1. Chapter 21 Principals and Techniques of Sterilization Copyright 2003, Elsevier Science (USA). All rights reserved. No part of this product may be reproduced or transmitted in any form or by any means, electronic or mechanical, including input into or storage in any information system, without permission in writing from the publisher. PowerPoint ® presentation slides may be displayed and may be reproduced in print form for instructional purposes only, provided a proper copyright notice appears on the last page of each print-out. Produced in the United States of America ISBN 0-7216-9770-4

2. Copyright 2003, Elsevier Science (USA). All rights reserved. Introduction One of the most important responsibilities of the dental assistant is to process contaminated instruments for reuse. Instrument processing involves much more than sterilization. Sterilization is a process intended to kill all microorganisms and is the highest level of microbial destruction. One of the most important responsibilities of the dental assistant is to process contaminated instruments for reuse. Instrument processing involves much more than sterilization. Sterilization is a process intended to kill all microorganisms and is the highest level of microbial destruction.

3. Copyright 2003, Elsevier Science (USA). All rights reserved. Table 21-1 Seven Steps of Instrument Processing. Table 21-1

4. Copyright 2003, Elsevier Science (USA). All rights reserved. Classification of Instruments and Equipment n Instruments and equipment are divided into three classifications: Critical Semicritical Noncritical n The classifications are used to determine the minimal type of posttreatment processing. n Instruments and equipment are divided into three classifications: Critical Semicritical Noncritical n The classifications are used to determine the minimal type of posttreatment processing.

5. Copyright 2003, Elsevier Science (USA). All rights reserved. Critical Instruments  Critical instruments must be heat sterilized before reuse. Critical items are surgical and other instruments used to penetrate soft tissue or bone; examples of critical instruments include forceps, scalpels, bone chisels, scalers, and burs.

6. Copyright 2003, Elsevier Science (USA). All rights reserved. Semicritical Instruments n Semicritical instruments are those that come in contact with the oral tissues but do not penetrate soft tissue or bone; examples include plastic- handled brushes, high volume oral evacuator (HVE) tips, and amalgam carriers. n Semicritical instruments should be heat sterilized before reuse. If this is not possible (because the instrument will be damaged by heat), the instrument should receive, at a minimum, high- level disinfection. n Semicritical instruments are those that come in contact with the oral tissues but do not penetrate soft tissue or bone; examples include plastic- handled brushes, high volume oral evacuator (HVE) tips, and amalgam carriers. n Semicritical instruments should be heat sterilized before reuse. If this is not possible (because the instrument will be damaged by heat), the instrument should receive, at a minimum, high- level disinfection.

7. Copyright 2003, Elsevier Science (USA). All rights reserved. Noncritical Items n Noncritical items should be processed with an intermediate or low-level disinfectant after each patient use. n Noncritical clinical items are devices such as the position indicator device (PID) of the x-ray unit tube head or the lead apron that comes into contact only with intact skin. n Noncritical items should be processed with an intermediate or low-level disinfectant after each patient use. n Noncritical clinical items are devices such as the position indicator device (PID) of the x-ray unit tube head or the lead apron that comes into contact only with intact skin.

8. Copyright 2003, Elsevier Science (USA). All rights reserved. Personal Protective Equipment  You must always use personal protective equipment, including utility gloves, mask, and protective eyewear and clothing, when processing instruments.

9. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-1 Personal protective equipment must be worn while preparing instruments for sterilization. Fig. 21-1

10. Copyright 2003, Elsevier Science (USA). All rights reserved. Instrument Processing Area n The instrument processing area, or sterilization area, should be centrally located in the dental office. n The “ideal” instrument processing area should be dedicated only to instrument processing. n It should have good air circulation to control the heat generated by the sterilizers. The size of the area should accommodate all the equipment and supplies necessary for instrument processing. n There should be a deep sink with hands-free controls for instrument rinsing. n The instrument processing area, or sterilization area, should be centrally located in the dental office. n The “ideal” instrument processing area should be dedicated only to instrument processing. n It should have good air circulation to control the heat generated by the sterilizers. The size of the area should accommodate all the equipment and supplies necessary for instrument processing. n There should be a deep sink with hands-free controls for instrument rinsing.

