Exhibit 4.7

                             SECURED PROMISSORY NOTE

$2,000,000.00                                                  December 28, 2007

      FOR VALUE RECEIVED, VISION OPPORTUNITY MASTER FUND, LTD, a corporation
organized under the laws of the Cayman Islands ("Borrower"), hereby covenants
and promises to pay to the order of DENTALSERV.COM, a corporation organized
under the laws of the state of Nevada ("Lender") in lawful money of the United
States of America and in immediately available funds, the principal sum of Two
Million Dollars ($2,000,000.00) (the "Loan") together with accrued and unpaid
interest thereon, each due and payable on the dates and in the manner set forth
below. Such Loan constitutes deferred payment for approximately 1,025,881 shares
of Lender's Series A Convertible Preferred Stock issued by Lender to Borrower
(the "Stock" and, together with the Class A, B, J, and C Warrants issued or
issuable to Borrower under that certain Series A Convertible Preferred Stock
Purchase Agreement among Borrower, Lender and the other parties thereto and
dated September 5, 2007 (the "SPA") the "Pledged Stock") pursuant to the SPA.

      1.    Principal Repayment. The outstanding principal amount of the Loan
            shall be due and payable on March 31, 2008 (the "Principal Repayment
            Date").

      2.    Interest Rate. The Loan shall not bear interest.

      3.    Place of Payment. All amounts payable hereunder shall be payable to
            Lender at 817 Winchester Road, Suite 200, Lexington, Kentucky 40505
            unless another place of payment shall be specified in writing by
            Lender.

      4.    Application of Payments. Except as otherwise provided herein,
            payment on this Note shall be applied first to accrued interest, and
            thereafter to the outstanding principal balance hereof.

      5.    Terms of Repayment. Up until the Principal Repayment Date, Vision
            shall have the sole and exclusive option of (i) repaying the Loan
            and receiving the certificates for Stock issued in its name, or (ii)
            facilitating the purchase of the stock by a third party purchaser (a
            "Third Party Purchaser"). For avoidance of doubt, in the event the
            Stock is purchased by a Third Party Purchaser, such Third Party
            Purchaser shall remit payment of $2,000,000 to Lender, in accordance
            with the terms of an escrow agreement dated as of the date hereof
            related thereto (the "Escrow Agreement") and, accordingly, this Loan
            shall thereby be cancelled.

      6.    Prepayment. Borrower may pay the entire outstanding balance of
            principal and all accrued and unpaid interest thereon at any time
            before the Principal Payment Date (a "Prepayment") without penalty.

      7.    Waiver by Borrower. Borrower waives presentment and demand for
            payment, notice of dishonor, protest and notice of protest of this
            Note. The right to plead any and all statutes of limitations as a
            defense to any demands hereunder is hereby waived to the full extent
            permitted by law.

      8.    Collections. Should the indebtedness represented by this Note or any
            part thereof be collected at law or in equity, or in bankruptcy,
            receivership or any other court proceedings (whether at the trial or
            appellate level), or should this Note be placed in the hands of
            attorneys for collection upon default, Borrower agrees to pay, in
            addition to the principal, premium and interest due and payable
            hereon, all costs of collection or attempting to collect this Note,
            including reasonable attorneys fees and expenses.

<PAGE>

      9.    Amendment. This Note may not be amended orally, but only by an
            agreement in writing, signed by the party against whom enforcement
            of any waiver, change, modification or discharge is sought.

      10.   Late Charge. Borrower recognizes and agrees that any default of any
            the payment due hereunder will result in loss and additional
            expenses to Lender in servicing the indebtedness evidenced hereby,
            handling such delinquent payments and meeting Lender's other
            financial obligations, the extent of which loss and additional
            expenses is extremely difficult and impractical to ascertain.
            Borrower therefore agrees that in the event that any payment
            hereunder is not paid on the date it becomes due, for any reason
            other than an error for which an independent banking institution or
            wire service is determined to be wholly responsible, then in
            addition to all other rights set forth herein, or in the Pledge
            Agreement, dated as of the date hereof, between Borrower and Lender
            (the "Pledge Agreement"), Lender shall have the right to collect a
            late charge equal to four percent (4%) of the delinquent payment.
            The right to collect such late charge shall be in addition to all
            other rights granted to Lender hereunder.

