Case Studies in Infection
Training in Infection Control
The Bug Blog
Page updated 9 October 2006
Disinfection is a process used to reduce the number of viable microorganisms but may not inactivate certain viruses and bacterial spores. Disinfection should be limited to equipment, which cannot be reprocessed using other methods and is strongly discouraged in dental practice as a form of sterilisation, as most equipment can be steam sterilized or is available as single use disposable items.
When selecting a disinfectant for heat sensitive equipment, check that it is active against bacterial spores, M. tuberculosis and viruses including HIV, HCV and HBV. The disinfectant must be compatible with the instrument or equipment and not corrode, damage or have a deleterious effect on its function. Always check first with the manufacturer before using a new disinfectant. Finally, read the disinfectant's Safety Data Sheet, as some disinfectants require special conditions for use such as exhaust ventilation in order to prevent adverse reactions occurring e.g. skin hypersensitivity or asthma. An example is Glutaraldehyde which is NOT suitable for general dental practice as it is an irritant and sensitises the skin, eyes and respiratory tract.
You will need to prepare a written COSHH assessment on all disinfectants used in the practice.
|Airways and endotracheal tubes||
Single use items. Any re-usable items should be steam sterilized.
|Bracket table and handle||
Cover with cling film during use; then disinfect with surface disinfectant e.g. alcohol wipe
|Brushes (for cleaning equipment)||
Discard, or clean and autoclave following use. Store dry.
|Burs (diamond, tungsten carbide)||
Immerse in enzymic (e.g. Alkazyme) disinfectant, follow manufacturer's instructions on dilution and immersion time. Steam sterilize and dry.
Steel burs are a single use item.
Not suitable for clinical areas.
Vacuum regularly (normally daily). Steam clean periodically.
Cover tip with cling film or impervious plastic sleeve. (Tips also available as sterilizerable or as single use disposable). Wipe outer casing with surface disinfectant or alcohol wipe after use on each patient.
Glass: clean and steam sterilizer; Plastic: single use disposable
|Dental Chair and stools||
Covering should be intact. Clean regularly with warm water and detergent. Blood/body fluid splashes should be cleaned immediately with dilute hypochlorite solution and wiped with a manufacturer recommended surface disinfectant.
|Dental chair switches||
Cover with cling film, change between patients, end of session disinfect with surface disinfectant
|Dental Handpieces and connectors||
Automatic cleaning device recommended or cleaning and pre-oiling according to handpiece manufacturer's instructions prior to placement in vacuum (or if not available a non-vacuum) sterilizer. Handpiece couplings and hose cover with impervious sleeve/cling film; clean with surface disinfectant
|Endodontic RCT instruments||
Files and reamers most are single use only, but if designated re-usable by manufacturer e.g. some rotary files, then brush clean and place in ultrasonic bath, steam sterilize. Bent or damaged instrument should be discarded.
Remove debris and clean, use surface disinfectant, steam sterilize the fork.
|Fan (mechanical) and Air Conditioning||
Avoid use of fans in clinical areas as difficult to clean effectively. If use is considered essential, then routinely wipe clean with detergent. Regularly change filters and clean air conditioning units.
|Furniture and fittings||
Should be in good repair and all coverings intact. Damp dust with warm water and detergent. If known contamination, wash with diluted hypochlorite solution. Choose furniture upholstered with wipeable fabrics.
Manual cleaning and ultrasonic bath or thermal washer disinfector; Steam sterilize; store in clean dry container /tray. Preferably sterilized in pouches in a vacuum autoclave.
Manual cleaning or thermal washer disinfector, steam sterilize; or use disposables
Cover with cling film and replace between patents. Clean with surface disinfectant at end of session
Single use item.
Single use item
Clean and sterilize.
Single use only (generally not recommended for hand hygiene in
Single use item. Resheath carefully with finger guard protectors or other resheathing device or if not available single handed scoup method. Dispose of plastic syringes and needles as one unit into sharps bin. Consider using retractable safety needles.
Use pre-sterilized packs
Handle with gloves, use barrier pouch
|Radiographic film holders and positioning devices||
Sterilize, if not heat tolerant then clean by immersion in disinfectant
|Radiograph tube- heads and control panels||
Protect with cling film (impervious barrier) change after each patient
Use 70% isopropyl alcohol wipes on bell and earpieces.
|Suction equipment and Spittoon||
Disposable suction tips. Clean using warm water and non-foaming disinfectant. Filters changed according to manufacturer's instructions. Tubing and lines disinfected according to chair and spittoon instructions
High-level disinfection according to manufacturer's instructions or use disposable strips. DO NOT AUTOCLAVE
|Ultrasonic scalers and handle||
Scalers are steam sterilized, cover handles in cling film or impervious plastic sleeves that are changed after each use and wipe connector and hose with surface disinfectant.
Dental impressions become contaminated with saliva, blood and oral bacteria . Less commonly they may become contaminated with respiratory pathogens, which are coughed up into the mouth from the lungs. For example, impressions taken on a patient previously diagnosed with tuberculosis were found to harbour the causative agent Mycobacterium tuberculosis .
Metal impression trays are reusable and should be thoroughly cleaned, immersed in an ultrasonic bath or processed in a thermal washer disinfector and then steam sterilized.
Equipment, which has been contaminated with blood/body fluids, or has been exposed to patients with a known infectious disease, must be decontaminated before being sent to third parties for inspection, service or repair (see DB 2003 (05) June 2003). The device or equipment should not expose the recipient to biological, chemical or radiation hazards. Specific advice on decontamination procedures should be obtained from the manufacturer. All equipment to be inspected, serviced or repaired must be assessed and a declaration of contamination status form completed. Sample forms and further guidance can be obtained from the MHRA website. The contamination status form should state whether the item:
If equipment cannot be decontaminated (for example if device needs to be dismantled by an engineer), the repair organisation should be contacted and asked if they will accept an item that has not been decontaminated. If accepted, then it should be labelled with its contamination status and packed and dispatched for service/repair. Please note that it is illegal to send contaminated items through the post. If the repair organisation will not agree to the dispatch of the device, then quarantine the item, label with its contamination status and arrange a site visit to the practice by the service/ repair organization