or otherwise in defense of
any such action, suit, or proceeding, he shall be indemnified against expenses
actually and reasonably incurred in connection therewith. At present, there are
no claims, actions, suits, or proceedings pending where indemnification would be
required under these provisions, and the Company does not know of any threatened
claims, actions, suits, or proceedings which may result in a request for such
indemnification.

     Under Section 145 of the Delaware Law and Section 6.7 of the By-Laws, the
Company may purchase and maintain insurance on behalf of any person who is or
was a director, officer, employee, or agent of the Company, or who, while
serving in such capacity, is or was, at the request of the Company, a director,
officer, employee or agent of another corporation or legal entity or of an
employee benefit plan, against liability asserted against or incurred by such
person in any such capacity whether or not the corporation would have the power
to provide indemnity under Section 145 or the By-Laws.  The Company has
purchased a liability policy to indemnify its officers and directors against
loss arising from claims by reason of their legal liability for acts as officers
and directors, subject to limitations and conditions set forth in the policy.

     Section 102(b)(7) of the DGCL permits a corporation to include in its
certificate of incorporation a provision eliminating or limiting the personal
liability of a director to the corporation or its stockholders for monetary
damages for breach of fiduciary duty as a director, provided that such provision
shall not eliminate or limit the liability of a director (i) for any breach of
the director's duty of loyalty to the corporation or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL (relating to
unlawful payment of dividends and unlawful stock purchase and redemption) or
(iv) for any transaction from which the director derived an improper personal
benefit.

     Article Ninth of the Second Amended and Restated Certificate of
Incorporation of the Company, a copy of which is filed as Exhibit 4(a),
eliminates personal liability of a director to the Company and its stockholders
for monetary damages for breach of fiduciary as a director to the maximum extent
permitted by Section 102(b)(7) of the DGCL.

     The Underwriting Agreement entered into by the Registrant in connection
with its public offering of Common Stock pursuant to the S-1 (a form of which
appears as Exhibit 1 to the S-1) provides for indemnification of the
Registrant's directors and officers in certain circumstances.  The
indemnification provided for by the Underwriters is limited to matters arising
in connection with the S-1.  Reference is made to paragraph eight of the
Underwriting Agreement for information concerning indemnification undertaken
among the Company and the Underwriters.

     The above discussion of the Company's Certificate of Incorporation and By-
Laws and of Section 145 of the DGCL is not intended to be exhaustive and is
respectively qualified in its entirety by such Certificate of Incorporation, By-
Laws and statutes.

                                       3
<PAGE>
 
ITEM 7.      EXEMPTION FROM REGISTRATION CLAIMED.

     Not applicable.

                                       4
<PAGE>
 
ITEM 8.      EXHIBITS.
<TABLE>
<CAPTION>
                                                              If Incorporated by Reference,
Exhibit                                                      Document with which Exhibit was
 No.                   Description of Exhibit                   Previously Filed with SEC
-------      ------------------------------------------      -------------------------------
<S>          <C>                                            <C>
 4(a)         Second Amended and Restated Certificate       Amendment No. 1 to Registration
              of Incorporation of                           Statement on Form S-1, File No.
              American Dental Partners, Inc.                333-39981 (see Exhibit 3(a) therein).
 
 4(b)         Amended and Restated By-Laws of American      Registration Statement on Form S-1,
              Dental Partners, Inc.                         File No. 333-39981 (see Exhibit 3(b)
                                                            therein).

 4(c)         Form of stock certificate.                    Amendment No. 1 to Registration
                                                            Statement on Form S-1, File No.
                                                            333-39981 (see Exhibit 4 therein).

 4(d)         American Dental Partners, Inc.                Registration Statement on Form S-1,
              Amended and Restated 1996 Stock Option        File No. 333-39981 (see Exhibit 10(e)
              Plan.                                         therein).
 
 4(e)         Amendment No. 1 to American Dental            Amendment No. 4 to Registration
              Partners, Inc. Amended and Restated 1996      Statement on Form S-1, File No.
              Stock Option Plan.                            333-39981 (see Exhibit 10(dd) therein).

 5            Opinion of Baker & Hostetler LLP.             Contained herein.

23(a)         Consent of Baker & Hostetler LLP.             Contained in Exhibit 5.

23(b)         Consent of KPMG Peat Marwick LLP.             Contained herein.

24            Powers of Attorney.                           Registration Statement on Form S-8,
                                                            File No. 333-50605 (see Exhibit 24
                                                            therein).
</TABLE>

ITEM 9.            UNDERTAKINGS.