11. Copyright 2003, Elsevier Science (USA). All rights reserved. Instrument Processing Area  cont’d n The flooring should be an uncarpeted seamless hard surface. n The size, shape, and accessories of the instrument processing area will vary from one dental office to another. n The flooring should be an uncarpeted seamless hard surface. n The size, shape, and accessories of the instrument processing area will vary from one dental office to another.

12. Copyright 2003, Elsevier Science (USA). All rights reserved. Basic Principles for Work Flow Pattern n Processing instruments should proceed in a single loop, from dirty through clean to sterile, without ever doubling back. n If the instrument processing area is small, you can use signs to separate the contaminated and clean areas. n This method works well to prevent mixing of contaminated and sterile items in a small sterilization area. n Processing instruments should proceed in a single loop, from dirty through clean to sterile, without ever doubling back. n If the instrument processing area is small, you can use signs to separate the contaminated and clean areas. n This method works well to prevent mixing of contaminated and sterile items in a small sterilization area.

13. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-2 A, Linear flow pattern. B,“U” shaped instrument processing area. Fig. 21-2

14. Copyright 2003, Elsevier Science (USA). All rights reserved. Contaminated Area n All soiled instruments are brought into the contaminated area. n Any disposable items not already discarded in the treatment room are disposed of as contaminated waste. n The contaminated area contains clean protective eyewear and utility gloves, counter space, a sink, a waste disposal container, holding solution, ultrasonic cleaner, eyewash station, and supplies for wrapping instruments before sterilization. n Note: Soiled and clean instruments are never stored in the same cabinet. n All soiled instruments are brought into the contaminated area. n Any disposable items not already discarded in the treatment room are disposed of as contaminated waste. n The contaminated area contains clean protective eyewear and utility gloves, counter space, a sink, a waste disposal container, holding solution, ultrasonic cleaner, eyewash station, and supplies for wrapping instruments before sterilization. n Note: Soiled and clean instruments are never stored in the same cabinet.

15. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-3 Waste items are properly discarded. Fig. 21-3

16. Copyright 2003, Elsevier Science (USA). All rights reserved. Instrument Processing Procedures n Holding solution If the instruments cannot be cleaned immediately after the procedure, they should be placed in a holding solution to prevent the drying of blood and debris on the instruments. n Precleaning instruments Hand scrubbing Ultrasonic cleaning Instrument washing machines n Holding solution If the instruments cannot be cleaned immediately after the procedure, they should be placed in a holding solution to prevent the drying of blood and debris on the instruments. n Precleaning instruments Hand scrubbing Ultrasonic cleaning Instrument washing machines

17. Copyright 2003, Elsevier Science (USA). All rights reserved. Ultrasonic Cleaning n Used to loosen and remove debris from instruments and reduce the potential of hand injuries from cuts and punctures during the cleaning process. n Puncture-resistant utility gloves, a mask, protective eyewear, and a protective gown should always be worn when using the ultrasonic cleaner. n The ultrasonic cleaner works by producing sound waves, which are beyond the range of human hearing. The time may vary from 5 to 15 minutes, depending on the amount and type of material on the instruments, and the efficiency of the ultrasonic unit. n Used to loosen and remove debris from instruments and reduce the potential of hand injuries from cuts and punctures during the cleaning process. n Puncture-resistant utility gloves, a mask, protective eyewear, and a protective gown should always be worn when using the ultrasonic cleaner. n The ultrasonic cleaner works by producing sound waves, which are beyond the range of human hearing. The time may vary from 5 to 15 minutes, depending on the amount and type of material on the instruments, and the efficiency of the ultrasonic unit.

18. Copyright 2003, Elsevier Science (USA). All rights reserved. Ultrasonic Cleaning Solutions n Use ONLY the ultrasonic solutions that are specially formulated for use in the ultrasonic cleaner. n DO NOT use other chemicals such as plain disinfectants in the ultrasonic cleaner. n Specific ultrasonic solutions are available that remove difficult materials, such as cements, tartar, stains, plaster, and alginate. n The ultrasonic cleaning unit should be labeled with both a chemical label and a biohazard label because it contains a chemical and contaminated instruments. n Use ONLY the ultrasonic solutions that are specially formulated for use in the ultrasonic cleaner. n DO NOT use other chemicals such as plain disinfectants in the ultrasonic cleaner. n Specific ultrasonic solutions are available that remove difficult materials, such as cements, tartar, stains, plaster, and alginate. n The ultrasonic cleaning unit should be labeled with both a chemical label and a biohazard label because it contains a chemical and contaminated instruments.

19. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-5 Commercial solutions are available for use in precleaning. (Courtesy Biotrol International.) Fig. 21-5

20. Copyright 2003, Elsevier Science (USA). All rights reserved. Testing the Ultrasonic Cleaner n Hold a 5-inch x 5-inch sheet of lightweight aluminum foil vertically (like a curtain) half-submerged in the (fresh unused) solution. n Run the unit for 20 seconds, and then hold the foil up toward the light. n The surfaces that were submerged into the solution should be evenly marked with a tiny pebbling effect over the entire surface. n An area on the foil that is greater than 1 / 2 inch without pebbling indicates that there is a problem with the unit and it needs servicing by the manufacturer. n Hold a 5-inch x 5-inch sheet of lightweight aluminum foil vertically (like a curtain) half-submerged in the (fresh unused) solution. n Run the unit for 20 seconds, and then hold the foil up toward the light. n The surfaces that were submerged into the solution should be evenly marked with a tiny pebbling effect over the entire surface. n An area on the foil that is greater than 1 / 2 inch without pebbling indicates that there is a problem with the unit and it needs servicing by the manufacturer.

21. Copyright 2003, Elsevier Science (USA). All rights reserved. Automated Instrument Washers / Disinfectors n Automated instrument washers/disinfectors look and work very much like a household dishwasher. n They must be approved by the U.S. Food and Drug Administration (FDA) for use with dental instruments. n These units use a combination of very hot water recirculation and detergents to remove organic material, and then instruments are automatically dried. n They have a disinfecting cycle that subjects the instruments to a level of heat that kills most vegetative microorganisms. n Instruments processed in the automatic instrument washers/disinfectors must be wrapped and sterilized before use on a patient. n Automated instrument washers/disinfectors look and work very much like a household dishwasher. n They must be approved by the U.S. Food and Drug Administration (FDA) for use with dental instruments. n These units use a combination of very hot water recirculation and detergents to remove organic material, and then instruments are automatically dried. n They have a disinfecting cycle that subjects the instruments to a level of heat that kills most vegetative microorganisms. n Instruments processed in the automatic instrument washers/disinfectors must be wrapped and sterilized before use on a patient.

22. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-10 Miele thermal disinfector. Fig. 21-10

23. Copyright 2003, Elsevier Science (USA). All rights reserved. Drying, Lubrication, and Corrosion Control n Instruments and burs made of carbon steel can rust during steam sterilization. n Rust inhibitors are available as a spray or dip solution and help reduce rust and corrosion. n An alternative to rust inhibitors is to thoroughly dry the instrument and use dry heat or unsaturated chemical vapor sterilization, which do not cause rusting. n Hinged instruments may need to be lubricated to maintain proper opening. n Instruments and burs made of carbon steel can rust during steam sterilization. n Rust inhibitors are available as a spray or dip solution and help reduce rust and corrosion. n An alternative to rust inhibitors is to thoroughly dry the instrument and use dry heat or unsaturated chemical vapor sterilization, which do not cause rusting. n Hinged instruments may need to be lubricated to maintain proper opening.

24. Copyright 2003, Elsevier Science (USA). All rights reserved. Packaging Instruments n Before sterilization, the instruments must be wrapped or packaged to protect them from becoming contaminated after sterilization. n When instruments are sterilized without being packaged, they are immediately exposed to the environment as soon as the sterilizer door is opened. n An additional advantage to packaging instruments is that they can be packaged into special setups (e.g., crown and bridge, amalgam, composite). n Before sterilization, the instruments must be wrapped or packaged to protect them from becoming contaminated after sterilization. n When instruments are sterilized without being packaged, they are immediately exposed to the environment as soon as the sterilizer door is opened. n An additional advantage to packaging instruments is that they can be packaged into special setups (e.g., crown and bridge, amalgam, composite).

