<PAGE>   1
                                                                   EXHIBIT 10.54

May 30, 1997

Mr. Lawrence Ceraulo
Certex Dental Studio
2001 N. State Road 7
No. A1
Margate, FL 33063

     Re:  MASON DENTAL SOUTHEAST, INC. ("MASON SOUTHEAST")
            RENAISSANCE DENTAL STUDIO ("RENAISSANCE")

Dear Mr. Ceraulo:

     The following represents the terms and conditions upon which, for good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, (i) Mason Southeast will sell all of the assets of Mason
Southeast to Mr. Lawrence Ceraulo d/b/a Certex Dental Studio (collectively,
"Certex"), and (ii) Certex will assume any and all rights and obligations
regarding Renaissance from Mason Dental Midwest, Inc. ("Mason Midwest").

        1. Mason Southeast Assets. All tangible and intangible assets
of Mason Southeast presently located at the Mason Southeast laboratory facility
including, but not limited to, equipment, supplies, inventory, customer lists,
records, insurance contracts, employment agreements, furniture and fixtures,
all as a going concern ("Mason Southeast Assets"), will be sold to Certex by
Mason Southeast in accordance with the terms and conditions contained in this
agreement. All of the Mason Southeast Assets shall be sold free and clear of
all liens, claims and encumbrances. The parties agree and acknowledge that the
Mason Southeast Assets will not include: (i) cash on hand at closing, (ii)
accounts receivable outstanding as of the date of closing, (iii) M&J deposit in
the amount of $10,000.00, (iii) that certain Ford Escort automobile presently
owned by Mason Southeast, (iv) prepaid insurance in the amount of $2,712.00,
and (v) any and all assets associated with Renaissance, which are being
transferred as specified in Paragraph 3 hereof.

        2. Mason Southeast Liabilities. Mason Southeast is being sold to 
Certex as an ongoing business, and it is anticipated that, except as specified
herein, Certex is assuming any ongoing liabilities of Mason Southeast.
Provided, however, that Certex is specifically not assuming the following
liabilities: (i) outstanding Mason Southeast accounts payable incurred prior to
the closing date, and (ii) that certain FMC Note in the amount of $8,010.00.

        3. Renaissance Assignment and Assumption. Mason Midwest shall assign to
Certex, and Certex would assume, any and all rights and ongoing obligations
relating to Renaissance including, without limitation, those outlined in (i)
Agreement of Purchase and Sale dated as of August 29, 1996 between Gerald
L. Kunze ("Kunze") and Mason Midwest, (ii) Employment Agreement dated as of
September 5, 1996 betweens Kunze and Mason Midwest, (iii) Security Agreement
dated as of September 5, 1996 between Kunze and Mason Midwest, and (iv)



<PAGE>   2
Promissory Note in the initial principal amount of $21,626.76 executed by Mason
Midwest in favor of Kunze and dated September 5, 1996 (collectively, the
"Renaissance Agreements").

        4. Purchase Price. The purchase price for the Mason Southeast Assets 
would be $92,096.00, increased by the agreed value of the supplies being
transferred, payable in readily available bank funds at closing; provided,
however, that at the sole option of Mason Southeast, Mason Southeast may
elect to allow Certex to pay the full amount of the purchase price in the form
of a Forty-Five (45) day secured note in form and substance acceptable to Mason
Southeast. The purchase price with respect to Renaissance would be the
assumption of the Promissory Note included within the Renaissance Agreements.

        5. Accounts Receivable.  Mason Southeast and Renaissance accounts
receivable for work/services rendered in the ordinary course of business prior
to the date of closing would be the property of, and would accrue to the
benefit of, Mason Southeast. Mason Southeast and Renaissance accounts
receivable for work/services rendered in the ordinary course of business after
the date of closing would be the property of, and would accrue to the benefit
of, Certex.

        6. Work in Progress. Mason Southeast and Renaissance work in progress
created in the ordinary course of business prior to the date of closing would
be the property of, and would accrue to the benefit of, Mason Southeast.

