<img src='The University of Western Australia logo and text on a light blue background with various pills and capsules, mostly in shades of white, pink, red, and blue.'> </img> # DENT 3005:Introduction to Pharmacology ## **Infection control in dental practice** Dr Thuy Linh Truong thuy.truong@uwa.edu.au # **DENT 3005: Introduction to Pharmacology** ## **Infection control in dental practice** Dr Thuy Linh Truong thuy.truong@uwa.edu.au <img alt="The University of Western Australia crest and an Aboriginal art piece with a text box next to it."> </img> # **Acknowledgement** of country The University of Western Australia acknowledges that its campus is situated on Noongar land, and that Noongar people remain the spiritual and cultural custodians of their land, and continue to practise their values, languages, beliefs and knowledge. Artist: Dr Richard Barry Walley OAM **THE UNIVERSITY OF** **WESTERN** **AUSTRALIA** # **Acknowledgement of country** The University of Western Australia acknowledges that its campus is situated on Noongar land, and that Noongar people remain the spiritual and cultural custodians of their land, and continue to practise their values, languages, beliefs and knowledge. Artist: Dr Richard Barry Walley OAM **THE UNIVERSITY OF** **WESTERN** **AUSTRALIA** **Learning Outcomes** **Learning objectives** 1) Explain pathogenicity and virulence of oral microorganisms 2) Identify sources and routes of infection transmission in dentistry 3) Broadly understand the key microbial virulence factors and their effects 4) Discuss the role of vaccines in preventing communicable diseases 5) Apply infection control principles in dental practice 6) Understand the role of pharmacological agents appropriately to manage oral infections A cartoon-style illustration shows a person dressed in a white lab coat holding a bottle of hand sanitizer (labeled "消毒", which means "disinfection" or "sterilization") and applying it to a cartoon microbe which looks scared. # **Learning Objectives** 1) Explain pathogenicity and virulence of oral microorganisms 2) Identify sources and routes of infection transmission in dentistry 3) Broadly understand the key microbial virulence factors and their effects 4) Discuss the role of vaccines in preventing communicable diseases 5) Apply infection control principles in dental practice 6) Understand the role of pharmacological agents appropriately to manage oral infections Pathogenicity and Virulence of Microorganisms - **Pathogenicity** refers to a microorganism's ability to cause disease - **Virulence** refers to the degree or severity of the disease a pathogen can cause ### Key virulence factors | Virulence Factor | Function | Example | |---|---|---| | Adhesins | Enable bacteria to attach to host tissues | Streptococcus mutans in dental plaque | | Invasins | Allow penetration into tissues | Listeria monocytogenes | | Toxins | Damage or kill host cells | Clostridium tetani, E. coli | | Enzymes | Degrade tissue, aid spread | Collagenase, hyaluronidase | | Immune Evasion | Avoid detection or destruction | Capsule in Streptococcus pneumoniae | # **Pathogenicity and Virulence of Microorganisms** - **Pathogenicity** refers to a microorganism's ability to cause disease - **Virulence** refers to the degree or severity of the disease a pathogen can cause ## **Key virulence factors** | Virulence Factor | Function | Example | | :--- | :--- | :--- | | Adhesins | Enable bacteria to attach to host tissues | Streptococcus mutans in dental plaque | | Invasins | Allow penetration into tissues | Listeria monocytogenes | | Toxins | Damage or kill host cells | Clostridium tetani, E. coli | | Enzymes | Degrade tissue, aid spread | Collagenase, hyaluronidase | | Immune Evasion | Avoid detection or destruction | Capsule in Streptococcus pneumoniae | Sources of Infection and Routes of Transmission * Sources of infection * Patients: carriers of bacteria, viruses (e.g., HBV, HCV, HIV) * **Dental instruments and surfaces**: if improperly sterilized * **Aerosols and droplets**: generated during dental procedures * **Routes of