25. Copyright 2003, Elsevier Science (USA). All rights reserved. Packaging Materials n Sterilization packaging materials and cassettes are medical devices and therefore must be approved by the FDA. n Use only products and materials that are labeled as sterilization packaging. n There are specific types of packaging material for each method of sterilization. n Never use safety pins, staples, paper clips, or any other sharp objects that could penetrate the packaging material. n Sterilization packaging materials and cassettes are medical devices and therefore must be approved by the FDA. n Use only products and materials that are labeled as sterilization packaging. n There are specific types of packaging material for each method of sterilization. n Never use safety pins, staples, paper clips, or any other sharp objects that could penetrate the packaging material.

26. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-11 Self-seal packages provide an excellent wrap. (Courtesy SPSMedical.) Fig. 21-11

27. Copyright 2003, Elsevier Science (USA). All rights reserved. Sterilization Monitoring n It is critical that dental instruments are properly sterilized. n There are three forms of sterilization monitoring: Chemical Physical monitoring Biologic n All three processes are unique, have different functions, and must be used consistently to assure sterility. n It is critical that dental instruments are properly sterilized. n There are three forms of sterilization monitoring: Chemical Physical monitoring Biologic n All three processes are unique, have different functions, and must be used consistently to assure sterility.

28. Copyright 2003, Elsevier Science (USA). All rights reserved. Chemical Monitoring n Involves the use of heat-sensitive chemical that changes color when they are exposed to certain conditions. n The two types of chemical indicators are: Process indicators are placed on the outside of the instrument packages before sterilization. They respond to heat only. Process integrators are placed inside instrument packages, and they respond to a combination of steam and temperature and time. n Involves the use of heat-sensitive chemical that changes color when they are exposed to certain conditions. n The two types of chemical indicators are: Process indicators are placed on the outside of the instrument packages before sterilization. They respond to heat only. Process integrators are placed inside instrument packages, and they respond to a combination of steam and temperature and time.

29. Copyright 2003, Elsevier Science (USA). All rights reserved. n Process indicators and integrators provide immediate, visual control of sterilizing conditions, but they do not indicate sterility and are not a replacement for biologic monitoring. Chemical Monitoring  cont’d

30. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-12 A, Unprocessed instruments. B, Wrapped instruments following processing. Note the color change in the tape. Fig. 21-12

31. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-13 The process integrator is placed inside the instrument package. (Courtesy of SPSMedical.) Fig. 21-13

32. Copyright 2003, Elsevier Science (USA). All rights reserved. Physical Monitoring n Involves physically looking at the gauges and readings on the sterilizer and recording the temperatures, pressure, and exposure time. n Although correct readings do not guarantee sterilization, an incorrect reading gives you the first signal that something is wrong. n The temperature recorded is for the chamber, not the inside of the pack. n Problems with overloading or improper packaging would not be detected from the reading on the gauges. n Involves physically looking at the gauges and readings on the sterilizer and recording the temperatures, pressure, and exposure time. n Although correct readings do not guarantee sterilization, an incorrect reading gives you the first signal that something is wrong. n The temperature recorded is for the chamber, not the inside of the pack. n Problems with overloading or improper packaging would not be detected from the reading on the gauges.

33. Copyright 2003, Elsevier Science (USA). All rights reserved. Biologic Monitoring n Biologic monitoring is the best way to determine if sterilization has occurred. n The CDC, ADA, and Organization for Safety and Asepsis Procedures (OSAP) recommend at least weekly biologic monitoring of sterilization equipment. n Several states also require routine biologic monitoring. n In addition to the recommended weekly biologic monitoring, there are other times when biologic monitoring (also known as spore testing) should be done. n Biologic monitoring is the best way to determine if sterilization has occurred. n The CDC, ADA, and Organization for Safety and Asepsis Procedures (OSAP) recommend at least weekly biologic monitoring of sterilization equipment. n Several states also require routine biologic monitoring. n In addition to the recommended weekly biologic monitoring, there are other times when biologic monitoring (also known as spore testing) should be done.

34. Copyright 2003, Elsevier Science (USA). All rights reserved. Other Times to Spore Test n After the sterilizer has been serviced, to verify proper functioning. n When you change packaging materials, to be sure the sterilizing agent is reaching the instruments. n After an electric or power source failure, to verify proper functioning of the sterilizer. n After training new employees, to be sure they are following proper procedures. n For all cycles that contain any device to be implanted. n After the sterilizer has been serviced, to verify proper functioning. n When you change packaging materials, to be sure the sterilizing agent is reaching the instruments. n After an electric or power source failure, to verify proper functioning of the sterilizer. n After training new employees, to be sure they are following proper procedures. n For all cycles that contain any device to be implanted.