        7. Liabilities. Mason Southeast and Renaissance accounts payable 
incurred in the ordinary course of business prior to the date of closing would
be the responsibility of Mason Southeast. Any and all liabilities incurred
post-closing in connection with the ongoing operation of Mason Southeast and
Renaissance including, without limitation, the employment and payment of
benefits (including, without limitation, any accrued vacation time) to the
individuals listed on Exhibit A attached hereto and incorporated herein
(collectively, the "Mason Southeast and Renaissance Employees"), shall be
solely Certex's responsibility.





<PAGE>   3
        8. Ongoing Contractual Relationship. Certex agrees that, for a period of
three (3) years from the closing date, it shall, at the sole option of the
Florida Dental Team, P.A., continue to provide dental laboratory services as
may be required to members of The Florida Dental Team, P.A. at the same price
and on the same terms as are presently provided by Mason Southeast and/or
Renaissance to The Florida Dental Team, P.A. The parties acknowledge that it is
essential that Certex be able to meet all volume and quality requirements of
The Florida Dental Team, P.A., and Certex represents and warrants that Certex
will be able to meet or exceed such requirements. The parties further
acknowledge that this agreement was an essential inducement for Mason Southeast
to enter into this agreement with Certex, and the parties agree that Mason
Southeast, and/or The Florida Dental Team, P.A., shall be entitled to
injunctive relief, in addition to any suit for damages, in the event that
Certex violates this agreement.

        9. Certain Taxes.  Mason Southeast would pay current as of the date of
closing, all state and federal payroll taxes relating to Mason Southeast and
Renaissance, including but not limited to, Medicare, unemployment, and Social
Security on the Mason Southeast and Renaissance Employees.

        In addition, both parties acknowledge that it may be necessary for a
consolidated income tax return to be filed regarding Mason Southeast for the
year in which the closing occurs, and both parties agree to cooperate in this
regard.

        10.  Fringe Benefits; Insurance.  Mason Southeast would pay current
through the date of closing (i) all accrued but unpaid 401(k) deposits for all
the Mason Southeast and Renaissance Employees, (ii) all health insurance
premiums for all of the Mason Southeast and Renaissance Employees, (iii) all
payments due to third party health care providers regarding the Mason Southeast
and Renaissance Employees, and (iv) all insurance premiums for worker's
compensation insurance (if any) relating to the Mason Southeast and Renaissance
Employees.

        11. Building Leases.  All amounts due under the building leases 
currently in existence for Mason Southeast and Renaissance would be paid 
current through the date of closing. The parties acknowledge that, at present,
no amounts are  due from Mason Southeast in this regard other than currently
pending monthly lease payments. Post closing, all responsibilities under such
leases would be the sole responsibility of Certex. The parties agree to use
their very best efforts to obtain the consent of the landlord for the
assignment and assumption of that certain Lease Agreement dated February 26,
1993 regarding the Pompano Square Dental Lab location; provided, however, that,
in the event that such consent is delayed or otherwise not obtained, the
parties shall enter into a pass-through arrangement whereby Certex shall be
solely responsible for any and all obligations pursuant to such Lease
Agreement.

        12. Record Keeping. Certex would agree to maintain in the ordinary 
course of business all prior business records of Mason Southeast and 
Renaissance and to provide reasonable access to such records to Mason Southeast
and Mason Southeast's agents.

        13. Closing Date.  The closing date for the transactions set forth in 
this letter agreement shall be as of June 1, 1997.


<PAGE>   4
        14. Documentation. This Agreement is entirely subject to the approval of
the Board of Directors of Mason Southeast and Mason Midwest, but otherwise
constitutes a legally binding obligation on the parties hereto without the need
for any additional documentation; provided, however, that the parties mutually
agree to enter into any other documentation which may be deemed reasonably
necessary by counsel solely in order to properly effectuate the transactions
contemplated herein.  All parties shall bear their own costs in this regard,
including those of legal counsel.

        If these terms are acceptable to you, please indicate your acceptance by
initialling each page, signing this letter below and returning it to us via
telecopy and overnight mail. This letter agreement may be signed in individual
counterparts, each of which together shall constitute a legal, valid and
binding agreement among the parties.

Sincerely,

MASON DENTAL SOUTHEAST, INC.


___________________________
Gary A. Lockwood, President


MASON DENTAL MIDWEST, INC.


___________________________
Gary A. Lockwood, President



AGREED AND ACCEPTED:



_______________________________
Lawrence Ceraulo, individually
and d/b/a Certex Dental Studio