transmission** * **Direct contact**: with blood, saliva, or mucosa * **Indirect contact**: via contaminated instruments, gloves, or surfaces * **Droplet transmission**: coughing, sneezing, ultrasonic scalers * **Airborne**: fine aerosols staying suspended and inhaled * **Sharps injuries**: needle-stick or instrument-related injuries # **Sources of Infection and Routes of Transmission** ## **Sources of infection** - Patients: carriers of bacteria, viruses (e.g., HBV, HCV, HIV) - **Dental instruments and surfaces**: if improperly sterilized - **Aerosols and droplets**: generated during dental procedures ## **Routes of transmission** - **Direct contact**: with blood, saliva, or mucosa - **Indirect contact**: via contaminated instruments, gloves, or surfaces - **Droplet transmission**: coughing, sneezing, ultrasonic scalers - **Airborne**: fine aerosols staying suspended and inhaled - **Sharps injuries**: needle-stick or instrument-related injuries Infection control in dental practices * Personal Protective Equipment (PPE) * Hand hygiene * Sterilization of instruments * Surface disinfection * Proper waste disposal * Vaccination of staff A diagram showing a list of infection control measures in a dental practice with corresponding illustrative icons. The measures include PPE, hand hygiene, sterilization of instruments, surface disinfection, proper waste disposal, and staff vaccination. The icons illustrate various scenarios like testing, temperature checks, masks, hand sanitizer, virus control, sample collection, contact tracing, handwashing, vaccination, online consultations, social distancing, take-out, gargling, spray cleaning, thermometers, ventilation, avoiding crowds, managing infectious people, and a doctor giving advice. # **Infection control in dental practices** - Personal Protective Equipment (PPE) - Hand hygiene - Sterilization of instruments - Surface disinfection - Proper waste disposal - Vaccination of staff **Role of vaccines in preventing infectious diseases** * **Vaccines stimulate the immune system to develop memory against specific pathogens without causing disease** * **Important vaccines for dental professionals** * Hepatitis B (mandatory for dental workers) * Influenza (annual) * COVID-19 * Tetanus, Diphtheria, Pertussis * Measles, Mumps, Rubella (MMR) * **Mechanism of action**: vaccines introduce antigens that mimic the pathogen, leading to an immune response. This results in antibody production and immune memory # **Role of vaccines in preventing infectious diseases** - **Vaccines stimulate the immune system to develop memory against specific pathogens without causing disease** ## **Important vaccines for dental professionals** - Hepatitis B (mandatory for dental workers) - Influenza (annual) - COVID-19 - Tetanus, Diphtheria, Pertussis - Measles, Mumps, Rubella (MMR) ## **Mechanism of action** - Vaccines introduce antigens that mimic the pathogen, leading to an immune response. This results in antibody production and immune memory. **Pharmacological considerations in infectious disease management** * **Antibiotic prophylaxis:** for selected patients at risk of infective endocarditis before invasive dental procedures * **Antiviral medications:** management of oral herpes or HIV-related conditions * **Antifungals:** for treating oral candidiasis (e.g., *nystatin, fluconazole*) * **Vaccination history review:** consider interactions with immunosuppressive medications or compromised immune states # **Pharmacological considerations in infectious disease management** - **Antibiotic prophylaxis:** for selected patients at risk of infective endocarditis before invasive dental procedures - **Antiviral medications:** management of oral herpes or HIV-related conditions - **Antifungals:** for treating oral candidiasis (e.g., *nystatin, fluconazole*) - **Vaccination history review:** consider interactions with immunosuppressive medications or compromised immune states Take home message * Microorganisms cause disease through **pathogenicity** and **virulence** * Understanding **transmission routes** is essential for infection