The Registrant hereby undertakes:

(a)       To file, during any period in which offers or sales are being made, a
          post-effective amendment to this Registration Statement: (i) to
          include any Prospectus required by Section 10(a)(3) of the Securities
          Act; (ii) to reflect in the Prospectus any facts or events arising
          after the effective date of the Registration Statement (or the most
          recent post-effective amendment thereof) which, individually or in the
          aggregate, represent a fundamental change in the information set forth
          in the Registration Statement; and (iii) to include any material
          information with respect to the plan of distribution not previously
          disclosed in the Registration Statement or any material change to such
          information in the Registration Statement.  Provided, however, that
          paragraphs (a)(i) and (a)(ii) shall not apply if the information
          required to be included in a 

                                       5
<PAGE>
 
          post-effective amendment by those paragraphs is contained in periodic
          reports filed by the Registrant pursuant to Section 13 or Section
          15(d) of the Exchange Act that are incorporated by reference in the
          Registration Statement.

(b)       That, for the purpose of determining any liability under the
          Securities Act, each such post-effective amendment shall be deemed to
          be a new Registration Statement relating to the securities offered
          therein, and the offering of such securities at that time shall be
          deemed to be the initial bona fide offering thereof.

(c)       To remove from registration by means of a post-effective amendment any
          of the securities being registered which remain unsold at the
          termination of the offering.

     The Registrant hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of the Registrant's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the Registration Statement shall be deemed to be a
new Registration Statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers, and controlling persons of the
Registrant pursuant to the provisions described in Item 6, above, or otherwise,
the Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Securities Act and is, therefore, unenforceable.  In the event that a
claim for indemnification against such liabilities (other than the payment by
the Registrant of expenses incurred or paid by a director, officer, or
controlling person of the Registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer, or controlling person
in connection with the securities being registered, the Registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act and will be governed by the final adjudication of such issue.

                                       6
<PAGE>
 
                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Wakefield, State of Massachusetts, on July 14, 1998.

                                           AMERICAN DENTAL PARTNERS, INC.


Date:  July 14, 1998                       By  /s/ Gregory A. Serrao
                                           --------------------------
                                           Gregory A. Serrao, Chairman,
                                           President and Chief Executive Officer

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
      Signature                    Title                             Date
      ---------                    -----                             ----
<S>                        <C>                                  <C>
/s/ Gregory A. Serrao       Chairman, President, Chief           July 14, 1998
-------------------------     Executive Officer and 
Gregory A. Serrao             Director (principal   
                              executive officer)     
                             
 
/s/ Ronald M. Levenson      Senior Vice President, Chief         July 14, 1998
-------------------------   Financial Officer and Treasurer                                    
Ronald M. Levenson            (principal financial and      
                              principal accounting officer)  
                            
 
Dr. Gregory T. Swenson*     Director                             July 14, 1998
-------------------------
Dr. Gregory T. Swenson
 
Martin J. Mannion*          Director                             July 14, 1998
-------------------------
Martin J. Mannion
 
James T. Kelly*             Director                             July 14, 1998
-------------------------
James T. Kelly
 
Derril W. Reeves*           Director                             July 14, 1998
-------------------------
Derril W. Reeves
</TABLE>

     *The undersigned, Gregory A. Serrao, by signing his name hereto, does
hereby execute this Registration Statement on behalf of each of the above-named
directors of the Registrant pursuant to powers of attorney duly executed by such
directors and filed with the Securities and Exchange Commission as exhibits to
this Registration Statement.


By /s/ Gregory A. Serrao                                         July 14, 1998
   -------------------------------------------               
   Gregory A. Serrao, Attorney in Fact

                                       7
<PAGE>
 
                                 EXHIBIT INDEX

<TABLE>
<CAPTION>
                                                              If Incorporated by Reference,
Exhibit                                                      Document with which Exhibit was
  No.                   Description of Exhibit                   Previously Filed with SEC
-------      ------------------------------------------      -------------------------------
<S>          <C>                                          <C>
 4(a)         Second Amended and Restated Certificate      Amendment No. 1 to Registration
              of Incorporation of                          Statement on Form S-1, File No.
              American Dental Partners, Inc.               333-39981 (see Exhibit 3(a) therein).
 
 4(b)         Amended and Restated By-Laws of American     Registration Statement on Form S-1,
              Dental Partners, Inc.                        File No. 333-39981 (see Exhibit 3(b)
                                                           therein).