      11.   Default. At the option of Lender, without prior notice, and
            regardless of any prior forbearance, all sums remaining unpaid under
            this Note shall become immediately due and payable upon the
            occurrence of a default by Borrower under this Note, or the Pledge
            Agreement. The failure of Borrower to pay any amount due under the
            terms of this Note when the same becomes due and payable, if such
            failure remains unremedied for a period of five (5) calendar days
            following receipt by Borrower of written notice from Lender of such
            failure to pay, shall constitute a default by Borrower under this
            Note. Furthermore, any default under the Pledge Agreement, which
            remains uncured within the timelines specified therein shall also be
            considered a default by Borrower under this Note.

      12.   Time. Time is strictly of the essence in this Note.

      13.   No Waiver by Lender. No delay or omission on the part of Lender in
            exercising any right under this Note, or under any other agreement
            or instrument securing this Note shall operate as a waiver of such
            right on any future occasion, or of any other rights under this Note
            or any agreement or instrument securing this Note.

      14.   Cumulative Rights. All rights and remedies of Lender provided for in
            this Note are cumulative and shall be in addition to all other
            rights and remedies provided in the Security Agreement or by law or
            in equity.

      15.   Notices. Except as otherwise provided herein, any notice or other
            communication herein required or permitted to be given shall be in
            writing and may be delivered in person, with receipt acknowledged,
            or sent by facsimile or by United States mail, registered or
            certified, return receipt requested, postage prepaid and addressed
            as follows:

               i.   If to Lender:   Dentalserv.com/Medpro Safety Products, Inc.
                                      817 Winchester Road
                                      Lexington, KY 40505
                                      Facsimile: (859) 225-5347
                                      Attention: Walter Weller, President

               ii.  With a copy to: Frost Brown Todd LLC
                                      250 West Main, Suite 2700
                                      Lexington, Kentucky 40505
                                      Facsimile: (859) 231-0011
                                      Attention: Paul E. Sullivan, Esq.

               iii. If to Borrower: Vision Opportunity Master Fund, Ltd.

<PAGE>

                                      20 W. 55th Street
                                      New York, NY 10019
                                      Attn: Adam Benowitz, Portfolio Manager

               iv.  With a copy to: Lord Locke Bissell & Liddell LLP
                                      885 Third Avenue
                                      New York, NY 10022
                                      Facsimile: (212) 947-1202
                                      Attention: Corey N. Martin, Esq.

Any party may change its address or facsimile number by giving the other party
prior notice of the change in accordance with the provisions of this Section 15.

      16.   Governing Law; Venue. This Note shall be governed by, and construed
            and enforced in accordance with, the laws of the State of Delaware,
            excluding conflict of laws principles that would cause the
            application of laws of any other jurisdiction. The parties agree
            that any suit, action or proceeding arising out of or relating to
            this Note, or the interpretation, performance, or breach of this
            Note, may, but do not have to be, instituted in the Supreme Court
            for the County of Manhattan, State of New York, and each party
            irrevocably submits to the jurisdiction of said court, and waives
            all objections to jurisdiction or venue that it may have under the
            laws of the State of New York or otherwise in any suit, action or
            proceeding, except that Lender reserves the right to institute such
            supplemental local actions in other venues as may be necessary to
            preserve or collect the collateral identified in the Pledge
            Agreement, or to enforce Lender's rights therein.

      17.   Successors and Assigns. The provisions of this Note shall inure to
            the benefit of and be binding on any successor to Borrower and shall
            extend to any holder hereof.

      18.   Security Agreement/Subordination. This Note is secured by the Pledge
            Agreement executed by Borrower and Lender creating a security
            interest in the Pledged Stock, which Pledge Agreement specifies
            various defaults upon the happening of which all sums on this Note
            may, at Lender's option, be declared immediately due and payable.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK.]

<PAGE>

      IN WITNESS WHEREOF, Borrower has executed and delivered this Note on the
day and year first above written.

                              VISION OPPORTUNITY MASTER FUND, LTD, a corporation
                              organized under the laws of the Cayman Islands

                              By: ______________________________________________

                              Name: ____________________________________________

                              Its: _____________________________________________