1 EXHIBIT 4.5 SECOND AMENDMENT, dated as of August 13, 1998 (this "Amendment"), to the Second Amended and Restated Credit Agreement, dated as of April 25, 1997 (the "Credit Agreement"), among Sybron International Corporation, a Wisconsin corporation (the "Parent"), Ormco Corporation, a Delaware corporation ("Ormco"), Kerr Corporation, a Delaware corporation ("Kerr"), Nalge Nunc International Corporation, a Delaware corporation ("NNI"), Erie Scientific Company, a Delaware corporation ("Erie"), Barnstead Thermolyne Corporation, a Delaware corporation ("Barnstead"; Ormco, Kerr, NNI, Erie and Barnstead are collectively referred to herein as the "Subsidiary Borrowers"), the several banks and other financial institutions from time to time parties thereto (the "Lenders"), Chase Securities Inc., as Arranger, and The Chase Manhattan Bank, a New York banking corporation, as administrative agent for the Lenders thereunder (in such capacity, the "Administrative Agent"). W I T N E S S E T H: WHEREAS, pursuant to the Credit Agreement, the Lenders have agreed to make, and have made, certain loans and other extensions of credit to the Parent and the Subsidiary Borrowers; and WHEREAS, the Parent and the Subsidiary Borrowers have requested, and, upon this Amendment becoming effective, the Lenders have agreed, that certain provisions of the Credit Agreement be amended in the manner provided for in this Amendment. NOW, THEREFORE, the parties hereto hereby agree as follows: I. Defined Terms. Terms defined in the Credit Agreement and used herein shall have the meanings given to them in the Credit Agreement. II. Amendments to Credit Agreement. Section 7 is hereby amended by deleting paragraph (b) of subsection 7.1 thereof in its entirety and substituting in lieu thereof the following: "(b) Interest Coverage Ratio. Permit the Interest Coverage Ratio for any period of four consecutive fiscal quarters ending during any period set forth below to be less than the ratio set forth opposite such period below: Date Ratio ---- ----- 6/30/98 - 6/29/99 3.25 6/30/99 - thereafter 4.00 III. Conditions to Effectiveness. This Amendment shall become effective on the date (the "Amendment Effective Date") on which the Parent, the Subsidiary Borrowers, the Administrative Agent and the Majority Lenders shall have executed and delivered to the Administrative Agent this Amendment. 2 2 IV. General. 1. Representation and Warranties. To induce the Administrative Agent and the Lenders parties hereto to enter into this Amendment, the Parent and the Subsidiary Borrowers hereby represent and warrant to the Administrative Agent and all of the Lenders as of the Amendment Effective Date that the representations and warranties made by the Loan Parties in the Loan Documents are true and correct in all material respects on and as of the Amendment Effective Date, before and after giving effect to the effectiveness of this Amendment, as if made on and as of the Amendment Effective Date and no Default or Event of Default shall have occurred and be continuing. 2. Payment of Expenses. The Parent and the Subsidiary Borrowers agree to pay or reimburse the Administrative Agent for all of its out-of-pocket costs and reasonable expenses incurred in connection with this Amendment, any other documents prepared in connection herewith and the transactions contemplated hereby, including, without limitation, the reasonable fees and disbursements of counsel to the Administrative Agent. 3. No Other Amendments; Confirmation. Except as expressly amended, modified and supplemented hereby, the provisions of the Credit Agreement and the Notes are and shall remain in full force and effect. This Amendment shall constitute a Loan Document. The Lenders hereby waive any Default that shall have occurred between June 30, 1998 and the date hereof in respect of Section 7.1(b). 4. Governing Law; Counterparts. (a) This Amendment and the rights and obligations of the parties hereto shall be governed by, and construed and interpreted in accordance with, the laws of the State of New York. (b) This Amendment may be executed by one or more of the parties to this Agreement on any number of separate counterparts, and all of said counterparts taken together shall be deemed to constitute one and the same instrument. This Amendment may be delivered by facsimile transmission of the relevant signature pages hereof. 3 3 IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed and delivered by their respective proper and duly authorized officers as of the day and year first above written. SYBRON INTERNATIONAL CORPORATION By: ------------------------------- Title: ORMCO CORPORATION By: ------------------------------- Title: KERR CORPORATION By: ------------------------------- Title: NALGE NUNC INTERNATIONAL CORPORATION By: ------------------------------- Title: ERIE SCIENTIFIC COMPANY By: ------------------------------- Title: 4 4 BARNSTEAD THERMOLYNE CORPORATION By: ------------------------------- Title: THE CHASE MANHATTAN BANK, as Administrative Agent and as a Lender By: ------------------------------- Title: ABN AMRO BANK N.V. By: ------------------------------- Title: By: ------------------------------- Title: BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION By: ------------------------------- Title: BANK OF MONTREAL By: ------------------------------- Title: 5 5 BANK ONE, WISCONSIN By: ------------------------------- Title: THE BANK OF NOVA SCOTIA By: ------------------------------- Title: BANK OF SCOTLAND By: ------------------------------- Title: NATEXIS BANQUE/BFCE By: ------------------------------- Title: By: ------------------------------- Title: 6 6 PARIBAS By: ------------------------------- Title: By: ------------------------------- Title: CREDIT AGRICOLE INDOSUEZ By: ------------------------------- Title: COMERICA BANK By: ------------------------------- Title: CREDIT LYONNAIS CHICAGO BRANCH By: ------------------------------- Title: 7 7 DG BANK DEUTSCHE GENOSSENSCHAFTSBANK CAYMAN ISLAND BRANCH By: ------------------------------- Title: By: ------------------------------- Title: U.S. BANK NATIONAL ASSOCIATION By: ------------------------------- Title: FLEET NATIONAL BANK By: ------------------------------- Title: THE FUJI BANK, LIMITED By: ------------------------------- Title: THE LONG-TERM CREDIT BANK OF JAPAN, LTD. By: ------------------------------- Title: 8 8 MELLON BANK, N.A. By: ------------------------------- Title: THE BANK OF TOKYO-MITSUBISHI, LTD., CHICAGO BRANCH By: ------------------------------- Title: THE MITSUBISHI TRUST AND BANKING CORPORATION By: ------------------------------- Title: THE FIRST NATIONAL BANK OF CHICAGO By: ------------------------------- Title: THE SAKURA BANK, LIMITED By: ------------------------------- Title: 9 9 SOCIETE GENERALE By: ------------------------------- Title: By: ------------------------------- Title: THE SUMITOMO BANK, LTD. CHICAGO BRANCH By: ------------------------------- Title: THE BANK OF NEW YORK By: ------------------------------- Title: THE SANWA BANK, LIMITED By: ------------------------------- Title: 10 10 BANQUE NATIONALE DE PARIS CHICAGO BRANCH By: ------------------------------- Title: BHF BANK AKTIENGESELLSCHAFT GRAND CAYMAN BRANCH By: ------------------------------- Title: By: ------------------------------- Title: FIRST UNION NATIONAL BANK By: ------------------------------- Title: FIRSTAR BANK MILWAUKEE, N.A. By: ------------------------------- Title: THE INDUSTRIAL BANK OF JAPAN, LIMITED CHICAGO BRANCH By: ------------------------------- Title: 11 11 BANCA COMMERCIALE ITALIANA CHICAGO BRANCH By: ------------------------------- Title: By: ------------------------------- Title: BANK HAPOALIM, B.M. PHILADELPHIA BRANCH By: ------------------------------- Title: By: ------------------------------- Title: