Lecture 16 Strategies In Contaminated Zones (Radiology and Labs) PDF

Strategies Within The Contaminated Zones Radiology Unit & Dental Lab Basic infection control measures Dr. Sanabel Barakat Semester 1 / year 3 BDs., MSc., PhD., JDC. Week 6  ILOs 1. Describe how to properly disinfect microbially soiled...

Strategies Within The Contaminated Zones Radiology Unit & Dental Lab Basic infection control measures Dr. Sanabel Barakat Semester 1 / year 3 BDs., MSc., PhD., JDC. Week 6  ILOs 1. Describe how to properly disinfect microbially soiled prostheses and impressions. 2. Describe an acceptable laboratory receiving area. 3. List how to properly sterilize laboratory items used intraorally and correct disinfection procedures for laboratory items not used intraorally. 4. Design a system of proper environmental barriers and disinfection used during radiographic processes and the aseptic processing of radiographic films 2 LABORATORY ASEPSIS 3  LABORATORY ASEPSIS Any instrument or piece of equipment used in the oral cavity or on orally soiled prosthetic devices or impressions is a potential source of cross-infection. It is impossible to identify all infectious patients from medical histories or patient conversations. Therefore, the only valid posture is to assume (and act as if) all patients are capable of transmitting highly infectious diseases (standard precautions). If contaminated items were to enter the laboratory environment, infectious materials could spread to prostheses and appliances of other patients; and laboratory personnel also could be placed at increased risk for cross-infection. 4 Microbially Soiled Prostheses and Impressions CLINIC LAB 5  Protective Barriers All items coming from the oral cavity must be sterilized or disinfected before being worked on in the laboratory and before being returned to the patients. Asepsis procedures vary for each type of dental material. General recommendations for procedures and materials can be made. 6 Protective Barriers Laboratory infection control also involves, depending on need, the wearing of personal protective equipment (PPE), such as gloves, safety eyewear, gowns, and masks. 7  Protective Barriers A successful laboratory infection control program requires meeting two major criteria: (1) the use of proper methods and materials for handling and decontaminating soiled items (2) the establishment of a coordinated infection control program between dental offices and laboratories. This program will help dental practitioners and dental technologists create and maintain mutually effective infection control protocol. 8 Receiving Areas Create a receiving area to handle all items sent to the laboratory or handled in the laboratory areas within the dental practice. No item (impression or prosthesis) should enter the receiving area until it has been disinfected properly. The area needs running water and handwashing facilities. 9 Receiving Areas To cover the area and the counter surfaces with impervious paper and to clean and disinfect the area regularly is the best practice. The amount of cleaning and disinfection depends on the rate of use of the area. Use PPE when handling items received in the laboratory unit until the items have been disinfected. 10  Microbially Soiled Prostheses and Impressions Any prosthesis coming from the oral cavity is a potential source of infection Most prostheses and appliances cannot withstand standard heat-sterilization procedures. An alternative technique for most prostheses is disinfection by immersion after a thorough cleaning. 11 Microbially Soiled Prostheses and Impressions Clean, disinfect, and rinse all dental prostheses and prosthodontic materials (e.g., impressions, bite registrations, and occlusal rims) using registered disinfectant having at least an intermediate level of activity (tuberculocidal claim) before handling the items in the laboratory. Note manufacturers instructions regarding the stability of specific materials (e.g., impression materials) relative to disinfection procedures. 12 Microbially Soiled Prostheses and Impressions wear gloves and protective outerwear when handling prostheses until they have been disinfected properly. Some heavily soiled (e.g., with calculus or adhesive) prostheses require cleaning or scrubbing before disinfection. The most efficient (and safest) procedure is to place the prostheses into zippered plastic bags containing ultrasonic detergent and then place the assembly into an ultrasonic cleaner 13 Microbially Soiled Prostheses and Impressions One should rinse impressions with tap water after removing from the patient’s mouth, then shake them to remove residual water. One then places rinsed impressions into glass beakers or zippered plastic bags containing an appropriate disinfectant After 15 minutes, one removes the impressions, rinses them well with tap water, and gently shakes them. The impressions are now ready for pouring 14  Microbially Soiled Prostheses and Impressions Some types of impressions are sensitive to immersion. Careful selection of disinfectant is required. As an alternative, spray these impressions thoroughly and wrap them with paper towels moistened well with the same disinfectant solution. The fibers from paper towels may stick to some impression materials. (manufacturer instructions) After 15 minutes, one removes the impressions, rinses them well, and shakes them gently, and they are ready to be poured. 15  Microbially Soiled Prostheses and Impressions Spraying Spraying is the treatment of choice for some types of dental materials, for it uses less solution and often one can use the same disinfectant for general disinfection of environmental surfaces. Spraying is probably not as effective as immersion, because one cannot ensure constant contact of disinfectant with all surfaces of the impression. Spraying also releases disinfectant into the air, thus increasing the chances of personnel exposure. 