 4(c)         Form of stock certificate.                   Amendment No. 1 to Registration
                                                           Statement on Form S-1, File No.
                                                           333-39981 (see Exhibit 4 therein).

 4(d)         American Dental Partners, Inc. Amended       Registration Statement on Form S-1,
              and Restated 1996 Stock Option Plan.         File No. 333-39981 (see Exhibit 10(e)
                                                           therein).

 4(e)         Amendment No. 1 to American Dental           Amendment No. 4 to Registration
              Partners, Inc. Amended and Restated 1996     Statement on Form S-1, File No.
              Stock Option Plan.                           333-39981 (see Exhibit 10(dd) therein).

 5            Opinion of Baker & Hostetler LLP.            Contained herein.

23(a)         Consent of Baker & Hostetler LLP.            Contained in Exhibit 5.

23(b)         Consent of KPMG Peat Marwick LLP.            Contained herein.

24            Powers of Attorney.                          Registration Statement on Form S-8,
                                                           File No. 333-50605 (see Exhibit 24
                                                           therein).
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 24561}]
{"company-data": {"conformed-name": "AMERICAN DENTAL PARTNERS INC", "cik": "0001028087", "assigned-sic": "8090", "irs-number": "043297858", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-59077", "film-number": "98666066"}, "business-address": {"street1": "301 EDGEWATER PLACE", "street2": "SUITE 320", "city": "WAKEFIELD", "state": "MA", "zip": "01880-1249", "phone": "6172240880"}, "mail-address": {"street1": "301 EDGEWATER PLACE", "street2": "SUITE 320", "city": "WAKEFIELD", "state": "MA", "zip": "01880"}}
As filed with the Securities and Exchange Commission on July 14, 1998
                                                Registration No.333-__________

================================================================================

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549
                           ------------------------
                                        
                                   FORM S-8
                            REGISTRATION STATEMENT
                                   UNDER THE
                            SECURITIES ACT OF 1933

                        AMERICAN DENTAL PARTNERS, INC.
            (Exact name of registrant as specified in its charter)

           Delaware                                       04-3297858
(State or other jurisdiction of                          (IRS Employer 
 Incorporation or organization)                     Identification Number)

                        301 Edgewater Place, Suite 320
                        Wakefield, Massachusetts 01880
              (Address of principal executive offices) (Zip code)

                        American Dental Partners, Inc.
                  Amended and Restated 1996 Stock Option Plan
                           (Full title of the plan)

                  Gregory A. Serrao, Chairman, President and
                            Chief Executive Officer
                        American Dental Partners, Inc.
                        301 Edgewater Place, Suite 320
                        Wakefield, Massachusetts 01880
                                (781) 224-0880
                             (781) 224-4216 (fax)
                (Name, address and telephone number, including
                       area code, of agent for service)

                        CALCULATION OF REGISTRATION FEE
========================================================================================================
                                                           Proposed        Proposed
                                                            maximum        maximum
                                           Amount          offering       aggregate       Amount of
Title of securities                        to be           price per       offering      registration
to be registered                       registered(1)       share(2)        price(2)          fee
--------------------------------------------------------------------------------------------------------
Common Stock, $0.01 par value                973,246            $14.06     $13,683,839          $4,037
========================================================================================================
(1)  Pursuant to Rule 416(a) under the Securities Act of 1933, as amended, this
     Registration Statement also includes an indeterminable number of additional
     shares of Common Stock that may become issuable pursuant to antidilution
     adjustment provisions of the Plan.

(2)  Estimated solely for the purpose of calculating the registration fee in
     accordance with Rules 457(h)(1) and 457(c) under the Securities Act of
     1933, as amended, on the basis of the average of the high and low sale
     prices of the Registrant's Common Stock on the Nasdaq National Market
     System on July 7, 1998.
PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.      INCORPORATION OF DOCUMENTS BY REFERENCE.

     The following documents are incorporated by reference in this Registration
Statement:

(a)       The prospectus filed with the Securities and Exchange Commission on
          April 16, 1998, pursuant to Rule 424(b)(4) under the Securities Act of
          1933, as amended (the "Securities Act"), with respect to the
          Registrant's Registration Statement on Form S-1, File No. 333-39981
          (the "S-1");

(b)       The Registrant's Quarterly Report on Form 10-Q filed with the
          Securities and Exchange Commission on May 11, 1998, and the
          Registrant's Current Report on Form 8-K filed with  the Securities and
          Exchange Commission on June 11, 1998; and

(c)       The description of the Registrant's shares of Common Stock which is
          contained in the Registrant's Registration Statement filed under
          Section 12 of the Securities Exchange Act of 1934, as amended (the
          "Exchange Act"), including any amendments or reports filed for the
          purpose of updating such description.

