<PAGE>   1
                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                   FORM 10-Q/A

                                 AMENDMENT NO. 1
                                       TO

[X] Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange
    Act of 1934 For the quarterly period ended December 31, 1997

                                                      or

[  ] Transition Report Pursuant to Section 13 or 15(d) of the Securities 
     Exchange Act of 1934 For the transition period from __________to_________

Commission File Number: 1-11091

                        SYBRON INTERNATIONAL CORPORATION
             (Exact name of registrant as specified in its charter)

                   Wisconsin                                   22-2849508
         (State or other jurisdiction of                   (I.R.S. Employer
          incorporation or organization)                    Identification No.)

411 East Wisconsin Avenue, Milwaukee, Wisconsin                53202
     (Address of principal executive offices)                (Zip Code)

                                 (414) 274-6600
              (Registrant's telephone number, including area code)

(Former name, former address and former fiscal year, if changed since last
report.)

         Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes X   No 
                                             ----    ----
         At February 9, 1998 there were 97,191,300 shares of the Registrant's
Common Stock, par value $0.01 per share, outstanding. The number of outstanding
shares has been adjusted to reflect a two-for-one stock split in the form of a
100 percent stock dividend (one share of Common Stock for each outstanding share
of Common Stock), to be distributed on February 20, 1998 to shareholders of
record at the close of business on February 12, 1998.

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         The undersigned registrant hereby amends the following items, financial
statements, exhibits or other portions of its Quarterly Report on Form 10-Q for
the quarter ended December 31, 1997:

                           PART II - OTHER INFORMATION

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

     (a)   EXHIBITS:

           See the Exhibit Index following the Signature page in this report,
           which is incorporated herein by reference.

     (b)   REPORTS ON FORM 8-K:

           No reports on Form 8-K were filed during the quarter for which this
           report is filed.



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                                   SIGNATURES


         Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this amendment to be signed on its behalf by the
undersigned thereunto duly authorized.


                                               SYBRON INTERNATIONAL CORPORATION
                                               (Registrant)



Date  May 22, 1998                             /s/ Dennis Brown
      ------------                             ----------------
                                               Dennis Brown
                                               Vice President - Finance, Chief
                                               Financial Officer & Treasurer*



                                               * executing as both the 
                                                 principal financial officer 
                                                 and the duly authorized 
                                                 officer of the Company.










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                        SYBRON INTERNATIONAL CORPORATION
                               (THE "REGISTRANT")
                          (COMMISSION FILE NO. 1-11091)

                                  EXHIBIT INDEX
                                       TO
      QUARTERLY REPORT ON FORM 10-Q FOR THE QUARTER ENDED DECEMBER 31, 1997


<TABLE>
<CAPTION>

                                                                INCORPORATED
EXHIBIT                                                         HEREIN BY                FILED
NUMBER          DESCRIPTION                                     REFERENCE TO             HEREWITH
<S>            <C>                                              <C>                     <C>
 11            Statement re Computation of Per Share                                       X
               Earnings


 27.1          Restated Financial Data Schedule                                            X*

 27.2          Restated Financial Data                                                     X*
               Schedule (three month
               period ended December 31,
               1996)

</TABLE>
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*   Filed with Amendment No. 1