Education, Infectious Diseases, Point of Care

Infectious Diseases in Dentistry: Causes and Precautions

Author Chandana Balasubramanian , 29-Jun-2023

Most people go to the dentist to fight cavities, gum disease, and pain from infections. But many do not know that dentists take precautions to keep their patients safe from infectious diseases in dentistry. While some infections are mild, others can be severe, leading to other issues. For example, the HSV-1 virus causes cold sores and HPV and is linked to oral cancer. In this post, we will look at common infectious diseases at the dentist’s clinic, including bacteria, viruses, fungi, and protozoa. We will also focus on effective infection control measures, starting from hand hygiene and the right way to sterilize dental instruments to minimize infections.


In this article, we will explore common infectious diseases in dentistry and how they can be prevented.


Bacterial infectious diseases in dentistry

Bacteria play a crucial role in oral infections, with various species being implicated in different conditions. This section will discuss the most common bacterial infections encountered during dental procedures and their impact on oral health.

Streptococcus mutans: dental caries

Streptococcus mutans is the main cause of tooth decay, also known as dental caries. Millions of people worldwide suffer from tooth decay. The Streptococcus mutans bacteria thrives on sugars found in food particles left on teeth after eating, producing acids that dissolve tooth enamel over time. While regular dental cleaning does help minimize this infection, regular oral hygiene practices like regular brushing and flossing are needed to reduce S.mutans levels and reduce the risk of cavities.

Porphyromonas gingivalis – periodontal disease:

Another bacteria commonly associated with infectious diseases in dentistry is Porphyromonas gingivalis. This microorganism contributes significantly to gum disease or periodontal disease because it can invade gum tissue, leading to inflammation, bleeding gums, bad breath, and eventually tooth loss if left untreated. Regular professional cleanings at dental facilities can help manage P. gingivalis populations for better overall gum health.

Other bacteria causing dental infections

  • Actinomyces spp: This group of bacteria has been linked to root canal infections and the formation of dental abscesses. Actinomyces israelii or Actinomyces gerencseriae are responsible for causing most infections and live between the teeth and gums. The infection they cause is known as actinomycosis. An actinomycosis infection can lead to large abscesses in the mouth that can spread to other parts of the body.
  • Prevotella intermedia: This bacterium is often found in periodontal pockets and has been implicated in gum disease progression. Dental healthcare teams should be aware of its presence when treating patients with periodontitis.
  • Fusobacterium nucleatum, Treponema denticola, and Tannerella forsythia: Fusobacterium nucleatum is a normal part of the human oral flora (group of bacteria and fungi that our body needs for our daily needs). A bacterial imbalance or overgrowth can cause gum disease development and may contribute to more severe cases if not adequately managed through professional cleanings and an at-home oral care routine.


Key Takeaway: Bacterial infections are a significant concern in dentistry, with various species causing different diseases. Streptococcus mutans is the primary cause of dental caries, while Porphyromonas gingivalis can lead to periodontal (gum) disease.

Proper infection control measures during dental procedures and at-home oral care routines can help maintain a healthy environment for teeth, gums, and oral cavities.


Viral infections and oral health

Many viruses contribute significantly to infectious diseases in dentistry, impacting both patients and dental teams. Common viral infections that can affect oral health include HSV-1, HPV, and HBV.

Herpes Simplex Virus Type-1 (HSV-1): cold sores

Herpes simplex virus type-1, also known as HSV-1, is a highly contagious virus that causes herpes labialis or “cold sores.” These painful blisters typically form around the mouth but can appear inside the mouth as well. The virus is transmitted through direct contact with infected saliva or skin lesions, posing risks for both patients and dental professionals. Rescheduling appointments during active outbreaks can minimize transmission risk.

The human papillomavirus (HPV) is another significant source of infectious diseases in dentistry. HPV strains associated with oral cancer are particularly common in the base of the tongue, tonsils, and throat. Dental professionals should be aware of this association when examining their patients’ oral cavities for signs of malignancy. Regular check-ups and awareness about HPV vaccines may help prevent disease.

Hepatitis B virus (HBV): an occupational hazard for dental workers

Hepatitis B virus (HBV) is a bloodborne pathogen that poses an occupational hazard for dental workers. This is because the virus can be transmitted through infected needles (needlestick injuries) or contaminated surfaces. Infection risk can be reduced through strict infection control measures and vaccinating dental healthcare teams against HBV.

How to lower the risk of bacterial infectious diseases in dental care

  • Hand hygiene: Regular handwashing with soap and water, as well as using alcohol-based hand sanitizers before and after patient contact, helps prevent viral transmission
  • Personal protective equipment (PPE): Wearing appropriate PPE such as gloves, masks, eye protection, and gowns reduces exposure risks.
  • Vaccination: Ensuring all dental professionals are vaccinated against hepatitis B protects both staff and patients from this potentially serious illness.
  • Sterilization & disinfection: Proper sterilization or disinfection of instruments between patients minimizes cross-contamination risks associated with infectious diseases in dentistry like HBV.


