Infection Control in Dentistry

• The purpose of this presentation is to provide relevant information on the principles of infection prevention and control in dentistry.
• By the end of this session, students should be able to:
• Explain the importance of infection prevention and control to the patient, dental team and wider public.
• Identify dangers in the dental surgery
• Differentiate between decontamination, disinfection and sterilisation techniques.
• Possess knowledge of PPE and its correct usage
• Describe clinician responsibilities in preventing cross infection, the need for up-to-date immunisation, and why proper cleaning is essential.
• Understand the zoning technique to ensure environmental infection control.
• Explain inoculation injuries and their avoidance in the dental workplace.
• Recognise the need for proper waste disposal.
• Relevant GDC Learning Outcomes include:
• Explain the potential routes of transmission of infectious agents in dental practice, mechanisms for the prevention of infection, the scientific principles of decontamination and disinfection and their relevance to health and safety (1.1.7).
• Implement and perform effective decontamination and infection control procedures according to current guidelines (1.8.2).
• Infection control is the methods and measures employed in a workplace (in this case, a dental workplace).
• The aim of infection control is to prevent contamination of everyone, acquiring an infection from a patient or another staff member, or from a dirty instrument.

Statistics

• 7 in 100 patients will acquire at least one health-care related infection in developed countries, compared to 10 in 100 patients in developing countries.
• Sharps injuries cause an estimated 66,000 HBV, 16,000 HCV, and 200-500 HIV infections among health-care workers each year.
• This equates to 37%, 39% and 4.4% of health-care workers worldwide, respectively (WHO 2003).
• There were an estimated 834,000 HCAls in 2016/2017 costing the NHS £2.7 billion, and accounting for 28,500 patient deaths (BMJ 2019).
• Those at risk of infection are:
• Dentist
• Hygienist/Therapist
• Dental Nurse
• Technician
• Patient
• Also Families/Commuters

Importance of Infection Control

• All members of the dental team have a duty of care to protect their patients, colleagues and themselves in a dental workplace (DH 2013).
• It is important to prevent contamination or acquiring. an infection from a patient, staff member or a dirty instrument.
• Regulation in England for health care providers is overseen by the CQC.
• Compliance with the HTM 01-05 (2013) ensures each workplace meets registration requirements of the CQC.
• Compliance with the GDC Standards is required.
• The mouth is full of microorganisms, instruments used in dentistry become contaminated, and without cleaning, cross-infection would occur.
• The Goal is to break the Cycle of Infection by disrupting:
• Pathogen
• Infection control/hygiene
• Transmission mode
• Individual treatment
• Colonisation and/or infection
• Immunisation or chemoprophylaxis
• Susceptible person

Dangers in Dental Surgery

• Pathogenic microorganisms of concern to the dental team include:
• Herpes Simplex type I
• Hepatitis B
• Hepatitis C
• New-variant Creutzfeldt-Jakob disease (vCJD)
• Human immunodeficiency virus (HIV)
• COVID-19 & any AGPs
• All dental staff must receive the following immunisations before working at the chair side:
• Poliomyelitis
• Tuberculosis
• Tetanus
• MMR (measles, mumps & rubella)
• Diphtheria
• Pertussis (whooping cough)
• Hepatitis B

PPE

• Personal Protective Equipment (PPE):
• Is worn to protect staff from coming into contact with blood and other bodily fluids.
• Is a legal requirement for dental employers to provide PPE for their staff.
• Should be worn correctly as stipulated in the Infection Control policy.
• Uniforms:
• UCLH Dress code and Uniform policy requires all patient-facing staff (including dental) to wear a uniform.
• This is for infection control and health & safety purposes.
• Footwear:
• Must be safe and sensible, with a flat/low heel and in good order.
• Should cover all toes with good soles & heels and not make unnecessary noise in a clinical area.
• Nails, Hair, Jewellery, Piercings:
• Nail varnish, nail extensions and false nails are not permitted, nails should be short.
• Long hair must be tied back and up and should not fall below the shoulders.
• Long fringes must be clipped back or held with a band to avoid hand-hair contact.
• Only one small earring per ear is allowed.
• No necklaces are allowed.
• Body piercings must be covered with a plaster during work.
• For cultural reasons only, a small, discreet nose stud is allowed.
• Plastic aprons are single-use.
• They should be worn on top of the uniform during procedures when soiling may occur or while cleaning the clinical area.
• Gloves are variable in quality.
• Gloves can be latex or non-latex and should be changed between patients if torn or heavily soiled.
• Hands frequently become Contaminated during glove removal, and gloves are not a substitute for hand washing.
• Face masks
• For AGP procedures, a mask you have been fit-tested with must be worn when treating a patient known or suspected to be suffering from an infectious agent transmitted partly or wholly via airborne or droplet route.
• Eye protection
• Visors or face shields should be worn.
• Eye protection should be cleaned between patients with disinfectant wipes.
• Loupes are a substitute for protective eyewear, but masks must be worn with loupes.

