<PAGE>

                               SIXTH AMENDMENT TO
                         SERVICES AND SUPPORT AGREEMENT

         This Sixth Amendment to Service and Support Agreement (the "SIXTH
AMENDMENT") effective as of October 1, 2002 (the "EFFECTIVE DATE") is by and
between Coast Dental Services, Inc., a Florida corporation ("CDS") and Coast
Florida, P.A., a Florida professional corporation (the "DENTAL PRACTICE ENTITY"
or the "P.A.").

                                 R E C I T A L S

         WHEREAS, CDS and Dental Practice Entity are parties to that certain
Services and Support Agreement dated as of October 1, 1996, amended on June 1,
1997, further amended on October 1, 1998, further amended on February 1, 1999,
further amended on January 1, 2000, and further amended on June 1, 2002 (the
"SERVICES AND SUPPORT AGREEMENT");

         WHEREAS, CDS and Dental Practice Entity desire to amend the Services
and Support Agreement to change the methodology for determining the monthly
services and support fee (the "S&S FEE") earned by CDS for its services and
support to Dental Practice Entity;

         WHEREAS, this change was precipitated by the favorable impact on the
financial performance of Dental Centers converted to the recently implemented
Dental Equity Model, which model provides the equity dentist and the Dental
Practice Entity an incentive for improving financial performance. This amendment
will incorporate the financial performance of each Dental Center in the
determination of the S&S Fee earned by CDS.

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged by the parties, the parties agree
to modify, supplement and amend the Services and Support Agreement as follows:

         1.       Recitals. The statements contained in the Recitals of facts
set forth above are true and correct and are by this reference made a part of
this Sixth Amendment.

         2.       Exhibit A. Exhibit "A" to the Services and Support Agreement
is hereby deleted in its entirety and the Exhibit "A" attached hereto is
substituted therefor.

         3.       Other Provisions. All of the term and provisions contained in
the Services and Support Agreement shall remain in full force and effect unless
specifically modified, supplemented or amended by this Sixth Amendment. Defined
terms used but not otherwise defined herein shall have the meanings given to
them in the Services and Support Agreement.


<PAGE>




         IN WITNESS WHEREOF, the parties have hereunto set their hands and seals
on the day and year first above written.

                                "DENTAL PRACTICE ENTITY"

                                COAST FLORIDA, P.A.


                                By: /s/ ADAM DIASTI
                                    -------------------------------------
                                    Adam Diasti, D.D.S., President

                                "CDS"

                                COAST DENTAL SERVICES, INC.


                                By: /s/ TIMOTHY G. MERRICK
                                    -------------------------------------
                                    Timothy G. Merrick, Vice President


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                               SIXTH AMENDMENT TO
                         SERVICES AND SUPPORT AGREEMENT

                                   EXHIBIT "A"

                            SERVICES AND SUPPORT FEE

1.       CDS will earn an S&S Fee calculated as follows:

         a.       CDS will receive a fee based on the actual Dental Center
                  Expenses; and

         b.       CDS will receive a variable, performance-based, fee set at 90%
                  of the excess of net dental services revenue over Dental
                  Center Expenses calculated at the aggregate level for, and
                  using the aggregate financial performance of, the entire
                  portfolio of all Dental Centers serviced and supported by CDS.

         As used herein, "Dental Center Expenses" shall mean all actual direct
         and indirect operating and non-operating expenses incurred by CDS in
         providing services and support to the Dental Center, including, without
         limitation:

                           (i)      Salaries, benefits, and other direct costs
                  of all employees of CDS at the Dental Center, including dental
                  assistants (but excluding all Dentists and dental hygienists);

                           (ii)     Direct costs of all employees or consultants
                  of CDS who provide services at or in connection with the
                  Dental Center required for improved clinic performance, such
                  as work management, materials management, purchasing, charge
                  and coding analysis, and business office consultation;

                           (iii)    Other direct and indirect expenses incurred
                  by CDS or an affiliate of CDS in providing services and
                  support to the Dental Centers including dental supplies and
                  lab fees, advertising and promotional costs, rent and
                  occupancy costs, depreciation on assets used at the Dental
                  Center, and Dental Center general and administrative expenses;
                  other than the kind of expenses listed in items (i) and (ii)
                  above;

                           (iv)     Personal property and intangible taxes
                  assessed against CDS's assets used in connection with the
                  operation of the Dental Center, commencing on the date of this
                  Agreement;

                           (v)      Interest expense on indebtedness incurred by
                  CDS to finance any of its obligations hereunder or services
                  provided hereunder;

                           (vi)     Malpractice insurance expenses and dentist
                  recruitment expenses; and


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                           (vii)    Other expenses incurred by CDS in carrying
                    out its obligations under this Agreement.


                    "Dental Center Expenses" shall not include:

                           (i)      Any federal or state income taxes;

                           (ii)     Any bad debt and related expense; and

                           (iii)    Any expenses which are expressly designated
                    herein as expenses or responsibilities of the Dental
                    Practice Entity.

2.       The portion of the S&S Fee that is based on the actual Dental Center
         expenses will be calculated on a stand-alone basis for and using the
         stand-alone financial performance of each Dental Center.



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