<PAGE>   1
                                                                   EXHIBIT 10.14

                            STOCK PURCHASE AGREEMENT


     THIS AGREEMENT, dated August 5, 1998 (the "Signing Date"), is between
American Dental Technologies, Inc., a Delaware corporation ("ADT"), and Ultrak,
Inc., a Delaware corporation ("Ultrak").

     Recitals. Ultrak owns all of the issued and outstanding Common Stock,
$0.01 par value per share (the "DVD Stock"), of Dental Vision Direct, Inc., a
Texas corporation ("DVD"). DVD owns all of the issued and outstanding Common
Stock, $0.01 par value per share (the "VVI Stock"), of Veravision, Inc., a Texas
corporation ("VVI"). ADT desires to acquire the issued and outstanding DVD Stock
from Ultrak in accordance with the terms of this Agreement.

     NOW, THEREFORE, in consideration of the foregoing and the terms of this
Agreement, the receipt and adequacy of which are hereby acknowledged, the
parties hereto, intending to be legally bound, hereby covenant and agree as
follows:


                            ARTICLE I: THE PURCHASE

     1.01. The Purchase. On the terms and subject to the conditions set forth
herein, at the Closing (as hereinafter defined) ADT agrees to purchase from
Ultrak, and Ultrak agrees to sell to ADT, on the Closing Date (as hereinafter
defined) 11,111 shares of the DVD Stock (the "Shares").

     1.02. Purchase Price.

          (a) The purchase price to be paid to Ultrak by ADT for the Shares
     shall be an amount equal to the aggregate of Sections 1.02(a)(i), 
     1.02(a)(ii), 1.02(a)(iii), and 1.02(a)(iv) below (collectively, the 
     "Purchase Price"):

               (i)    Three Million Dollars ($3,000,000); plus

               (ii)   DVD's inventory as reflected on DVD's books at actual
                      cost; provided, however, Ultra Cam II inventory shall be
                      valued at one-half of actual cost; provided further,
                      however, the term "actual cost" for this Section
                      1.02(a)(iii) shall mean historical transfer price without
                      inter-company profit for inventory manufactured and sold
                      to DVD by Ultrak; plus

               (iii)  DVD's current assets (excluding DVD's cash and cash
                      equivalents) as reflected on DVD's books as of the date
                      hereof; plus

               (iv)   DVD's furniture and equipment at their cost less
                      accumulated depreciation as reflected on DVD's books as of
                      the date hereof.

     At the Closing, the parties shall complete and execute Schedule A showing
     the calculation of the Purchase Price.

          (b) The Purchase Price shall be paid by ADT paying Ultrak Three
     Million Dollars ($3,000,000) in cash (the "Cash Purchase Price") at the
     Closing by wire transfer and delivering to


<PAGE>   2
     Ultrak at the Closing a Promissory Note in the form of Exhibit A attached
     hereto (the "Note") and a Stock Pledge Agreement, with original stock
     certificates representing the Shares issued in ADT's name and a duly
     executed blank stock power for each stock certificate, in the form of
     Exhibit B attached hereto (the "Pledge Agreement").

     1.03. Other Matters.

          (a) At the Closing, each of ADT and Ultrak shall execute and deliver
     to the other a Consulting and Non-Competition Agreement in the form of
     Exhibit C attached hereto (the "Consulting Agreement").

          (b) At the Closing, ADT shall execute and deliver to (i) Ultrak a
     Common Stock Purchase Warrant in the form of Exhibit D attached hereto (the
     "Warrant") and (ii) Ronald Williams ("Williams") a Common Stock Purchase
     Warrant in the form of Exhibit E attached hereto (the "Williams Warrant").

          (c) Ultrak agrees to continue to allow DVD to use the office space at
     Ultrak's Lewisville, Texas facility currently occupied by DVD's employees
     through December 31, 1998 without charge. Neither DVD nor ADT shall be
     entitled to utilize any of Ultrak's warehouse space except for the ninety
     (90) days pursuant to Section 1.05.

