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FACT SHEET: Tuberculosis (also known as TB; caused by Mycobacterium tuberculosis complex bacilli bacteria which attack the lungs in about 70% of cases, but can attack any part of the body)

Date of Publication: March 11, 2013

Is the initiation of non-invasive dental hygiene procedures* contra-indicated?

  • Potentially; this depends whether the patient/client has latent TB infection (which is not contagious to others and therefore there is no contraindication) OR the patient/client has active TB disease of the lungs, respiratory tract, or oral cavity (in which cases there is a contraindication until the patient/client is treated and becomes non-infectious).
  • In cases of active pulmonary (lung) or respiratory tract tuberculosis (which pose contagious risk by airborne spread to others, particularly when the patient/client has a cough) or active oral tuberculosis (which is rare, but which poses a small risk of direct transmission), deferral is indicated until the patient/client is no longer contagious to others nor has oral lesions which interfere with non-invasive procedures.
  • A positive tuberculin (Mantoux) skin test does not necessarily indicate active TB disease (particularly if the test was performed as part of a routine screening process in an asymptomatic individual, rather than for diagnostic or contact investigation purposes). If the tuberculin positive patient/client has no signs or symptoms of TB coupled with a negative chest X-ray, the patient/client likely has latent TB infection, rather than active TB disease. Latent TB infection is not a contraindication to non-invasive nor invasive dental hygiene procedures.

Is medical consult advised?  

  • Yes. Persons suspected of having TB disease should be referred to a physician for work-up, which will include a medical history, physical examination, test for TB infection (tuberculin skin test [TST]1 or TB blood test2), chest X-ray, sputum collection, and other tests as appropriate. A medical consult is particularly urgent where active pulmonary TB disease is suspected (see below) given the infectious risk to others. Depending on their risk status, persons diagnosed with latent TB infection are sometimes prescribed a prophylactic anti-tuberculous antibiotic (e.g., isoniazid [INH] for 6 to 12 months) to reduce the likelihood of future conversion from latent infection to active disease.3 Persons diagnosed with active pulmonary TB are usually treated with several anti-tuberculosis medications for 6 to 9 months and are closely monitored. Drug resistance is a growing concern in many countries, although a lesser concern in Canada.

Is the initiation of invasive dental hygiene procedures contra-indicated?**

  • Yes, for active tuberculosis (as per Ontario Regulation 501/07 made under the Dental Hygiene Act, 1991). 

Is medical consult advised? 

  • Yes, see above.

Is medical clearance required? 

  • Yes − specifically for active tuberculosis.

Is antibiotic prophylaxis required?  

  • No (pertaining to prophylaxis for invasive dental procedures, as distinct from chemoprophylaxis for latent TB infection). 

Is postponing treatment advised?

  • Yes, if patient/client presents with active pulmonary/respiratory/oral TB; see above. Elective dental treatment should be deferred until the patient/client has been declared non-contagious by a physician. Urgent dental care for a person with suspected or active tuberculosis should be provided in a facility that has the capacity for isolation from airborne infection and a respiratory protection program in place; this includes use of appropriate respiratory protection, such as fitted N-95 respirators.

Oral management implications

  • Mode of transmission for active pulmonary or respiratory tract TB is airborne via droplet spread from one person to another via coughing, sneezing, speaking, or singing. The tubercle bacilli may be inhaled by others and cause infection. Active TB is most contagious when TB bacilli are found in the infected person’s sputum (phlegm).
  • TB transmission to workers in healthcare settings has been documented. If you think you have been exposed to someone with active TB disease, contact your physician or nurse practitioner.
  • When entering a room where it is known that a patient/client has active untreated or incompletely treated pulmonary TB, healthcare professionals should wear personal respiratory protective devices capable of filtering submicron particles (fitted N-95 respirator). Standard precautions are insufficient to prevent transmission of the Mycobacterium tuberculosis, and ordinary surgical/procedure masks are not designed to protect against airborne transmission of M. tuberculosis.
  • If a patient/client with signs/symptoms suggest of active tuberculosis presents to the dental hygiene office, that person should be promptly removed from the vicinity of other patients/clients or staff and be instructed to wear a surgical/procedure mask and immediately referred for medical care. 
  • Effective antimicrobial therapy for active pulmonary TB usually eliminates communicability within 2 to 4 weeks, although M. tuberculosis may be still cultured from sputum.4
  • In the case of oral TB (see below), it is possible, but unlikely, for oral health professionals to contract infection through contact with living tubercle bacilli. Direct invasion through mucous membranes or breaks in the skin may rarely occur.
  • Various anti-tuberculosis drugs should prompt careful choice of analgesics. For patients/clients taking isoniazid, acetaminophen should be avoided (due to hepatotoxicity). Aspirin (ASA) should avoided in patients/clients taking streptomycin or amikacin (due to kidney toxicity). 
  • While a tuberculosis vaccine (BCG) exists, it is not widely used in Canada and the USA (beyond select populations at elevated risk, such as certain First Nations and Inuit populations) given the relatively low prevalence of TB in these countries, as well as issues associated with the vaccine itself. Thus, BCG immunization is not generally considered a preventive measure for Ontario healthcare workers, but may be considered on an individual basis in at-risk settings.
  • A baseline tuberculin skin test may be indicated for healthcare workers at ongoing elevated risk of contracting tuberculosis. A two-step baseline TST is indicated for healthcare workers who will undergo tuberculin skin tests at regular intervals.5
  • A person with a “positive”6 tuberculin skin test and no signs/symptoms of active disease is not contagious to others and cannot transmit TB.