35. Copyright 2003, Elsevier Science (USA). All rights reserved. Biologic Indicators n Also known as spore tests, biologic indicators are vials or strips of paper that contain harmless bacterial spores (spores are highly resistant to heat). n Three biological indicators are used. Two biologic indicators (BIs) are placed inside instrument packs, and the sterilizer is operated under normal conditions. The third strip is set aside as a control. n If the spores survive the sterilization cycle (a positive culture), there has been a sterilization failure. If the spores are killed (a negative culture), the sterilization cycle was successful. n Also known as spore tests, biologic indicators are vials or strips of paper that contain harmless bacterial spores (spores are highly resistant to heat). n Three biological indicators are used. Two biologic indicators (BIs) are placed inside instrument packs, and the sterilizer is operated under normal conditions. The third strip is set aside as a control. n If the spores survive the sterilization cycle (a positive culture), there has been a sterilization failure. If the spores are killed (a negative culture), the sterilization cycle was successful.

36. Copyright 2003, Elsevier Science (USA). All rights reserved. n The culturing of the spore test is usually handled through the use of a mail-in monitoring service. n The culture can also be done in the dental office. n If in-office culturing is done, the manufacturer's instructions must be followed very carefully to avoid errors. n The culturing of the spore test is usually handled through the use of a mail-in monitoring service. n The culture can also be done in the dental office. n If in-office culturing is done, the manufacturer's instructions must be followed very carefully to avoid errors. Biologic Indicators  cont’d

37. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-14 The use of a mail-in service is a convenient method of biologic monitoring. (Courtesy SPSMedical.) Fig. 21-14

38. Copyright 2003, Elsevier Science (USA). All rights reserved. Types of Biologic Indicators n One type of bacterial spore is used to test the steam autoclave and chemical vapor sterilizer. n Different bacterial spores are used to test the dry heat and ethylene oxide sterilizer. n Dual species biologic indicators that contain spores of both organisms are available and can be used with dry heat, ethylene oxide, autoclave, or chemical vapor. n One type of bacterial spore is used to test the steam autoclave and chemical vapor sterilizer. n Different bacterial spores are used to test the dry heat and ethylene oxide sterilizer. n Dual species biologic indicators that contain spores of both organisms are available and can be used with dry heat, ethylene oxide, autoclave, or chemical vapor.

39. Copyright 2003, Elsevier Science (USA). All rights reserved. Sterilization Failure n Several things can cause the sterilization process to fail, including improper instrument cleaning and packaging, as well as malfunction of the sterilizer. n A load may fail to become sterilized when there is not direct contact for the proper length of time between the sterilizing agent and the items to be sterilized. n Several things can cause the sterilization process to fail, including improper instrument cleaning and packaging, as well as malfunction of the sterilizer. n A load may fail to become sterilized when there is not direct contact for the proper length of time between the sterilizing agent and the items to be sterilized.

40. Copyright 2003, Elsevier Science (USA). All rights reserved. Table 21-4 Causes of Sterilization Failure. Table 21-4

41. Copyright 2003, Elsevier Science (USA). All rights reserved. Sterilization Reports n The monitoring service will generally report a sterilization failure to the dental office immediately by telephone. n If the culture is negative, the monitoring service will mail a report to the dental office. A negative report indicates sterilization did occur. n All reports must be kept on file as part of the documentation requirements of the exposure control program. n The monitoring service will generally report a sterilization failure to the dental office immediately by telephone. n If the culture is negative, the monitoring service will mail a report to the dental office. A negative report indicates sterilization did occur. n All reports must be kept on file as part of the documentation requirements of the exposure control program.

42. Copyright 2003, Elsevier Science (USA). All rights reserved. Sterilization n Sterilization destroys all microbial forms, including bacterial spores. n Sterile is an absolute term. There is no such thing as “partially sterile” or “almost sterile.” n All reusable items that come in contact with the patient’s blood, saliva, or mucous membranes must be heat-sterilized. n It is not recommended to use a liquid sterilant on any item that can withstand heat sterilization or is disposable. n Sterilization destroys all microbial forms, including bacterial spores. n Sterile is an absolute term. There is no such thing as “partially sterile” or “almost sterile.” n All reusable items that come in contact with the patient’s blood, saliva, or mucous membranes must be heat-sterilized. n It is not recommended to use a liquid sterilant on any item that can withstand heat sterilization or is disposable.

