(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2004/0112894 Al
Varma (43) Pub. Date: Jun. 17,2004
(54) MICROWAVE-ASSISTED STEAM STERILIZATION OF DENTAL AND SURGICAL INSTRUMENTS
(76) Inventor: Ravi Varma, Louisville, CO (US)
COCHRAN FREUND & YOUNG LLC
3555 STANFORD ROAD
FORT COLLINS, CO 80525 (US)
(21) Appl. No.: 10/675,876
(22) Filed: Sep. 29, 2003
Related U.S. Application Data
(63) Continuation-in-part of application No. 10/071,340, filed on Feb. 8, 2002, now Pat. No. 6,646,241.
(51) Int. CI.7 A61L 2/00; H05B 6/64
(52) U.S. CI 219/679; 422/21
A surgical and dental instrument sterilizer is described. Liquid water is rapidly vaporized by microwave heating and steam is generated to attain a steam pressure of approximately 47 psi and a temperature of approximately 135° C. in the region of the articles to be sterilized. Micron-size waterdroplets are intermittently sprayed onto the articles which are arranged on a tray, from both the top and from underneath thereof so as to thoroughly wet the surfaces. A 30-90 s duration of droplet spray is followed by pulsed microwave irradiation of the top and underneath surfaces for a similar period, as an example; this is followed by a plurality of spray/microwave cycles. Sterilizing conditions in the sterilizer chamber are maintained in the presence of the water spray/microwave flashing cycles since introducing small aliquots of water will not affect the desired sterilizing condition provided by superheated steam augmented by microwave radiation necessary to kill microbes including spores; however arcing from metal instruments when subjected to microwave radiation is substantially reduced.