          (d) Ultrak agrees to continue to provide to DVD the current level of
     engineering support or such lesser amount of engineering support as may be
     necessary to complete the PAL version of Ultra Cam III (the "First
     Project") and the image capture CD Product (the "Second Project"). ADT or
     DVD will be fully and solely responsible (and Ultrak shall not be
     responsible) for payment of any third party charges and costs associated
     with the First Project and the Second Project and for obtaining any
     consents or approvals of third parties required in connection with the
     First Project or the Second Project and Ultrak makes no representation or
     warranty to ADT that any consent or approval will be granted or obtained.
     Ultrak's responsibilities for the First Project shall cease upon Ultrak
     delivering to ADT the deliverables set forth on Schedule B attached hereto.
     Ultrak's responsibility for the Second Project shall cease upon Ultrak
     delivering to ADT the deliverables set forth on Schedule C attached hereto.

          (e) ADT acknowledges and agrees that all cash, cash equivalents, and
     receivables (the "DVD Receivables") of DVD as of the Closing are hereby
     transferred by DVD to Ultrak as of the Closing.

     1.04. Collection of Accounts Receivable. ADT agrees to collect, and cause
DVD to collect, the DVD Receivables for and on behalf of Ultrak. ADT shall use
all reasonable best efforts to promptly collect the DVD Receivables. ADT shall
create and maintain detailed records on the collection of the DVD Receivables.
Each Friday by 2:00 p.m., Dallas, Texas time, ADT shall cause an amount equal to
the DVD Receivables collected and not previously sent to Ultrak to be wire
transferred to Ultrak to such bank account(s) as Ultrak shall identify in
writing. In addition, upon originating the wire transfer each Friday, ADT shall
telecopy to Ultrak a detailed listing of the DVD Receivables collected and
included in the wire transfer. On the first business day that is at least ninety
(90) days after the Closing Date, ADT will wire transfer to Ultrak an amount
equal to the total face amount of the DVD Receivables not yet collected by ADT
and Ultrak shall 


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<PAGE>   3
assign such uncollected DVD Receivables to ADT, without recourse. Ultrak shall
have the full right to review and audit ADT's books and records in connection
with the DVD Receivables.

     1.05.   Inventory. ADT shall cause DVD's inventory to be removed from
Ultrak's Lewisville, Texas facility within ninety (90) days from the Closing
Date. ADT will not be charged by Ultrak for using Ultrak's facility during such
ninety (90) days. During such period that DVD's inventory is at Ultrak's
facility after the Closing, (a) Ultrak shall have no duties or responsibilities
with respect to such inventory (other than as set forth in (c) of this Section
1.05), (b) DVD and/or ADT shall be responsible for insuring, maintaining, and
protecting such inventory, and (c) Ultrak shall fill orders from such inventory
on behalf of DVD or ADT. In consideration for Ultrak filling orders, ADT shall
pay Ultrak $3,000 per month for each of the first two months and $5,000 per
month for the third month. Payments to Ultrak shall be due on the fifteenth of
each month, with the first payment due on August 15, 1998. Time is of the
essence with respect to such payments. ADT shall be solely responsible and
liable for loading and shipping to ADT or DVD the DVD inventory from Ultrak's
facility at the end of the ninety (90) day period and for any other inventory
that ADT earlier ships, or causes to be shipped, from Ultrak's facilities to ADT
or DVD and shall be liable for any loss or damage during loading or shipment.

     1.06.   Closing. The closing of the transactions contemplated by this
Agreement (the "Closing") shall take place at Ultrak's offices in Lewisville,
Texas on the Signing Date, at 10:00 o'clock a.m. The day on which the Closing
occurs is herein referred to as the "Closing Date."

     1.07.   Further Assurances. After the Closing, each party shall execute and
deliver such additional documents and take such additional actions as the other
party may reasonably deem to be practical and necessary or advisable in order
to consummate the transactions contemplated by this Agreement.

     1.08.   Effective Date. Notwithstanding anything to the contrary in this
Agreement, the transactions contemplated hereby shall, for all purposes
(including but not limited to accounting purposes), be effective as of 12:01
a.m. on August 1, 1998.

              ARTICLE II: REPRESENTATIONS AND WARRANTIES OF ULTRAK

     Ultrak represents and warrants to ADT that the following are true and
correct:

     2.01.   Organization, Qualification, and Good Standing. Ultrak is a
corporation duly organized and validly existing under Delaware law and has the
corporate power and authority to own or hold under lease its properties and
assets and to carry on its business as it is now being conducted. Each of DVD
and VVI is a corporation duly organized and validly existing under Texas law and
has the corporate power and authority to own or hold under lease its properties
and assets and to carry on its business as it is now being conducted.