16  Microbially Soiled Prostheses and Impressions Spraying When given a choice, one always should select immersion. Most disinfectants can be used for spraying. One should clean and heat-sterilize heat-tolerant items used orally, including items, such as metal impression trays and facebow forks. 17 Microbially Soiled Prostheses and Impressions PPE ✓ Wear masks and protective eyewear when handling hazardous chemicals, such as disinfectants. ✓ Eye/face protection is mandatory whenever one uses rotary or air- blasting cleaning equipment. ✓ Onealso can use glass or plastic beakers or containers. ✓ If further hand-scrubbing or cleaning is required, keep personal barriers in place. ✓ Use air-powered blasters, such as shell blasters, only on cleaned and disinfected prostheses. 18 Microbially Soiled Prostheses and Impressions LAB CLINIC 19  Microbially Soiled Prostheses and Impressions The team members must follow the same procedures when they receive prostheses from the dental laboratory. Prostheses that have been disinfected properly (treated and rinsed) can be returned to the patient office in a deodorizing solution, such as a mouth rinse. Because of the increased risk for adverse tissue response (to the patient and the office staff), prostheses should never be sent out or returned in disinfectant solutions. 20  Microbially Soiled Prostheses and Impressions 21  Grinding, Polishing, and Blasting As stated before, perform laboratory work on previously disinfected impressions, appliances, and prostheses. Bringing untreated materials into the laboratory establishes the potential for cross- contamination. 22  Grinding, Polishing, and Blasting The rotary action of the wheels, stones, and bands generates aerosols, spatter, and projectiles. Whenever one is using the lathe, one should wear protective eyewear, properly place the front Plexiglas shield, and ensure that the ventilation system is operating properly. The use of a mask is highly recommended. The air-suction motor should be capable of producing an air velocity of at least 200 ft/min. Maximum containment of aerosols and spatter can be achieved when a metal enclosure with hand holes is fixed to the front of the hood of the lathe. 23  Grinding, Polishing, and Blasting One can sterilize or disinfect all attachments, such as stones, rag wheels, and bands, between uses or throw them away. The lathe unit must be disinfected twice a day. One should use fresh pumice and pan liners for each case 24  Grinding, Polishing, and Blasting Polishing of appliances and prostheses before delivery is a necessary activity. Polishing exposes the operator to potential crosscontamination and physical injury (PPE). However, if the item being polished has been prepared aseptically, the risks of infection are reduced to a minimum. To avoid the potential spread of microorganisms, one should obtain all polishing agents (e.g., rouge) in small quantities from larger reservoirs. One should never return unused material to the central stock but should throw it away. Most polishing attachments (e.g., brushes, wheels, and cups) are single-use disposable items. sterilize reusable items between uses, if possible, or at least disinfect the items. Remember, protect against respiratory and eye contact with airborne particles when using gypsum, alginate, pumice, rouge, and microblasting materials (PPE). 25  Intermediate Cases Complete and partial dentures often undergo an intermediate wax try- in stage. Crowns, splinted bridges, and partial denture frameworks often are “test seated” before cementation or soldering. These devices, like wax try-in step dentures, can become soiled with oral fluids. Before returning the items to the laboratory for further processing, one must disinfect them. The procedures in most cases are the same as those described for completed projects. 26 Microbially Soiled Prostheses and Impressions LAB CLINIC 27  Microbially Soiled Prostheses and Impressions The team members must follow the same procedures when they receive prostheses from the dental laboratory. Prostheses that have been disinfected properly (treated and rinsed) can be returned to the patient office in a deodorizing solution, such as a mouth rinse. Because of the increased risk for adverse tissue response (to the patient and the office staff), prostheses should never be sent out or returned in disinfectant solutions. 28  Return of Completed Cases Appliances and prostheses that are returned to the patient are not free of microbial contamination. These organisms could come from other cases and from the operator’s body if aseptic procedures are not followed rigorously. Many patients have open oral lesions or are traumatized sufficiently during treatment so as to facilitate easier microbial penetration. A number of patients also have impaired immune defense systems or are on chemotherapy programs that render them more susceptible to infectious diseases. The best location for disinfection procedures is chairside. 29  LABORATORY ASEPSIS 1. Gloves, mask, protective eyewear, and protective clothing are used until items received in the laboratory are decontaminated. 2. Before items are handled in the laboratory, all dental prostheses and prosthodontic materials (e.g., impressions, bite registrations, occlusal rims, extracted teeth) are cleaned, disinfected, and rinsed using a hospital disinfectant registered by the EPA and having at least an intermediate level (i.e., tuberculocidal claim) activity. 3. Manufacturers are consulted regarding the stability of specific materials (e.g., impression materials) relative to disinfection procedures. 4. Specific information regarding disinfection technique used (e.g., solution used and duration) is included when laboratory cases are sent off-site and upon their return. 31  LABORATORY ASEPSIS 5. Heat-tolerant items used in the mouth (e.g., metal impression trays, face-bow forks) are cleaned and heat-sterilized. 