Taking these precautions seriously will help maintain a safe environment in a dental setting, protecting both patients and healthcare professionals from various viral infectious diseases in dentistry.

Key Takeaway: Viral infections like HSV-1, HPV, and HBV pose a significant risk to patients and dental healthcare workers. Preventive measures like rescheduling appointments during active outbreaks and encouraging regular check-ups for early detection of oral cancer associated with HPV are important.  Strict infection control measures, including hand hygiene, PPE use, and proper sterilization and disinfection, are necessary to minimize the risk of transmission in dental facilities.


Fungal oral infections

Bacteria and viruses are often the primary focus when discussing infectious diseases in dentistry, but fungal organisms can also contribute to oral infections. One such organism is Candida albicans, which can cause opportunistic infections like candidiasis. Opportunistic infections are those that are more severe in people with weak or compromised immunities. For example, immunocompromised individuals undergoing chemotherapy or HIV-infected patients receiving antiretroviral therapy treatment regimes are susceptible to fungal infections like Candida albicans. Additionally, contaminated water lines and dental equipment can serve as potential sources of infection.

Candida albicans fungal infection 

Under normal circumstances, Candida albicans is a common fungus that resides in the human body without causing harm. However, when the host’s defenses are weakened or disrupted by factors such as sickness, drugs, or medical interventions, this fungus has the potential to become a pathogen. When this occurs, Candida albicans have the opportunity to overgrow and cause various types of infections, including oral thrush or candidiasis, which presents with white patches on the tongue and inner cheeks accompanied by pain and difficulty swallowing. Immunocompromised people are especially prone to these opportunistic infections because of their weakened ability to combat pathogens.

Risk factors for getting a fungal infection at the dentist

  • Weakened immune system: Individuals with compromised immunity due to conditions like HIV/AIDS or those undergoing cancer treatments have a higher risk of developing fungal infections.
  • Prolonged use of antibiotics: Antibiotics disrupt the balance between beneficial bacteria and fungi within our bodies; this prolonged usage may lead to an overgrowth of Candida albicans.
  • Poor oral hygiene: Inadequate oral care can create an environment conducive to fungal growth and infection.
  • Contaminated dental equipment: Improper sterilization or disinfection of dental instruments may introduce fungi into the patient’s mouth, increasing their risk for infection.


How to lower the risk of fungal infections in dentistry

To help reduce the likelihood of fungal infection, patients and healthcare professionals should take preventive measures such as:

  • Practicing and educating patients about good oral hygiene habits
  • Proper sterilization techniques must be employed by all members of the dental team to ensure that infectious agents are not transmitted between patients through contaminated equipment.
  • Antifungal medications may be prescribed as prophylaxis against potential infections during routine dental procedures for those who are at increased risk due to immunosuppression or other factors.


Fungal infections can be quite serious if left untreated, so it is important to recognize the signs and risk factors associated with acquiring them.

Key Takeaway: Fungal organisms like Candida albicans can cause opportunistic infections in dentistry, particularly among immunocompromised individuals. Risk factors for acquiring fungal infections include weakened immune systems, prolonged use of antibiotics, poor oral hygiene, and contaminated dental equipment. Good oral hygiene practices, awareness, and proper sterilization techniques are crucial to reduce the incidence of fungal infections in dental settings.


Protozoan parasites linked to oral diseases

Although less common than bacterial or viral agents, protozoan parasites can be linked to oral infections. One such parasite is Entamoeba gingivalis, which has been found in the gums of patients with severe periodontitis (gum inflammation and infection), which suggests that the parasite may contribute to the disease’s progression.

Entamoeba gingivalis: periodontitis

Research studies have identified E. gingivalis as a potential contributor to oral infections, particularly in individuals with poor oral hygiene practices or compromised immune systems. This amoebic parasite lives within the oral cavity and feeds on bacteria present in dental plaque. Some experts believe that the existence of this organism can worsen inflammation and damage to tissue connected with gum diseases like periodontitis.

Risk factors for protozoan infections

E. gingivalis tends to be more commonly detected in people living in developing countries where access to adequate dental care may be limited. Risk factors associated with acquiring an infection include:

  • Poor oral hygiene habits: Inadequate brushing and flossing can lead to increased plaque buildup, creating a favorable environment for parasitic colonization.
  • Weakened immune system: Individuals who are immunocompromised due to conditions like HIV/AIDS or undergoing chemotherapy treatment are at higher risk for opportunistic infections by pathogens such as E. gingivalis.
  • Periodontal disease: The presence of periodontitis can facilitate the colonization and growth of protozoan parasites within the oral cavity.