control in clinical settings * **Vaccines** are a vital preventive tool for both practitioners and patients * **Pharmacological** **interventions** (antibiotics, antifungals, antivirals) support infection management * Clinical decisions must always **balance** **efficacy, patient comfort, and safety** # **Take home message** - Microorganisms cause disease through **pathogenicity** and **virulence** - Understanding **transmission routes** is essential for infection control in clinical settings - **Vaccines** are a vital preventive tool for both practitioners and patients - **Pharmacological interventions** (antibiotics, antifungals, antivirals) support infection management - Clinical decisions must always **balance efficacy, patient comfort, and safety** Review A cartoon tooth spraying a cleaning solution on a virus or germ # **Review** References * Bowen WH, Koo H. Biology of *Streptococcus mutans*-derived glucosyltransferases: Role in extracellular matrix formation of cariogenic biofilms. *Caries Res*. 2011;45(1):69–86. Available from: https://www.sciencedirect.com/science/article/pii/S1882761617300066 * Kaiser GE. The ability to invade host cells. In: *Microbiology* [Internet]. LibreTexts; 2023 [cited 2025 Apr 10]. Available from: https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Kaiser)/Unit_3%3A_Bacterial_Pathogenesis/5%3A_Virulence_Factors_that_Promote_Colonization/5.3%3A_The_Ability_to_Invade_Host_Cells * Australian Commission on Safety and Quality in Health Care. *Options for implementation of preventing and controlling infections in primary care: dental practice* [Internet]. Sydney: ACSQHC; 2024 [cited 2025 May 3]. Available from: https://www.safetyandquality.gov.au/sites/default/files/2024-12/options_for_implementation_of_preventing_and_controlling_infections_in_primary_care_dental_practice.pdf * Tortora GJ, Funke BR, Case CL. *Microbiology: An Introduction, Global Edition*. 13th ed. Pearson; 2019 * Australian Commission on Safety and Quality in Health Care. *National Hand Hygiene Initiative Implementation Guide*. Sydney: ACSQHC; 2024. Available from: https://www.safetyandquality.gov.au/sites/default/files/2023-07/nhhi_implementation_guide_july_2023.pdf * Australian Technical Advisory Group on Immunisation (ATAGI). *Australian Immunisation Handbook* [Internet]. Canberra: Australian Government Department of Health and Aged Care; 2024 [cited 2025 Apr 10]. Available from: https://immunisationhandbook.health.gov.au/ # **References** - Bowen WH, Koo H. Biology of *Streptococcus mutans*-derived glucosyltransferases: Role in extracellular matrix formation of cariogenic biofilms. *Caries Res*. 2011;45(1):69–86. Available from: https://www.sciencedirect.com/science/article/pii/S1882761617300066 - Kaiser GE. The ability to invade host cells. In: *Microbiology* [Internet]. LibreTexts; 2023 [cited 2025 Apr 10]. Available from: https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Kaiser)/Unit_3%3A_Bacterial_Pathogenesis/5%3A_Virulence_Factors_that_Promote_Colonization/5.3%3A_The_Ability_to_Invade_Host_Cells - Australian Commission on Safety and Quality in Health Care. *Options for implementation of preventing and controlling infections in primary care: dental practice* [Internet]. Sydney: ACSQHC; 2024 [cited 2025 May 3]. Available from: https://www.safetyandquality.gov.au/sites/default/files/2024-12/options_for_implementation_of_preventing_and_controlling_infections_in_primary_care_dental_practice.pdf - Tortora GJ, Funke BR, Case CL. *Microbiology: An Introduction, Global Edition*. 13th ed. Pearson; 2019 - Australian Commission on Safety and Quality in Health Care. *National Hand Hygiene Initiative Implementation Guide*. Sydney: ACSQHC; 2024. Available from: https://www.safetyandquality.gov.au/sites/default/files/2023-07/nhhi_implementation_guide_july_2023.pdf - Australian Technical Advisory Group on Immunisation (ATAGI). *Australian Immunisation Handbook* [Internet]. Canberra: Australian Government Department of Health and Aged Care; 2024 [cited 2025 Apr 10]. 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