     All documents subsequently filed by the Registrant pursuant to Sections
13(a), 13(c), 14, and 15(d) of the Exchange Act, prior to the filing of a post-
effective amendment to this Registration Statement which indicates that all of
the shares of Common Stock offered have been sold or which deregisters all of
such shares then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be a part hereof from the date
of filing of such documents.  Any statement contained in a document incorporated
or deemed to be incorporated by reference herein shall be deemed to be modified
or superseded for purposes of this Registration Statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is or is deemed to be incorporated by reference herein modifies or
supersedes such statement.  Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
Registration Statement.

ITEM 4.      DESCRIPTION OF SECURITIES.

     Not applicable.

                                       1
ITEM 5.      INTERESTS OF NAMED EXPERTS AND COUNSEL.

     The validity of the shares of Common Stock offered hereby will be passed
upon for the Registrant by Baker & Hostetler LLP, Columbus, Ohio.  Gary A.
Wadman, a partner of Baker & Hostetler LLP, is the secretary of the Registrant.

ITEM 6.      INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Section 145 of the Delaware General Corporation Law, as amended (the
"DGCL"), provides that a corporation may indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal or investigative
(other than an action by or in the right of the corporation) by reason of the
fact that he is or was a director officer, employee or agent of the corporation,
or is or was serving at the request of the corporation as a director, officer,
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise, against expenses (including attorneys' fees), judgments, fines
and amount paid in settlement actually and reasonably incurred by him in
connection with such action, suit or proceeding if he acted in good faith and in
a manner he reasonably believed to be in or not opposed to the best interests of
the corporation, and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful.  Section 145 further
provides that a corporation similarly may indemnify any such person serving in
any such capacity who was or is a party or is threatened to be made a party to
any threatened, pending or completed action or suit by or in the right of the
corporation to procure a judgment in its favor, against expenses actually and
reasonably incurred in connection with the defense or settlement of such action
or suit if he acted in good faith and in a manner he reasonably believed to be
in or not opposed to the best interests of the corporation and except that no
indemnification shall be made in respect to any claim, issue or matter as to
which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Delaware Court of Chancery or such other
court in which such action or suit was brought shall determine upon application
that, despite the adjudication of liability but in view of all the circumstances
of the case, such person is fairly and reasonably entitled to indemnity for such
expenses which the Court of Chancery or such other court shall deem proper.

     Article 6 of the Amended and Restated By-Laws of the Company, a copy of
which is filed as Exhibit 4(b), contains certain indemnification provisions
adopted pursuant to authority contained in Section 145 of the DGCL.  The By-Laws
provide for the indemnification of the Company's officers, directors, employees,
and agents against all expenses with respect to any judgments, fines, and
amounts paid in settlement, or with respect to any threatened, pending, or
completed action, suit, or proceeding to which they were or are parties or are
threatened to be made parties by reason of acting in such capacities, provided
that it is determined, either by a majority vote of a quorum of disinterested
directors of the Company or by the stockholders of the Company or otherwise as
provided in Section 6.4 of Article 6 of the By-laws, that:  (i) they acted in
good faith and in a manner they reasonably believed to be in or not opposed to
the best interests of the Company; (ii) in any action, suit, or proceeding by or
in the right of the Company, they were not, and have not been adjudicated to
have been, liable to the Company; 

                                       2
and (iii) with respect to any criminal action or proceeding, they had no
reasonable cause to believe that their conduct was unlawful. Section 6.3 of
Article 6 of the By-Laws provides that to the extent a director, officer,
employee, or agent has been successful on the merits or otherwise in defense of
any such action, suit, or proceeding, he shall be indemnified against expenses
actually and reasonably incurred in connection therewith. At present, there are
no claims, actions, suits, or proceedings pending where indemnification would be
required under these provisions, and the Company does not know of any threatened
claims, actions, suits, or proceedings which may result in a request for such
indemnification.

     Under Section 145 of the Delaware Law and Section 6.7 of the By-Laws, the
Company may purchase and maintain insurance on behalf of any person who is or
was a director, officer, employee, or agent of the Company, or who, while
serving in such capacity, is or was, at the request of the Company, a director,
officer, employee or agent of another corporation or legal entity or of an
employee benefit plan, against liability asserted against or incurred by such
person in any such capacity whether or not the corporation would have the power
to provide indemnity under Section 145 or the By-Laws.  The Company has
purchased a liability policy to indemnify its officers and directors against
loss arising from claims by reason of their legal liability for acts as officers
and directors, subject to limitations and conditions set forth in the policy.

