<PAGE>   1
                                                                     EXHIBIT 4.3


                                                                     EXHIBIT B-1
                                                             TO CREDIT AGREEMENT



                           FORM OF 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, each of the undersigned, Ormco Corporation
("Ormco"), a Delaware corporation, Kerr Corporation ("Kerr"), a Delaware
corporation, Nalge Nunc International Corporation ("NNI"), a Delaware
corporation, Erie Scientific Company ("Erie"), a Delaware corporation and
Barnstead Thermolyne Corporation ("Barnstead"), a Delaware corporation (each, a
"Borrower"), severally, 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 2.12 of the Credit Agreement, the lesser of (a) the principal amount
of (i) in the case of each of Ormco, Erie and Barnstead individually,
DOLLARS ($), (ii) in the case of Kerr,                 DOLLARS ("$ ), and (iii)
in the case of NNI,            DOLLARS ($ ), and (b) the aggregate unpaid
principal amount of the Tranche A Term Loan (or portion thereof) made by the
Lender to such Borrower pursuant to subsection 2.11 of the Credit Agreement, as
hereinafter defined. The principal amount of such Tranche A Term Loan shall be
paid in consecutive quarterly installments, payable on the last day of each
October, January, April and July commencing on October 31, 2000 in accordance
with subsection 2.12 of the Credit Agreement. Each Borrower, severally, further
agrees to pay interest in like money at such office on the unpaid principal
amount of Tranche A Term Loans of such 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 Tranche A Term Loan made by the holder to each 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 Tranche A Term Loan.



<PAGE>   2



         This Note (a) is one of the 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, Kerr, NNI, Erie, Barnstead, 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.

                                      ORMCO CORPORATION


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



                                      KERR CORPORATION



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


<PAGE>   3



                                      NALGE NUNC INTERNATIONAL CORPORATION


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



                                      ERIE SCIENTIFIC COMPANY


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



                                      BARNSTEAD THERMOLYNE CORPORATION


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


<PAGE>   4



                                                                    Schedule A-1
                                                          to Tranche A Term Note

                                      ORMCO
                 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>

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


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

</TABLE>


<PAGE>   5



                                                                    Schedule A-2
                                                          to Tranche A Term Note

                                      KERR
                 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>

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


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

</TABLE>


<PAGE>   6



                                                                    Schedule A-3
                                                          to 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>

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


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

</TABLE>


<PAGE>   7



                                                                    Schedule A-4
                                                          to Tranche A Term Note

                                      ERIE
                 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>

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


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


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

</TABLE>


<PAGE>   8



                                                                    Schedule A-5
                                                          to Tranche A Term Note

                                    BARNSTEAD
                 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>

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


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


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


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

</TABLE>


<PAGE>   9



                                                                    Schedule B-1
                                                          to Tranche A Term Note

                                      ORMCO
      LOANS, CONTINUATIONS, CONVERSIONS AND REPAYMENTS OF EURODOLLAR LOANS



<TABLE>
<CAPTION>

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

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

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


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

</TABLE>


<PAGE>   10



                                                                    Schedule B-2
                                                          to Tranche A Term Note

                                      KERR
      LOANS, CONTINUATIONS, CONVERSIONS AND REPAYMENTS OF EURODOLLAR LOANS



<TABLE>
<CAPTION>

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

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

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


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

</TABLE>


<PAGE>   11



                                                                    Schedule B-3
                                                          to Tranche A Term Note

                                       NNI
      LOANS, CONTINUATIONS, CONVERSIONS AND REPAYMENTS OF EURODOLLAR LOANS



<TABLE>
<CAPTION>

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

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

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


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

</TABLE>


<PAGE>   12



                                                                    Schedule B-4
                                                          to Tranche A Term Note

                                      ERIE
      LOANS, CONTINUATIONS, CONVERSIONS AND REPAYMENTS OF EURODOLLAR LOANS



<TABLE>
<CAPTION>

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

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

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

</TABLE>


<PAGE>   13



                                                                    Schedule B-5
                                                          to Tranche A Term Note

                                    BARNSTEAD
      LOANS, CONTINUATIONS, CONVERSIONS AND REPAYMENTS OF EURODOLLAR LOANS



<TABLE>
<CAPTION>

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

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

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

</TABLE>