Hand Hygiene

• Comprises of hand washing and disinfection using anti-bacterial rubs/gels
• Is important in preventing the spread of infection and the recontamination of sterile instruments and devices.
• Clean hands are an essential counterpart to the use of gloves, with hand hygiene/hand-washing technique taking 40-60 seconds as specified by the WHO
• Hand hygiene is important at these times:
• Before and after each treatment session
• Before and after removing PPE
• After washing dental instruments
• Before contact with sterilised instruments
• After the completion of decontamination work
• After cleaning or maintaining decontamination devices used on dental instruments
• Sinks are dedicated for hand-washing and operated by elbow or foot to avoid recontamination; liquid soap is needed.
• Alcohol-based hand rub benefits limitations
• Benefits are that it provides rapid and effective antimicrobial action, reduces time for hand disinfection and is more accessible than sinks.
• Limitations are that it cannot be used if hands are visibly soiled, instructions should be followed, it is highly flammable so safety precautions should be implemented and it cannot be used repeatedly.
• Skin care advice
• Use approved hand creams & lotions
• Check compatibility with the manufacturer
• Some lotions can render medicated soap less effective
• Some lotions cause a breakdown of latex gloves (e.g. petroleum based)
• Lotions can become contaminated with bacteria if dispensers are refilled.

Cleaning

• Social cleaning - clean to a socially acceptable standard, but not disinfected nor sterilised
• Disinfection - the killing/destruction of bacteria & fungi, but not spores nor some viruses (technique usually involves use of chemicals).
• Sterilisation - the process of killing all microorganisms to produce asepsis; autoclaves are used.
• Asepsis - the absence of all living pathogenic microorganisms.
• The entire dental area should be cleaned to a socially acceptable standard (often by a domestic cleaner).
• The cleaning standard to be achieved is disinfection.
• Clinical areas should be designated clean and dirty so used instruments are not placed where clean items should be.
• This is called ZONING
• Clinical contact surfaces:surfaces become contaminated from patient materials, either by direct spray or spatter generated during dental procedures or by contact with the dental care professional's gloved hands.
• To clean in between patients: You must wear gloves, Remove sharps first,Ensure all instrument trays are securely closed ,Disinfect the chair & then all surfaces
• Instruments Must meet essential quality requirements and be cleaned regardless of method used
• Three main techniques currently used for cleaning reusable dental equipment: Manual cleaning, Manual cleaning with ultrasonic decontamination and Decontamination & cleaning with washer- disinfector
• For Autoclaving a Moist heat, boiling is INSUFFICIENT .
  • 134°C is the temperature
  • 32lb/sq (Psi) is the pressure
  • cycle time= 3.5min
• Dry heat sterilization
  • A Hot Air oven is used
  • Suitable for instruments with sharp cutting edge
• For instruments and working surfaces chemical disinfection is an option when:
• At a certain temperature & concentrations
• When object must be cleaned
• When agent needs a the right amount of exposure time
• When shelf life is considered as certain chemicals may damage

Waste Disposal

• Mandatory Training
• Clinical waste is waste that is contaminated with blood, saliva, or other bodily fluids and may be hazardous to anyone who touches it
• It is disposed of in the appropriately labelled bins in clinic (tiger striped)
• There are other bins on clinic for non-clinical waste
• NEVER touch clinical waste with ungloved hands
• All needles burs or matrices etc. and sharps cartridges must be placed in a sharps box
• Sharps Container should be disposed of when 2/3 full

Dental Unit Water Line (DUWL) & Biofilm

• Biofilm is a layer of micro-organisms contained in a matrix (slime layer),which forms on substances in contact with water
• World Heath organisation says it should be free from health hazards
• Most contaminants non pathogenic and it is a concern for immunosuppressed individuals
• Concern exists regarding opportunistic respiratory pathogens is over Legionella
• Coming from Mains Bacteria and not likely from orally

Reducing Biofilm

• Management systems must keep level acceptable to the NB. DUWL are medical
• Flush to reduce risk suck-back but to remove it needs to be flushed out daily this helps bacterial
• It can be disinfected Weekly
• Extended periods of use (e.g., bank holidays, Christmas), use Bilpron.