     Section 102(b)(7) of the DGCL permits a corporation to include in its
certificate of incorporation a provision eliminating or limiting the personal
liability of a director to the corporation or its stockholders for monetary
damages for breach of fiduciary duty as a director, provided that such provision
shall not eliminate or limit the liability of a director (i) for any breach of
the director's duty of loyalty to the corporation or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL (relating to
unlawful payment of dividends and unlawful stock purchase and redemption) or
(iv) for any transaction from which the director derived an improper personal
benefit.

     Article Ninth of the Second Amended and Restated Certificate of
Incorporation of the Company, a copy of which is filed as Exhibit 4(a),
eliminates personal liability of a director to the Company and its stockholders
for monetary damages for breach of fiduciary as a director to the maximum extent
permitted by Section 102(b)(7) of the DGCL.

     The Underwriting Agreement entered into by the Registrant in connection
with its public offering of Common Stock pursuant to the S-1 (a form of which
appears as Exhibit 1 to the S-1) provides for indemnification of the
Registrant's directors and officers in certain circumstances.  The
indemnification provided for by the Underwriters is limited to matters arising
in connection with the S-1.  Reference is made to paragraph eight of the
Underwriting Agreement for information concerning indemnification undertaken
among the Company and the Underwriters.

     The above discussion of the Company's Certificate of Incorporation and By-
Laws and of Section 145 of the DGCL is not intended to be exhaustive and is
respectively qualified in its entirety by such Certificate of Incorporation, By-
Laws and statutes.

                                       3
ITEM 7.      EXEMPTION FROM REGISTRATION CLAIMED.

     Not applicable.

                                       4
ITEM 8.      EXHIBITS.
If Incorporated by Reference,
Exhibit                                                      Document with which Exhibit was
 No.                   Description of Exhibit                   Previously Filed with SEC
-------      ------------------------------------------      -------------------------------
4(a)         Second Amended and Restated Certificate       Amendment No. 1 to Registration
              of Incorporation of                           Statement on Form S-1, File No.
              American Dental Partners, Inc.                333-39981 (see Exhibit 3(a) therein).
 
 4(b)         Amended and Restated By-Laws of American      Registration Statement on Form S-1,
              Dental Partners, Inc.                         File No. 333-39981 (see Exhibit 3(b)
                                                            therein).

 4(c)         Form of stock certificate.                    Amendment No. 1 to Registration
                                                            Statement on Form S-1, File No.
                                                            333-39981 (see Exhibit 4 therein).

 4(d)         American Dental Partners, Inc.                Registration Statement on Form S-1,
              Amended and Restated 1996 Stock Option        File No. 333-39981 (see Exhibit 10(e)
              Plan.                                         therein).
 
 4(e)         Amendment No. 1 to American Dental            Amendment No. 4 to Registration
              Partners, Inc. Amended and Restated 1996      Statement on Form S-1, File No.
              Stock Option Plan.                            333-39981 (see Exhibit 10(dd) therein).

 5            Opinion of Baker & Hostetler LLP.             Contained herein.

23(a)         Consent of Baker & Hostetler LLP.             Contained in Exhibit 5.

23(b)         Consent of KPMG Peat Marwick LLP.             Contained herein.

24            Powers of Attorney.                           Registration Statement on Form S-8,
                                                            File No. 333-50605 (see Exhibit 24
                                                            therein).
ITEM 9.            UNDERTAKINGS.

The Registrant hereby undertakes:

(a)       To file, during any period in which offers or sales are being made, a
          post-effective amendment to this Registration Statement: (i) to
          include any Prospectus required by Section 10(a)(3) of the Securities
          Act; (ii) to reflect in the Prospectus any facts or events arising
          after the effective date of the Registration Statement (or the most
          recent post-effective amendment thereof) which, individually or in the
          aggregate, represent a fundamental change in the information set forth
          in the Registration Statement; and (iii) to include any material
          information with respect to the plan of distribution not previously
          disclosed in the Registration Statement or any material change to such
          information in the Registration Statement.  Provided, however, that
          paragraphs (a)(i) and (a)(ii) shall not apply if the information
          required to be included in a 

                                       5
post-effective amendment by those paragraphs is contained in periodic
          reports filed by the Registrant pursuant to Section 13 or Section
          15(d) of the Exchange Act that are incorporated by reference in the
          Registration Statement.