6. The manufacturer’s instructions are followed for cleaning and sterilizing or disinfecting items that become contaminated but that do not normally contact the patient (e.g., burs, polishing points, rag wheels, articulators, case pans, lathes). Some of these items are disposable. If manufacturer instructions are not available, heat-tolerant items are cleaned and heat-sterilized or cleaned and disinfected with an EPAregistered hospital disinfectant with low- (HIV, HBV effectiveness claim) to intermediate-level (tuberculocidal claim) activity, depending on the degree of contamination. 32  RADIOGRAPHIC ASEPSIS 33  RADIOGRAPHIC ASEPSIS Consistent use of the most effective and efficient types of PPE—such as gloves, masks, gowns, and eyeglasses—decreases the chances of exposure to infectious agents. The team also must use appropriate environmental covers and perform cleaning and disinfection. 34  RADIOGRAPHIC ASEPSIS For dental radiology, only a limited number of items require sterilization. Use heat tolerant or disposable intraoral devices whenever possible (e.g., film-holding and positioning devices) and should clean and heat-sterilize heat-tolerant devices between patients. 35  Taking of Radiographs Use films held within FDA-cleared barrier pouches Place exposed films into a disposable plastic cup or onto a labeled paper towel. This procedure helps to minimize contamination and also facilitates transport. Because of time constraints, many offices elect to cover the majority of the involved surfaces, such as x- ray cones, rather than routinely clean and disinfect them. 39  Digital Radiographic Sensors Digital radiographic sensors and associated computer hardware can be used in place of x-ray films. The digital system allows the image to be displayed on a computer monitor at chairside. The image can then be manipulated and stored for future retrieval. Unlike x-ray films, digital sensors are used repeatedly on multiple patients. 40  Digital Radiographic Sensors Digital sensors cannot be heat-sterilized or chemically disinfected. In these cases, the only alternative is to prevent the sensor from becoming contaminated. This is accomplished by using a disposable plastic surface barrier over the sensor and part of the attached wire (unless the sensor is wireless) 41  RADIOGRAPHIC ASEPSIS Unit, Film, and Patient Preparation The radiographic process offers the possibility that body fluids will contaminate disposable and reusable items. One must wear gloves of when taking radiographs and when handling orally soiled radiographic films. Because taking radiographs is a clinical activity, one must also consider the protective gowns and masks worn for restorative procedures. Protective eyewear is a barrier against contact with patient fluids but also prevents exposure to hazardous chemicals. 45  RADIOGRAPHIC ASEPSIS Unit/Patient Preparation 1. Before seating the patient, the unit is prepared by covering or cleaning and disinfecting all surfaces that will be touched or exposed to potentially infectious materials. 2. The medical history of the patient is reviewed or updated. 3. After hand hygiene, gowning, and gloving, the appropriate number and type of films to be taken are determined. 4. The films in disposable barriers pouches are obtained from a central distribution area or film dispenser while wearing clean gloves or the digital x-ray sensor is covered with the appropriate barrier. 5. After degloving, the films or sensor are exposed in the recommended manner. 46  RADIOGRAPHIC ASEPSIS Unit/Patient Preparation 6. Exposed films are placed on a paper towel or in a cup. If film packs are pre-covered with plastic protectors, the contaminated barriers are carefully removed after exposure, and the film packs are dropped onto a clean surface. The film packs are not touched with contaminated gloves. 7. Surface barriers are removed from the unit, or contaminated surfaces are cleaned and disinfected. 8. Gloves are removed, and hands washed or an alcohol-based hand rub is used. 47  Darkroom Processing 1. Fresh gloves are donned. 2. The films are carried to the darkroom using caution not to touch doors, walls, work areas, or processors with contaminated gloves. 3. With gloved hands, the film packets are carefully opened, and the films are dropped onto a clean paper towel. The contaminated film wrappers are placed into the designated refuse containers. 48  Darkroom Processing 4. Contaminated gloves are removed, the films are placed in the processor, and hand hygiene is performed. 5. After processing, the films are placed into the appropriate mounts using care not to contaminate the films, mounts, or charts with instruments that were used in the operatory. 49  Daylight Loader Processing Because of the limited operating space inside the loader and because the hand insertion sleeves cannot be disinfected, only films that are not contaminated are placed in the loader. 50  Daylight Loader Processing This is accomplished in two ways: a. Film packet disinfection: (Only plastic film packets may be disinfected). After the films have been exposed, they are rinsed with water, soaked in an appropriate bleach or iodophor solution for 10 minutes, and while wearing clean gloves, rinsed with water and dried with a clean paper towel. The films are placed into the loader through the top. 51 Daylight Loader Processing b. Preexposure wrapping: Film packs already protected with a removable plastic barrier are available. After exposure, the outer wrapping is carefully opened, and the film packet is dropped onto a clean surface. Caution is used so that the clean packets do not touch the contaminated gloves or wrapping. The films are placed in the loader through the top, and after donning new gloves, the hands are passed through the insertion sleeves. Do not contaminate the insertion sleeves. 52 53