     2.02.  Corporate Records. Each of the minute books of DVD and VVI contains
accurate and complete minutes of all meetings of and accurate and complete
consents to all actions taken without meetings by the board of directors (and
any committee thereof) and the shareholders of such corporation.

     2.03.  Corporate Authority Relative to This Agreement; No Violation. Ultrak
has the corporate power to enter into this Agreement and to carry out its
obligations hereunder. The execution and delivery of this Agreement and the
Consulting Agreement and the consummation of the transactions contemplated
hereby and thereby have been duly and validly authorized by Ultrak's board of
directors and no other corporate


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proceedings on the part of Ultrak are necessary to authorize this Agreement, the
Consulting Agreement, or the transactions contemplated hereby. Each of this
Agreement and the Consulting Agreement has been duly and validly executed and
delivered by Ultrak and, assuming each such document constitutes a valid and
binding agreement of each other party thereto, each such document constitutes a
valid and binding agreement of Ultrak, enforceable against Ultrak in accordance
with its terms. Neither the execution and delivery of this Agreement and the
Consulting Agreement by Ultrak nor the consummation of the transactions
contemplated hereby and thereby by Ultrak will: (a) violate or conflict with
any provision of the Charter or Bylaws of Ultrak, (b) violate or conflict with,
or result in the breach or termination of, or otherwise give any other
contracting party the right to terminate, or constitute a default (or an event
which, with the lapse of time, or the giving of notice, or both, will constitute
a default) under, any contract, license, other instrument or commitment to which
Ultrak is a party or by which Ultrak is bound (assuming the consent of
NationsBank of Texas, N.A. is obtained), or (c) violate or conflict with any
applicable law, regulation, permit, authorization, franchise, license, judgment,
order, writ, injunction or decree of any court or governmental body of any
jurisdiction. Other than the consent of NationsBank of Texas, N.A., no
authorization, consent, or approval of, or filing with, any governmental body or
authority, any lender or lessor, or any other person or entity is required to
authorize, or is required in connection with, the execution, delivery, and
performance of this Agreement or the agreements contemplated hereby on the part
of Ultrak.

     2.04. Capitalization. The authorized capital stock of DVD consists solely
of 1,000,000 shares of DVD Stock, and only the Shares are issued and outstanding
as of the date hereof. The authorized capital stock of VVI consists solely of
1,000,000 shares of VVI Stock, 1,000 shares of which are issued and outstanding
on the date hereof. Ultrak owns the Shares. DVD owns all of the issued and
outstanding VVI Stock. All outstanding shares of DVD Stock and VVI Stock are
duly authorized, validly issued, fully paid, and nonassessable. There are no
preemptive rights with respect to the DVD Stock or the VVI Stock. There are no
outstanding subscriptions, options, warrants, rights, or other arrangements or
commitments, whether express or implied, granted or issued by Ultrak or DVD
obligating DVD to issue any shares of DVD Stock or securities exchangeable for
or convertible into DVD Stock.

     2.05. The Shares. The Shares are free and clear of all liens, liabilities, 
claims and encumbrances, except for general securities laws restrictions.

     2.06. DVD Financials. The unaudited monthly financial statements of DVD as
of the end of February 1998, March 1998, April 1998, May 1998 and June 1998 (a)
were compiled from the books and records of DVD, which books and records are, to
the best knowledge of Ultrak, complete, maintained on a consistent basis, and
correctly reflect DVD's income, expenses, assets and liabilities, and (b) are
true, complete and accurate and present fairly the financial position of DVD as
of the dates thereof and for the periods covered thereby. The inventory value
reports for Lewisville and California, the Customer Aging Summary as of July 28,
1998, and the Fixed Assets Detail as of June 30, 1998 for DVD that were
previously delivered to Ultrak were true, complete, and accurate as of their
respective dates.

     2.07. Compliance with Laws. DVD has complied with all laws, rules, and/or
regulations applicable to it or its business, other than individual items of
non-compliance that would not have a material adverse effect on DVD.

