EXHIBIT 10.1

AMENDMENT TO SERVICE AGREEMENT

This amendment is entered into with an effective date of January 1, 2007,
between Wisconsin Dental Group, S.C., a Wisconsin service corporation
(“Provider”), and American Dental Partners of Wisconsin, LLC, a Delaware limited
liability company (“Service Company”), who hereby agree as follows:

1. Definitions. All capitalized terms used in this amendment which are not
otherwise defined herein shall have the respective meanings given to those terms
in the Amended and Restated Service Agreement dated January 1, 1999 (the
“Service Agreement”).

2. Service Fee. The percentage set forth in the last sentence of Section 7.3 of
the Service Agreement is hereby set at 90%.

3. Provider Retained Earnings. The percentage set forth in Section 7.8 of the
Service Agreement is hereby set at 10%.

4. Effective Date. This amendment shall be effective as of the date first set
forth above.

5. Construction. This is an amendment to and a part of the Service Agreement. In
the event of any inconsistency between the provisions of the Service Agreement
and the provisions of this amendment, the provisions of this amendment shall
control prospectively from the effective date of this amendment. Except as
modified by this amendment, the Service Agreement shall continue in full force
and effect without change.

 

WISCONSIN DENTAL GROUP, S.C.

   

AMERICAN DENTAL PARTNERS OF WISCONSIN, LLC

By:

 

/s/ Robert Trettin

   

By:

 

/s/ Ian H. Brock

 

Robert Trettin, D.D.S., President

     

Ian H. Brock, Vice President

Date of Execution: 2/15/2007

   

Date of Execution: 2/15/2007