Oral manifestations

  • While active TB usually affects the lungs, TB bacilli can spread hematogenously (i.e., via the blood) to other parts of the body, including bones such as the mandible and maxilla. Tuberculous osteomyelitis can result from bony involvement of the mandible or maxilla. 
  • While uncommon, tuberculous lesions of the oral cavity do occur. Lesions of the oral mucosa are usually secondary to pulmonary disease, whether via hematogenous spread or via sputum-borne organisms entering mucosal tissue through small breaks in the surface.
  • While lesions may occur at any site on the oral mucous membrane, the tongue is most commonly affected, followed by the palate, lips, buccal mucosa, gingiva and frenula. The typical tuberculous lesion is a chronic, indurated, irregular, superficial or deep, painful, nonhealing ulcer, which tends to increase slowly in size. More rarely, mucosal lesions show swelling or fissuring without obvious ulceration. Tuberculous gingivitis is another unusual manifestation of TB. 
  • Pharyngeal involvement results in painful ulcers, which may cause dysphagia, odynophagia (painful swallowing), and voice changes. 
  • Involvement of the submandibular and cervical nodes (usually as a result of ingesting the microbe in non-pasteurized milk) causes enlargement of these nodes. This is called scrofula (tuberculous lymphadenitis). 
  • Of the various anti-tuberculosis drugs, rifampin in particular can cause oral manifestations, such as increasing incidence of infection, delayed healing, and gingival bleeding.

Related signs and symptoms

  • Tuberculosis is an infectious, chronic granulomatous disease, typically classified as latent (inactive) TB infection (LTBI) or active TB disease (pulmonary and/or extrapulmonary).  
  • About one-third of the world’s human population is infected with TB, mostly in less-developed countries. In 2017, an estimated 10 million people worldwide fell ill with tuberculosis.  
  • Canada has one of the world’s lowest rates of active tuberculosis, with 1,796 cases reported in 2017. Of these cases, about 72% were foreign-born, 17% were Canadian-born Indigenous, and 7% were Canadian-born non-Indigenous.  
  • Symptoms of active TB disease include: 
    • a bad cough that lasts 2–3 weeks or longer;
    • chest discomfort;
    • coughing up blood or sputum;
    • general weakness;
    • fatigue;
    • unintentional weight loss;
    • decreased appetite;
    • chills;
    • fever; and
    • night sweats.
  • In addition to the lungs, tuberculosis may affect any organ or tissue, including the lymph nodes, pleura, pericardium, kidneys, bones and joints, larynx, middle ear, intestines, peritoneum, eyes, brain, and spinal cord. Disseminated, or miliary, TB involves the whole body. 
  • If not treated properly, active TB disease can be fatal. 
  • Certain population groups in Canada have an increased risk of latent TB infection, including:
    • people who have come into close contact with individuals with known or suspected TB (e.g., family members or people sharing living spaces);
    • people with a history of active TB who received inadequate treatment;
    • people living in communities with high rates of latent TB infection or disease (e.g., some First Nations and Inuit communities and immigrant and refugee populations from endemic countries in Asia, Africa, Latin America, the Caribbean, Eastern Europe, and Russia);
    • the poor, especially the urban homeless; 
    • residents of long-term care and correctional facilities; and
    • persons who work with any of the above groups (e.g., healthcare workers and correctional staff).
  • While most people who have latent TB infection never go on to develop active TB disease (10% lifetime risk in adults), persons at elevated risk for the development of TB disease (including reactivation of the primary lesion which was previously walled off) include:
    • persons who became infected with TB bacteria in the last 2 years;
    • persons with HIV infection;
    • persons with other health problems that compromise the body’s ability to fight infection (e.g., diabetes, chronic kidney failure, or head and neck cancer);
    • babies and young children;
    • persons being treated with immunosuppressive drugs;
    • persons who abuse alcohol or use illegal drugs;
    • elderly people;
    • persons who were inadequately treated for TB in the past; and
    • persons with a chest X-ray showing signs of old TB.

References and sources of more detailed information

Date: January 28, 2013
Revised: May 10, 2020


1 A tuberculin skin test is also referred to as a Mantoux or PPD (purified protein derivative) test.
2 TB blood test = whole blood interferon gamma release assay (IGRA)
3 In 2019, the Centers for Disease Control and Prevention changed its previous recommendations to encourage treatment for all U.S. healthcare personnel with untreated LTBI, unless treatment is contraindicated.
4 According to the Centers for Disease Control and Prevention, in healthcare settings patients/clients can be considered non-contagious to others when they meet all of the following three criteria:

  • they have three consecutive negative acid-fast bacilli (AFB) sputum smears collected in 8- to 24-hour intervals (one should be an early morning specimen);
  • they are compliant with an adequate treatment regimen for two weeks or longer; and
  • their symptoms have improved clinically (for example, they are coughing less and they no longer have a fever).

5 In 2019, the Centers for Disease Control and Prevention changed its previous recommendations to state that no routine serial TB testing is recommended at any interval for U.S. healthcare personnel after baseline in the absence of a known exposure or ongoing transmission.
6 A “positive” TST is defined as a certain number of millimetres of induration (hardness) in the transverse diameter on the forearm, according to certain risk criteria.

* Includes oral hygiene instruction, fitting a mouth guard, taking an impression, etc.
** Ontario Regulation 501/07 made under the Dental Hygiene Act, 1991. Invasive dental hygiene procedures are scaling teeth and root planing, including curetting surrounding tissue.