     2.08. Taxes. DVD has duly filed when due all income, excise, corporate,
franchise, property, sales, payroll, withholding, and other tax returns and
reports required to be filed by it by the U.S. government or any state or any
political subdivision thereof and has paid or established adequate reserves for
all taxes which have


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or may become due for the periods covered by such returns. All such tax returns
or reports which are income tax returns or reports fairly reflect the taxable
income generated by DVD and the taxes of DVD for the periods covered thereby.
DVD is not delinquent in the payment of any tax and there is no tax deficiency
or delinquency being asserted against DVD.

     2.09.     Litigation and Claims. Ultrak has not received notice that DVD 
is a party to, or that the business and assets of DVD are the subject of or 
affected by, any pending or threatened suit, claim, action, or litigation by or 
with any party or any administrative, arbitration, or other governmental 
proceeding, investigation, or inquiry. DVD is not (a) subject to any continuing
court or administrative order, writ, injunction, or decree applicable 
specifically to DVD or to its business, assets, operations, or employees, or 
(b) in default with respect to any such order, writ, injunction, or decree.

     2.10.     Brokers and Finders. Neither Ultrak nor DVD has employed any 
broker, finder, or investment bank or incurred any liability for any investment 
banking fees, financial advisory fees, brokerage fees, or finders' fees in 
connection with the transactions contemplated hereby.


               ARTICLE III: REPRESENTATIONS AND WARRANTIES OF ADT

     ADT represents and warrants to Ultrak that the following are true and 
correct:

     3.01.     Organization, Qualification, and Good Standing. ADT is a
corporation duly organized, validly existing, and in good standing under the 
laws of the State of Delaware, and ADT has the corporate power and authority to 
own or hold under lease its properties and assets and to carry on its business 
as it is now being conducted.

     3.02.     Corporate Authority Relative to This Agreement; No Violation. 
ADT has the corporate power to enter into this Agreement and to carry out its
obligations hereunder. The execution and delivery of this Agreement, the Note,
the Pledge Agreement, the Consulting Agreement, the Warrant, and the Williams
Warrant and the consummation of the transactions contemplated hereby and thereby
have been duly and validly authorized by ADT's board of directors and no other
corporate proceedings on the part of ADT are necessary to authorize this
Agreement, the Note, the Pledge Agreement, the Consulting Agreement, the
Warrant, the Williams Warrant, or the transactions contemplated hereby. Each of
this Agreement, the Note, the Pledge Agreement, the Consulting Agreement, the
Warrant, and the Williams Warrant has been duly and validly executed and
delivered by ADT and, assuming each such document constitutes a valid and
binding agreement of each other party thereto, each such document constitutes a
valid and binding agreement of ADT, enforceable against ADT in accordance with
its terms. Neither the execution and delivery of this Agreement, the Note, the
Pledge Agreement, the Consulting Agreement, the Warrant, and the Williams
Warrant by ADT nor the consummation of the transactions contemplated hereby and
thereby by ADT will: (a) violate or conflict with any provision of the
Certificate of Incorporation or Bylaws of ADT, (b) violate or conflict with, or
result in the breach or termination of, or otherwise give any other contracting
party the right to terminate, or constitute a default (or an event which, with
the lapse of time, or the giving of notice, or both, will constitute a default)
under, any contract, license, other instrument or commitment to which ADT is a
party or by which ADT is bound, or (c) violate or conflict with any law,
regulation, permit, authorization, franchise, license, judgment, order, writ,
injunction or decree of any court or governmental body of any jurisdiction, in
each case as such is related to ADT or its assets.


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     3.03. Consents. No authorization, consent, or approval of, or filing with, 
any governmental body or authority, any lender or lessor, or any other person 
or entity is required to authorize, or is required in connection with, the 
execution, delivery, and performance of this Agreement or the agreements 
contemplated hereby on the part of ADT.

     3.04. Brokers and Finders. ADT has not employed any broker, finder, or 
investment bank or incurred any liability for any investment banking fees, 
financial advisory fees, brokerage fees, or finders' fees in connection with 
the transactions contemplated hereby.

