##### 



Exhibit 99.1

THIRD AMENDMENT TO LOAN DOCUMENTS

This Third Amendment To Loan Documents, dated December 13, 2002, is
entered into between Congress Financial Corporation (Western) (Lender) and
Zila, Inc., Zila Pharmaceuticals, Inc., Ryker Dental of Kentucky, Inc. and
Inter-Cal Corporation, Inc. (collectively, the Borrower).

The parties agree to amend the Loan and Security Agreement between them,
dated August 17, 2001 (as amended from time to time, the Loan Agreement),
effective on the date hereof (except where otherwise provided below). (This
Amendment, the Loan Agreement, any prior written amendments thereto signed by
Lender and the Borrower, and all other written documents and agreements between
Lender and the Borrower are referred to herein collectively as the Loan
Documents. Capitalized terms used but not defined in this Amendment shall
have the meanings set forth in the Loan Agreement.)

1.     Modified Adjusted Tangible Net Worth.Effective as of October 1, 2002,
the Adjusted Tangible Net Worth covenant set forth in Section 9.17 of the Loan
Agreement is hereby amended to read as follows:



| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | 9.17 Adjusted Tangible Net Worth. Zila, on a consolidated
basis, shall, at all times, maintain Adjusted Tangible Net
Worth of not less than $12,000,000, provided that, the
amount of such minimum Adjusted Tangible Net Worth shall be
increased, or decreased, by the amount of any net gain, or
net loss, respectively, resulting from any sale to a third
party of 100% of the stock or all or substantially all of
the assets of any of the following: Zila, ZP, Ryker Dental,
or Inter-Cal.

2.     EBITDA Covenant.On or before January 17, 2003, Borrower will provide
Lender, in form acceptable to Lender, Borrowers forecast of its projected
income and expenses for the 2003 calendar year and such additional information
as may be requested by Lender, from which there must be prepared and executed,
on or prior to February 1, 2003, an EBITDA covenant in form and substance
acceptable to Lender. When executed, the EBITDA covenant will be substituted
in place and stead of the Modified Adjusted Tangible Net Worth covenant
contained in paragraph 9.17 of the Loan Agreement. Failure to timely execute
and deliver the EBITDA covenant shall constitute an Event of Default under this
Loan Agreement.

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| |  |          |  |                                  
| |  | -------- |  | ---------------------------------
| |  | Congress |  | Third Amendment to Loan Documents

3.     Fee.In consideration for Lender entering into this Amendment,
Borrower shall concurrently pay Lender a fee in the amount of $     N.A.     , which
shall be non-refundable and in addition to all interest and all other fees and
charges, and which may be charged to Borrowers loan account.

4.     Representations True.Borrower represents and warrants to Lender that
all representations and warranties set forth in the Loan Agreement, as amended
hereby, are true and correct.

5.     General Provisions.This Amendment, the Loan Agreement, and the other
Loan Documents set forth in full all of the representations and agreements of
the parties with respect to the subject matter hereof and supersede all prior
discussions, representations, agreements and understandings between the parties
with respect to the subject hereof. Except as herein expressly amended, all of
the terms and provisions of the Loan Agreement and the other Loan Documents
shall continue in full force and effect and the same are hereby ratified and
confirmed.

|                           |  |                                          |  |        |  |                  |  |  |  | 
|-------------------------- |  | ---------------------------------------- |  | ------ |  | ---------------- |  |  |  | 
|Borrower:                  |  | Lender:                                 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|ZILA, INC.                 |  | Congress Financial Corporation (Western)
|                           |  |                                          |  |        |  |                  |  |  |  | 
|By:                        |  | /s/ Bradley C. Anderson                  |  | By:    |  | /s/ Craig Taylor |  |  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|                           |  | President or Vice President              |  | Title: |  | Vice President   |  |  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|By:                        |  | /s/ Bradley C. Anderson                  |  |        |  |                  |  |  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|                           |  | Secretary or Asst Secretary             |  |        |  |                  |  |  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|ZILA PHARMACEUTICALS, INC. |  |                                          |  |        |  |                  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|By:                        |  | /s/ Bradley C. Anderson                  |  |        |  |                  |  |  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|                           |  | President or Vice President              |  |        |  |                  |  |  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|By:                        |  | /s/ Bradley C. Anderson                  |  |        |  |                  |  |  |  | 
|                           |  |                                          |  |        |  |                  |  |  |  | 
|                           |  | Secretary or Asst Secretary             |  |        |  |                  |  |  |  | 

