<PAGE>   1
                                                                     EXHIBIT 4.4


                                                                     EXHIBIT B-2
                                                             TO CREDIT AGREEMENT



                     FORM OF ADDITIONAL TRANCHE A TERM NOTE

THIS NOTE MAY NOT BE TRANSFERRED EXCEPT IN COMPLIANCE WITH THE TERMS AND
PROVISIONS OF THE THIRD AMENDED AND RESTATED CREDIT AGREEMENT REFERRED TO BELOW.
TRANSFERS OF THIS NOTE MUST BE RECORDED IN THE REGISTER MAINTAINED BY THE
ADMINISTRATIVE AGENT PURSUANT TO THE TERMS OF SUCH THIRD AMENDED AND RESTATED
CREDIT AGREEMENT.


$                                                             New York, New York
 -----
                                                                   -------------


         FOR VALUE RECEIVED, Nalge Nunc International Corporation ("NNI"), a
Delaware corporation (the "Borrower"), hereby unconditionally promises to pay to
the order of               (the "Lender") at the office of The Chase Manhattan
Bank, located at 270 Park Avenue, New York, New York 10017, in lawful money of
the United States of America and in immediately available funds, in accordance
with subsection 2.29 of the Credit Agreement, the lesser of (a) the principal
amount of          DOLLARS ($ ), and (b) the aggregate unpaid principal amount
of the Additional Tranche A Term Loan (or portion thereof) made by the Lender to
the Borrower pursuant to subsection 2.28 of the Credit Agreement, as hereinafter
defined. The principal amount of such Additional Tranche A Term Loan shall be
paid in accordance with subsection 2.29 of the Credit Agreement. The Borrower
further agrees to pay interest in like money at such office on the unpaid
principal amount of Additional Tranche A Term Loans of the Borrower from time to
time outstanding at the rates and on the dates specified in subsection 2.19 of
such Credit Agreement.

         The holder of this Note is authorized to endorse on the appropriate
schedules annexed hereto and made a part hereof or on a continuation thereof
which shall be attached hereto and made a part hereof the date, Type and amount
of the Additional Tranche A Term Loan made by the holder to the Borrower and the
date and amount of each payment or prepayment of principal with respect thereto,
each conversion of all or a portion thereof to another Type, each continuation
of all or a portion thereof as the same Type and, in the case of Eurodollar
Loans, the length of each Interest Period and the Eurodollar Rate with respect
thereto. Each such endorsement shall constitute prima facie evidence of the
accuracy of the information endorsed. The failure to make any such endorsement
shall not affect the obligations of the Borrower in respect of such Additional
Tranche A Term Loan.

         This Note (a) is one of the Additional Tranche A Term Notes referred to
in the Third Amended and Restated Credit Agreement dated as of July __, 1999 (as
amended, supplemented or otherwise modified from time to time, the "Credit
Agreement"), among Sybron International Corporation, a Wisconsin corporation,
Ormco Corporation, a Delaware corporation, Kerr Corporation, a Delaware
corporation, NNI, Erie Scientific Company, a Delaware corporation, Barnstead
Thermolyne

<PAGE>   2

                                                                               2



Corporation, a Delaware corporation, Remel Inc., a Wisconsin corporation, the
Lender, the other banks and financial institutions from time to time parties
thereto, Chase Securities Inc., as arranger, and The Chase Manhattan Bank, as
administrative agent, (b) is subject to the provisions of the Credit Agreement
and (c) is subject to optional and mandatory prepayment in whole or in part as
provided in the Credit Agreement. This Note is secured and guaranteed as
provided in the Loan Documents. Reference is hereby made to the Loan Documents
for a description of the assets in which a security interest has been granted,
the nature and extent of the security and the guarantees, the terms and
conditions upon which the security interests and each guarantee were granted and
the rights of the holder of this Note in respect thereof.

         Upon the occurrence of any one or more of the Events of Default, all
amounts then remaining unpaid on this Note shall become, or may be declared to
be, immediately due and payable, all as provided in the Credit Agreement.

         All parties now and hereafter liable with respect to this Note, whether
maker, principal, surety, guarantor, endorser or otherwise, hereby waive
presentment, demand, protest and all other notices of any kind, except as
otherwise provided in any of the Loan Documents.

         Unless otherwise defined herein, terms defined in the Credit Agreement
and used herein shall have the meanings given to them in the Credit Agreement.

         THIS NOTE SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.


                                      NALGE NUNC INTERNATIONAL CORPORATION


                                      By:
                                         ---------------------------------------
                                         Name:
                                         Title:


<PAGE>   3



                                                                      Schedule A
                                               to Additional Tranche A Term Note

                                       NNI
                 LOANS, CONVERSIONS AND REPAYMENTS OF ABR LOANS

<TABLE>
<CAPTION>

------------------------------------------------------------------------------------------------------------------------------------

                                Amount                               Amount of ABR Loans
                             Converted to   Amount of Principal of      Converted to          Unpaid Principal
 Date  Amount of ABR Loans    ABR Loans        ABR Loans Repaid       Eurodollar Loans      Balance of ABR Loans  Notation Made By
------------------------------------------------------------------------------------------------------------------------------------
<S>   <C>                   <C>            <C>                      <C>                    <C>                   <C>

------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


====================================================================================================================================

</TABLE>


<PAGE>   4



                                                                      Schedule B
                                               to Additional Tranche A Term Note

                                       NNI
      LOANS, CONTINUATIONS, CONVERSIONS AND REPAYMENTS OF EURODOLLAR LOANS


<TABLE>
<CAPTION>

------------------------------------------------------------------------------------------------------------------------------------

                                                                          Amount of        Amount of       Unpaid Principal
                                               Interest Period and      Principal of       Eurodollar         Balance of
          Amount of        Amount Converted    Eurodollar Rate with   Eurodollar Loans  Loans Converted to    Eurodollar    Notation
 Date  Eurodollar Loans   to Eurodollar Loans     Respect Thereto          Repaid           ABR Loans           Loans       Made By
------------------------------------------------------------------------------------------------------------------------------------
<S>   <C>                <C>                  <C>                    <C>               <C>                <C>              <C>

------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


------------------------------------------------------------------------------------------------------------------------------------


====================================================================================================================================

</TABLE>