                          ARTICLE IV: COVENANTS OF ADT

     4.01. Employee Severance. ADT agrees that if any employee of DVD or VVI is 
terminated by ADT, DVD, or VVI on or after the Closing, then ADT shall, upon 
termination, pay each such terminated employee an amount equal to one week of 
such employee's then base salary for each year of service with DVD, VVI, or 
VVI's predecessor-in-interest with a minimum payment to each such terminated 
employee of two weeks of base salary.

     4.02. Product Warranty Work and Claims. DVD shall be fully and solely 
responsible for all warranty repairs, warranty replacements, and warranty 
returns for credit with respect to the products previously or hereafter sold by 
or for the account of DVD.

                          ARTICLE V: CLOSING DELIVERIES

     5.01. Deliveries by ADT. At the Closing, ADT shall deliver to Ultrak each 
of the following (with each document duly executed by ADT):

          (a) The Cash Purchase Price.

          (b) The Note.

          (c) The Pledge Agreement.
       
          (d) The Warrant.

          (e) The Consulting Agreement.

          (f) Certified Resolutions of ADT's Board of Directors approving the
execution, delivery, and performance of this Agreement, the Note, the Pledge
Agreement, the Warrant, the Williams Warrant, and the Consulting Agreement by
ADT and the consummation by ADT of the transactions contemplated hereby and
thereby.

          (g) such other documents as Ultrak shall reasonably request.

     5.02. Deliveries by Ultrak. At the Closing, Ultrak shall deliver to ADT 
each of the following (with each document duly executed by Ultrak):

          (a) Stock Certificate(s) representing the Shares.


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           (b)  Stock Power(s) transferring the Shares to ADT.

           (c)  The Consulting Agreement.

           (d)  Certified Resolutions of Ultrak's Board of Directors approving 
     the execution, delivery, and performance of this Agreement, the Stock 
     Power(s), and the Consulting Agreement by Ultrak and the consummation by 
     Ultrak of the transactions contemplated hereby and thereby.

           (e)  Such other documents as ADT shall reasonably request.


                          ARTICLE VI: INDEMNIFICATION

     6.01. Mutual Indemnity. Subject to the terms and conditions of this 
Article VI, (a) ADT hereby agrees to indemnify, defend and hold Ultrak and 
Ultrak's officers, directors, and affiliates harmless from and against all 
losses, claims, obligations, demands, assessments, penalties, liabilities, 
costs, damages, attorneys' fees and expenses (collectively, "Damages"), 
asserted against or incurred by them by reason of or resulting from (i) any 
breach by ADT of any representation, warranty, or covenant contained herein or 
in any agreement executed pursuant hereto (including but not limited to the 
obligations under Section 4.01 hereof) or (ii) the failure of DVD to pay or 
perform any of its liabilities or obligations under Section 4.02 hereof or 
arising on or after the Effective Date and (b) Ultrak hereby agrees to 
indemnify, defend and hold ADT and ADT's officers, directors, and affiliates 
harmless from and against all Damages asserted against or incurred by them by 
reason of or resulting from (i) any breach by Ultrak of any representation, 
warranty, or covenant contained herein or in any agreement executed pursuant 
hereto or (ii) any liability or obligation of DVD or VVI for any act or 
activity of DVD or VVI that occurred prior to the Effective Date to the end 
that ADT shall be in the same position vis a vis DVD and VVI as if it had 
purchased the assets of DVD and VVI; provided, however, that, notwithstanding 
anything to the contrary in this Agreement, Ultrak shall have no liability or 
responsibility under this Section 6.01 or under any other provision of this 
Agreement for any matter covered by Sections 4.01 or 4.02 hereof.

     6.02. Conditions of Indemnification. The indemnity obligations under 
Section 6.01 hereof shall be subject to the following terms and conditions:

           (a) Within 20 days (or such earlier time as might be required to
avoid prejudicing the indemnifying party's position) after receipt of notice of
commencement of any action evidenced by service of process, or other legal
pleading, or with reasonable promptness after the assertion in writing of any
claim by a third party of a matter for which a party (the"indemnified party") is
entitled to indemnification under Section 6.01, the indemnified party shall give
the other party (the "indemnifying party") written notice thereof together with
a copy of such claim, process, or other legal pleading, and the indemnifying
party shall have the right to undertake the defense thereof by representatives
of its own choosing and at its own expense; provided, however, that the
indemnified party may participate in the defense with counsel of its own choice
and at its own expense. Notwithstanding the foregoing, if, in the reasonable
opinion of counsel to the indemnified party (which opinion must be furnished in
writing to the indemnified party), a potential conflict of interest shall exist
as between the indemnifying party and the indemnified party such that it would
not be in the best interest of the indemnified party to be represented by the
same counsel as the indemnifying party, the indemnified party shall be entitled
to retain separate counsel, all at the expense of the indemnified party;
provided, however, that in no