To reduce the likelihood of contracting a protozoan infection, proper oral hygiene is necessary, including regular brushing, flossing, and dental visits. Healthcare professionals should be aware of the risks associated with these infections and take necessary steps to ensure prevention and treatment.

Diagnosing and treating Entamoeba gingivalis infections

The diagnosis of an E. gingivalis infection typically involves a microscopic examination of saliva or plaque samples collected from affected individuals. Treatment options may include antiprotozoal medications like metronidazole or tinidazole, together with improved oral hygiene measures to help control inflammation and reduce parasite burden within the mouth.

Key Takeaway: Protozoan parasite Entamoeba gingivalis has been found in periodontal pockets (gums) of patients with severe periodontitis, exacerbating inflammation and tissue destruction associated with the disease. Poor oral hygiene habits, weakened immune systems, and the presence of periodontitis are all risk factors for acquiring an infection; maintaining good oral hygiene practices and seeking appropriate medical care can help minimize these risks.


Infection control in dental care

Strict infection control measures are essential to prevent the spread of infectious diseases in dentistry. These include proper hand hygiene practices, the use of personal protective equipment (PPE), sterilization or disinfection of instruments and surfaces between patients, and safe disposal of sharps waste materials. Sharps are needles, syringes, lancets, and any other medical device used to puncture or cut skin.

Hand hygiene before and after patient contact

Proper hand hygiene is key to reducing the spread of infectious diseases within dental clinics. Healthcare workers should take precautions to clean their hands with soap and water or apply an alcohol-based sanitizer before donning gloves, after removing them, and between patient contacts. Additionally, dental teams must ensure that they do not touch any non-sterile surfaces while wearing gloves to prevent cross-contamination.

The importance of PPE use in dental clinics

Personal protective equipment (PPE), such as masks, goggles or face shields, gowns or lab coats, caps or head covers, shoe covers, and gloves, play a vital role in protecting both healthcare professionals and patients from exposure to potentially harmful pathogens during dental procedures. Dental teams should always wear appropriate PPE according to established guidelines when performing tasks involving contact with bloodborne pathogens like the hepatitis B virus.

Sterilizing dental instruments

  • Steam Autoclaving: This method uses high-pressure steam at temperatures above 121°C to kill microorganisms on heat-resistant instruments like metal forceps and scalers.
  • Dry Heat Sterilization: Suitable for heat-sensitive materials, this technique involves heating instruments to temperatures between 160°C and 190°C for a specified duration.
  • Chemical Sterilants: These are liquid solutions that can be used to sterilize heat-sensitive items such as plastic trays or rubber dams. Common chemical sterilants include glutaraldehyde, hydrogen peroxide, and ortho-phthalaldehyde (OPA).


In addition to instrument sterilization, dental teams should also disinfect surfaces like countertops and chairs using appropriate surface disinfectants following each patient visit. This helps reduce the risk of cross-contamination from one patient to another.

Safe disposal of sharps waste materials

Dentist offices generate a significant amount of sharps waste materials such as needles, syringes, scalpel blades, and broken glassware. It is essential that all sharps waste is disposed of in puncture-resistant containers specifically designed for this purpose. Dental workers must adhere strictly to local regulations regarding proper disposal methods for these hazardous wastes.

Key Takeaway:  Strict infection control measures are necessary in dentistry to prevent the spread of infectious diseases in dentistry. Dental teams must practice proper hand hygiene, use personal protective equipment (PPE), sterilize instruments and surfaces between patients, and dispose of sharps waste materials safely. Failure to adhere to these protocols can lead to cross-contamination and potential transmission of harmful pathogens like hepatitis B virus.



Infectious diseases in dentistry are a significant concern for healthcare professionals and patients alike. Dental inflammation, periodontal disease, oral candidiasis, HSV-1 infections, HPV, and job-related exposures are all potential hazards to oral health. Understanding the global prevalence rates of these conditions and how bacteria, viruses, fungi, and parasites can spread is important. Also, dental healthcare professionals can take steps to prevent transmission and manage symptoms effectively. Strategies such as vaccination against HBV and promoting good oral hygiene practices can help reduce the risk of infectious diseases in dentistry.



The GIDEON difference

GIDEON is one of the most well-known and comprehensive global databases for infectious diseases. Data is refreshed daily, and the GIDEON API allows medical professionals and researchers access to a continuous stream of data. Whether your research involves quantifying data, learning about specific microbes, or testing out differential diagnosis tools, GIDEON has you covered with a program that has met standards for excellence.


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Chandana Balasubramanian

Chandana Balasubramanian is an experienced healthcare executive who writes on the intersection of healthcare and technology. She is the President of Global Insight Advisory Network, and has a Masters degree in Biomedical Engineering from the University of Wisconsin-Madison, USA.

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