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| |  |          |  |                                  
| |  | -------- |  | ---------------------------------
| |  | Congress |  | Third Amendment to Loan Documents

|                               |  |                              |  | 
|------------------------------ |  | ---------------------------- |  | 
|RYKER DENTAL OF KENTUCKY, INC. |  |                             
|                               |  |                              |  | 
|By:                            |  | /s/ Bradley C. Anderson      |  | 
|                               |  |                              |  | 
|                               |  | President or Vice President  |  | 
|                               |  |                              |  | 
|By:                            |  | /s/ Bradley C. Anderson      |  | 
|                               |  |                              |  | 
|                               |  | Secretary or Asst Secretary |  | 
|                               |  |                              |  | 
|INTER-CAL CORPORATION, INC.    |  |                             
|                               |  |                              |  | 
|By:                            |  | /s/ Bradley C. Anderson      |  | 
|                               |  |                              |  | 
|                               |  | President or Vice President  |  | 
|                               |  |                              |  | 
|By:                            |  | /s/ Bradley C. Anderson      |  | 
|                               |  |                              |  | 
|                               |  | Secretary or Asst Secretary |  | 

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##### 



| |  |          |  |                                  
| |  | -------- |  | ---------------------------------
| |  | Congress |  | Third Amendment to Loan Documents

CONSENT

The undersigned, guarantors, acknowledge that their consent to the
foregoing First Amendment to Loan Documents is not required, but the
undersigned nevertheless do hereby consent to the foregoing First Amendment to
Loan Documents and to the documents and agreements referred to therein and to
all future modifications and amendments thereto, and any termination thereof,
and to any and all other present and future documents and agreements between or
among the foregoing parties. Nothing herein shall in any way limit any of the
terms or provisions of the Continuing Guarantees of the undersigned, all of
which are hereby ratified and affirmed. This Consent may be executed in
counterparts. The signatures of the undersigned shall be fully effective even
if other persons named below fail to sign this Consent.

|                                    |  |                              |  |     |  |                              |  |  |  | 
|----------------------------------- |  | ---------------------------- |  | --- |  | ---------------------------- |  |  |  | 
|Zila, Inc.                          |  | Zila Pharmaceuticals, Inc.  
|                                    |  |                              |  |     |  |                              |  |  |  | 
|By:                                 |  | /s/ Bradley C. Anderson      |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|                                    |  | President or Vice President  |  |     |  | President or Vice President  |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|By:                                 |  | /s/ Bradley C. Anderson      |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|                                    |  | Secretary or Asst Secretary |  |     |  | Secretary or Asst Secretary |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|Bio-Dental Technologies Corporation |  | Zila Technologies, Inc.     
|                                    |  |                              |  |     |  |                              |  |  |  | 
|By:                                 |  | /s/ Bradley C. Anderson      |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|                                    |  | President or Vice President  |  |     |  | President or Vice President  |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|By:                                 |  | /s/ Bradley C. Anderson      |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|                                    |  | Secretary or Asst Secretary |  |     |  | Secretary or Asst Secretary |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|Oxycal Laboratories, Incorporated   |  | Zila limited, Inc.          
|                                    |  |                              |  |     |  |                              |  |  |  | 
|By:                                 |  | /s/ Bradley C. Anderson      |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|                                    |  | President or Vice President  |  |     |  | President or Vice President  |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|By:                                 |  | /s/ Bradley C. Anderson      |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                    |  |                              |  |     |  |                              |  |  |  | 
|                                    |  | Secretary or Asst Secretary |  |     |  | Secretary or Asst Secretary |  |  |  | 

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##### 



| |  |          |  |                                  
| |  | -------- |  | ---------------------------------
| |  | Congress |  | Third Amendment to Loan Documents

|                                     |  |                                |  |     |  |                              |  |  |  | 
|------------------------------------ |  | ------------------------------ |  | --- |  | ---------------------------- |  |  |  | 
|Zila Swab Technologies, Inc.         |  | Ryker Dental of Kentucky, Inc.
|                                     |  |                                |  |     |  |                              |  |  |  | 
|By:                                  |  | /s/ Bradley C. Anderson        |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|                                     |  | President or Vice President    |  |     |  | President or Vice President  |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|By:                                  |  | /s/ Bradley C. Anderson        |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|                                     |  | Secretary or Asst Secretary   |  |     |  | Secretary or Asst Secretary |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|Integrated Dental Technologies, Inc. |  | Inter-Cal Corporation, Inc.   
|                                     |  |                                |  |     |  |                              |  |  |  | 
|By:                                  |  | /s/ Bradley C. Anderson        |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|                                     |  | President or Vice President    |  |     |  | President or Vice President  |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|By:                                  |  | /s/ Bradley C. Anderson        |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|                                     |  | Secretary or Asst Secretary   |  |     |  | Secretary or Asst Secretary |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|Zila International, Inc.             |  | Zila Acquisition Corp.        
|                                     |  |                                |  |     |  |                              |  |  |  | 
|By:                                  |  | /s/ Bradley C. Anderson        |  | By: |  | /s/Bradley C. Anderson       |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|                                     |  | President or Vice President    |  |     |  | President or Vice President  |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|By:                                  |  | /s/ Bradley C. Anderson        |  | By: |  | /s/ Bradley C. Anderson      |  |  |  | 
|                                     |  |                                |  |     |  |                              |  |  |  | 
|                                     |  | Secretary or Asst Secretary   |  |     |  | Secretary or Asst Secretary |  |  |  | 

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