43. Copyright 2003, Elsevier Science (USA). All rights reserved. Methods of Sterilization n The three most commonly used forms of heat sterilization in the dental office are: Steam sterilization Chemical vapor sterilization Dry heat sterilization n The three most commonly used forms of heat sterilization in the dental office are: Steam sterilization Chemical vapor sterilization Dry heat sterilization

44. Copyright 2003, Elsevier Science (USA). All rights reserved. Steam Autoclave Sterilization n Steam sterilization involves heating water to generate steam, producing a moist heat that rapidly kills microorganisms. n Manufacturers set their sterilizers (autoclaves) to reach maximum steam temperatures of approximately 250˚ F (121˚ C) with pressures of 15 or 30 pounds per square inch. n A disadvantage of steam sterilization is that the moisture may cause corrosion on some high-carbon steel instruments. n Distilled water should be used in autoclaves instead of tap water, which often contains minerals and impurities. Distilled water can minimize corrosion and pitting. n Steam sterilization involves heating water to generate steam, producing a moist heat that rapidly kills microorganisms. n Manufacturers set their sterilizers (autoclaves) to reach maximum steam temperatures of approximately 250˚ F (121˚ C) with pressures of 15 or 30 pounds per square inch. n A disadvantage of steam sterilization is that the moisture may cause corrosion on some high-carbon steel instruments. n Distilled water should be used in autoclaves instead of tap water, which often contains minerals and impurities. Distilled water can minimize corrosion and pitting.

45. Copyright 2003, Elsevier Science (USA). All rights reserved. Fig. 21-15 A steam autoclave. Fig. 31-15

46. Copyright 2003, Elsevier Science (USA). All rights reserved. Types of Steam Sterilizers n All steam sterilizers operate in a similar manner, but different models and brands have different features. n There are various sizes of chambers and mechanisms of air removal, steam generation, drying, temperature displays, and recording devices. n Rapid or “flash” sterilization of dental instruments is accomplished by rapid heat transfer, steam, and unsaturated chemical vapor. n All steam sterilizers operate in a similar manner, but different models and brands have different features. n There are various sizes of chambers and mechanisms of air removal, steam generation, drying, temperature displays, and recording devices. n Rapid or “flash” sterilization of dental instruments is accomplished by rapid heat transfer, steam, and unsaturated chemical vapor.

47. Copyright 2003, Elsevier Science (USA). All rights reserved. Chemical Vapor Sterilization n Very similar to autoclaving, except a combination of chemicals (alcohol, formaldehyde, ketone, acetone, and water) is used instead of water to create a vapor for sterilizing. n OSHA requires a material safety data sheet (MSDS) on the chemical vapor solution because of the toxicity of the chemicals it contains. n The major advantage of the chemical vapor sterilizer is that it does not rust, dull, or corrode dry metal instruments. n A wide range of items can be sterilized routinely without damage. Other advantages are the short cycle time and having a dry instrument at the end of the cycle. n Very similar to autoclaving, except a combination of chemicals (alcohol, formaldehyde, ketone, acetone, and water) is used instead of water to create a vapor for sterilizing. n OSHA requires a material safety data sheet (MSDS) on the chemical vapor solution because of the toxicity of the chemicals it contains. n The major advantage of the chemical vapor sterilizer is that it does not rust, dull, or corrode dry metal instruments. n A wide range of items can be sterilized routinely without damage. Other advantages are the short cycle time and having a dry instrument at the end of the cycle.

48. Copyright 2003, Elsevier Science (USA). All rights reserved. Monitoring Chemical Vapors n The primary disadvantage is that adequate ventilation is essential because residual chemical vapors containing formaldehyde and methyl alcohol can be released when the chamber door is opened at the end of the cycle. n These vapors can temporarily leave an unpleasant odor in the area and may be irritating to the eyes. n Newer models are equipped with a special filtration device that further reduces the amount of chemical vapor remaining in the chamber at the end of the cycle. n Formaldehyde monitor badges that are worn by the employee (much like radiation monitoring devices) are available. n The primary disadvantage is that adequate ventilation is essential because residual chemical vapors containing formaldehyde and methyl alcohol can be released when the chamber door is opened at the end of the cycle. n These vapors can temporarily leave an unpleasant odor in the area and may be irritating to the eyes. n Newer models are equipped with a special filtration device that further reduces the amount of chemical vapor remaining in the chamber at the end of the cycle. n Formaldehyde monitor badges that are worn by the employee (much like radiation monitoring devices) are available.