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<PAGE>   8
        event shall the indemnifying party be required to pay for more than one
        counsel for the indemnified party in any lawsuit, action, proceeding, or
        claim (including any related lawsuits, actions, proceedings, or claims).

            (b)   If the indemnifying party, by the 20th day after receipt of
        notice of any such claim (or, if earlier, by the 10th day preceding the
        day on which an answer or other pleading must be served in order to
        prevent judgment by default in favor of the person asserting such
        claim), does not notify in writing the indemnified party that the
        indemnifying party shall defend against such claim, then the
        indemnified party may (upon further notice to the indemnifying party)
        undertake the defense, compromise, or settlement of such claim on
        behalf of and for the account and risk of the indemnifying party and at
        the indemnifying party's expense, subject to the right of the
        indemnifying party to assume the defense of such claim at any time
        prior to settlement, compromise, or final determination thereof.

            (c)   Anything in this Section 6.02 to the contrary notwithstanding,
        the indemnifying party shall not settle any claim without the consent of
        the indemnified party unless such settlement involves only the payment
        of money and the claimant provides to the indemnified party a full and
        complete release from all liability in respect of such claim. If the
        settlement of the claim involves more than the payment of money, then
        the indemnifying party shall not settle the claim without the prior
        written consent of the indemnified party, which consent shall not be
        unreasonably withheld.

            (d)   Each of Ultrak and ADT will cooperate with all reasonable
        requests of the other pursuant to Section 6.01 and this Section 6.02.

        6.03.     Remedies Not Exclusive. The remedies provided in this 
Article VI shall not be exclusive of any other rights or remedies available by 
one party against the other, either at law or in equity; provided, however, 
that the parties agree to arbitrate disputes pursuant to Section 7.09.

                           ARTICLE VII: MISCELLANEOUS

        7.01.     Modification, Amendment and Waiver. This Agreement may not be 
modified unless such modification is in writing and signed by all parties 
hereto. No waiver of any term of this Agreement shall be enforceable unless in 
writing and signed by the party against which it is sought to be enforced. The 
waiver by any party of a breach of any provision of this Agreement shall not 
operate or be construed as a waiver of any subsequent breach by such party.

        7.02.     Expenses. Each party shall bear its own expenses incurred in 
connection with the preparation of this Agreement and the consummation of the 
transactions contemplated hereby; provided, however, in connection with the 
fees and expenses of Grant Thornton to audit the financial statements of DVD as 
of December 31, 1997, each of ADT and Ultrak shall pay one-half of such fees 
and expenses.

        7.03.     Counterparts. This Agreement may be executed in two or more 
counterparts, all of which will be considered the same agreement and faxed 
copies of manually executed signature pages to this Agreement will be fully 
binding and enforceable without the need for delivery of the manually executed 
signature page.

        7.04.     GOVERNING LAW. THE INTERNAL LAWS (AND NOT THE CONFLICTS OF 
LAWS RULES) OF TEXAS GOVERN THIS AGREEMENT.



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<PAGE>   9
        7.05.     Notices. All notices hereunder will be in writing and will be 
deemed given if delivered personally (or by recognized with postage prepaid 
courier or delivery service) or mailed by registered or certified air mail 
(return receipt requested with postage prepaid) to the parties at the following 
addresses (or at such other addresses for a party as will be specified by like 
notice) and will be deemed given on the date on which personally delivered or
delivered by courier or delivery service or on the third business day following
the date on which so mailed to the address set forth opposite the name and
signature block for each party to this Agreement.

        7.06.     Survival. All representations, warranties and covenants made 
by ADT and Ultrak herein or in any agreement, certificate or other instrument 
delivered by it hereunder shall be considered to have been relied upon by Ultrak
or ADT and shall survive the Closing, regardless of any investigation made by 
or on behalf of Ultrak or ADT.