(b)       That, for the purpose of determining any liability under the
          Securities Act, each such post-effective amendment shall be deemed to
          be a new Registration Statement relating to the securities offered
          therein, and the offering of such securities at that time shall be
          deemed to be the initial bona fide offering thereof.

(c)       To remove from registration by means of a post-effective amendment any
          of the securities being registered which remain unsold at the
          termination of the offering.

     The Registrant hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of the Registrant's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the Registration Statement shall be deemed to be a
new Registration Statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers, and controlling persons of the
Registrant pursuant to the provisions described in Item 6, above, or otherwise,
the Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Securities Act and is, therefore, unenforceable.  In the event that a
claim for indemnification against such liabilities (other than the payment by
the Registrant of expenses incurred or paid by a director, officer, or
controlling person of the Registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer, or controlling person
in connection with the securities being registered, the Registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act and will be governed by the final adjudication of such issue.

                                       6
SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Wakefield, State of Massachusetts, on July 14, 1998.

                                           AMERICAN DENTAL PARTNERS, INC.

Date:  July 14, 1998                       By  /s/ Gregory A. Serrao
                                           --------------------------
                                           Gregory A. Serrao, Chairman,
                                           President and Chief Executive Officer

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.
Signature                    Title                             Date
      ---------                    -----                             ----
/s/ Gregory A. Serrao       Chairman, President, Chief           July 14, 1998
-------------------------     Executive Officer and 
Gregory A. Serrao             Director (principal   
                              executive officer)     
                             
 
/s/ Ronald M. Levenson      Senior Vice President, Chief         July 14, 1998
-------------------------   Financial Officer and Treasurer                                    
Ronald M. Levenson            (principal financial and      
                              principal accounting officer)  
                            
 
Dr. Gregory T. Swenson*     Director                             July 14, 1998
-------------------------
Dr. Gregory T. Swenson
 
Martin J. Mannion*          Director                             July 14, 1998
-------------------------
Martin J. Mannion
 
James T. Kelly*             Director                             July 14, 1998
-------------------------
James T. Kelly
 
Derril W. Reeves*           Director                             July 14, 1998
-------------------------
Derril W. Reeves
*The undersigned, Gregory A. Serrao, by signing his name hereto, does
hereby execute this Registration Statement on behalf of each of the above-named
directors of the Registrant pursuant to powers of attorney duly executed by such
directors and filed with the Securities and Exchange Commission as exhibits to
this Registration Statement.

By /s/ Gregory A. Serrao                                         July 14, 1998
   -------------------------------------------               
   Gregory A. Serrao, Attorney in Fact

                                       7
EXHIBIT INDEX
If Incorporated by Reference,
Exhibit                                                      Document with which Exhibit was
  No.                   Description of Exhibit                   Previously Filed with SEC
-------      ------------------------------------------      -------------------------------
4(a)         Second Amended and Restated Certificate      Amendment No. 1 to Registration
              of Incorporation of                          Statement on Form S-1, File No.
              American Dental Partners, Inc.               333-39981 (see Exhibit 3(a) therein).
 
 4(b)         Amended and Restated By-Laws of American     Registration Statement on Form S-1,
              Dental Partners, Inc.                        File No. 333-39981 (see Exhibit 3(b)
                                                           therein).

 4(c)         Form of stock certificate.                   Amendment No. 1 to Registration
                                                           Statement on Form S-1, File No.
                                                           333-39981 (see Exhibit 4 therein).

 4(d)         American Dental Partners, Inc. Amended       Registration Statement on Form S-1,
              and Restated 1996 Stock Option Plan.         File No. 333-39981 (see Exhibit 10(e)
                                                           therein).

 4(e)         Amendment No. 1 to American Dental           Amendment No. 4 to Registration
              Partners, Inc. Amended and Restated 1996     Statement on Form S-1, File No.
              Stock Option Plan.                           333-39981 (see Exhibit 10(dd) therein).

 5            Opinion of Baker & Hostetler LLP.            Contained herein.

23(a)         Consent of Baker & Hostetler LLP.            Contained in Exhibit 5.

23(b)         Consent of KPMG Peat Marwick LLP.            Contained herein.

24            Powers of Attorney.                          Registration Statement on Form S-8,
                                                           File No. 333-50605 (see Exhibit 24
                                                           therein).