49. Copyright 2003, Elsevier Science (USA). All rights reserved. Packaging for Chemical Vapor Sterilization n Types of wraps include film pouches or paper bags, nylon see-through tubing, sterilization wraps, and wrapped cassettes. n Thick or tightly wrapped items require longer exposure. n Closed containers, such as solid metal trays, capped glass vials, and aluminum foil, cannot be used in a chemical vapor sterilizer because they prevent the sterilizing agent from reaching the instruments inside. n Types of wraps include film pouches or paper bags, nylon see-through tubing, sterilization wraps, and wrapped cassettes. n Thick or tightly wrapped items require longer exposure. n Closed containers, such as solid metal trays, capped glass vials, and aluminum foil, cannot be used in a chemical vapor sterilizer because they prevent the sterilizing agent from reaching the instruments inside.

50. Copyright 2003, Elsevier Science (USA). All rights reserved. Pressure, Temperature, and Time n The three major factors in chemical vapor sterilization are: Pressure (20 psi) Temperature 131˚ C (270˚ F) Time (20 to 40 minutes) n The three major factors in chemical vapor sterilization are: Pressure (20 psi) Temperature 131˚ C (270˚ F) Time (20 to 40 minutes)

51. Copyright 2003, Elsevier Science (USA). All rights reserved. Handpiece Sterilization n High-speed dental handpieces rotate at speeds up to 400,000 rpm. n Blood, saliva, and tooth fragments, as well as restorative materials, may get into the head of the handpiece, where they may be retained and transferred to another patient. n Therefore, dental handpieces must be properly cleaned and heat-sterilized. n High-speed dental handpieces rotate at speeds up to 400,000 rpm. n Blood, saliva, and tooth fragments, as well as restorative materials, may get into the head of the handpiece, where they may be retained and transferred to another patient. n Therefore, dental handpieces must be properly cleaned and heat-sterilized.

52. Copyright 2003, Elsevier Science (USA). All rights reserved. Flushing of Handpieces n If debris is not removed before heat sterilization, it will bake onto the turbine and bearings. n Flushing the handpiece is the best way to remove debris from the head of the handpiece. n Attach a pressurized handpiece cleaner to the intake tube of the handpiece (where the air passes through) and flush the head of the handpiece to remove debris. n Afterward, blow out the handpiece using compressed air to remove debris before sterilization. n Coolant water does not run through the turbine chamber, where debris can collect and compromise handpiece life. n If debris is not removed before heat sterilization, it will bake onto the turbine and bearings. n Flushing the handpiece is the best way to remove debris from the head of the handpiece. n Attach a pressurized handpiece cleaner to the intake tube of the handpiece (where the air passes through) and flush the head of the handpiece to remove debris. n Afterward, blow out the handpiece using compressed air to remove debris before sterilization. n Coolant water does not run through the turbine chamber, where debris can collect and compromise handpiece life.

53. Copyright 2003, Elsevier Science (USA). All rights reserved. Sterilizing Handpieces n Only steam sterilization and chemical vapor sterilizers are recommended, because handpiece sterilization temperatures should not exceed 275˚ F (135˚ C). n Never run a handpiece hot out of the sterilizer, and avoid rapid cool-downs, such as running the handpiece under cold water. n Handpieces use very small metal components; taking them from very hot to very cold temperatures stresses the metal. Instead, if handpieces need to be cooled quickly after sterilization, use an air fan to blow room-temperature air over it. n Only steam sterilization and chemical vapor sterilizers are recommended, because handpiece sterilization temperatures should not exceed 275˚ F (135˚ C). n Never run a handpiece hot out of the sterilizer, and avoid rapid cool-downs, such as running the handpiece under cold water. n Handpieces use very small metal components; taking them from very hot to very cold temperatures stresses the metal. Instead, if handpieces need to be cooled quickly after sterilization, use an air fan to blow room-temperature air over it.