        7.07.     Severability. If any provision of this Agreement is held to 
be illegal, invalid, or unenforceable, such provision shall be fully severable, 
and this Agreement shall be construed and enforced as if such illegal, invalid, 
or unenforceable provision were never a part hereof; the remaining provisions 
hereof shall remain in full force and effect and shall not be affected by the 
illegal, invalid, or unenforceable provision or by its severance; and in lieu 
of such illegal, invalid, or unenforceable provision, there shall be added 
automatically as part of this Agreement, a provision as similar in its terms to 
such illegal, invalid, or unenforceable provision as may be possible and be 
legal, valid, and enforceable.

        7.08.     Assignments; Entire Agreement; Headings. This Agreement shall 
not be assignable by operation of law or otherwise. Any attempted assignment of 
this Agreement shall be void. This Agreement, the Schedules attached hereto, and
the Exhibits attached hereto constitute the entire agreement, and supersede all 
other prior agreements and understandings, both written and oral, between the 
parties, or any of them, with respect to the subject matter hereof. All 
Schedules, Exhibits, and documents and agreements referred to herein or 
attached hereto are fully and completely incorporated herein effective as of 
the first reference herein. The headings contained in this Agreement are for
reference purposes and will not affect in any way the meaning or interpretation
of this Agreement. Use of "herein," "hereof" or similar terms refer to this
Agreement as a whole. The use of any term denoting a masculine, feminine, or
neuter gender shall include all such genders.

        7.09.     Arbitration. ANY DISPUTE OR CLAIM RELATING TO THIS AGREEMENT 
SHALL BE FINALLY SETTLED BY BINDING ARBITRATION IN ACCORDANCE WITH THE RULES OF 
THE AMERICAN ARBITRATION ASSOCIATION (THE "ABA") WHICH RULES ARE DEEMED TO BE 
INCORPORATED HEREIN BY REFERENCE. THE ABA SHALL APPOINT THE ARBITRATOR. ANY 
SUCH ARBITRATION SHALL BE HELD IN SAN ANTONIO, TEXAS. JUDGMENT UPON THE AWARD 
RENDERED BY THE ARBITRATOR MAY BE ENTERED IN ANY COURT HAVING JURISDICTION 
THEREOF. THE ARBITRATOR SHALL BE AUTHORIZED AND ENTITLED TO AWARD THE COSTS AND 
EXPENSES OF ANY ARBITRATION.


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     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed and delivered as of the date first above written.

Address for Ultrak:                    ULTRAK, INC.

1301 Waters Ridge Drive
Lewisville, Texas 75057                By:  /s/ GEORGE K. BROADY
Fax # 972-353-6513                          -------------------------------
Attn: George K. Broady                      George K. Broady, CEO



Address for ADT:

5555 Bear Lane                         AMERICAN DENTAL TECHNOLOGIES, INC.
Corpus Christi, Texas 78405
Fax # 512-289-5554
Attn: Ben J. Gallant
                                       By:  /s/ BEN J. GALLANT
                                            -------------------------------
                                            Ben J. Gallant, President & CEO



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<PAGE>   11
                                                                      SCHEDULE A

                           PURCHASE PRICE CALCULATION



        1.       Three Million Dollars                          $ 3,000,000.00

        2.       DVD's Inventory at actual cost                   3,582,236.67
                                                                --------------
                 Rule:  Ultra Cam II inventory at 50% of
                        actual cost
                 Rule:  Intercompany inventory manufactured 
                        by Ultrak at transfer price

        3.       DVD's Current Assets                                51,481.00
                                                                --------------

                 Rule: Exclude Cash and Cash Equivalents

        4.       DVD's net Furniture and Equipment                  266,613.50
                                                                --------------

                                                                       (331.17)
                                                                --------------

                       TOTAL PURCHASE PRICE:                    $ 6,900,000.00
                                                                --------------



        APPROVED:


        AMERICAN DENTAL                     ULTRAK, INC.
        TECHNOLOGIES, INC.

        By: /s/ BEN J. GALLANT              By: /s/ GEORGE K. BROADY
            -------------------------------     --------------------------------
            Ben J. Gallant, President &         George K. Broady, CEO
            CEO