EXHIBIT 99.3 FOURTH EXTENSION AND MODIFICATION AGREEMENT By this FOURTH EXTENSION AND MODIFICATION AGREEMENT (this "Agreement"), dated as of June 6, 2002 (the "Effective Date"), RYKER DENTAL OF KENTUCKY, INC. ("Lender"), PRACTICEWARES, INC....Fourth Extension and Modification Agreement • July 3rd, 2002 • Zila Inc • Wholesale-medical, dental & hospital equipment & supplies • Arizona
