DANB CDA Exam 111 Questions And Answers

One of the biggest concerns during office remodeling or construction is the potential environmental dissemination of microorganisms resulting in nosocomial infections. Nosocomial infections are those acquired while in a hospital or another medical facility, such as a dental office. Construction activity creates additional moisture and water in the area, which creates a favorable environment for certain microorganisms.

The bacteria present that are most likely to cause caries are mutans streptococci (Streptococcus mutans or Streptococcus sobrinus), which are acidogenic, aciduric, and tend to build up on the teeth. Mutans streptococci have enzymes called glucosyltransferases that break down sucrose into polysaccharide glucans and bind to cells encouraging further plaque formation and fructose which is ultimately processed into lactic acid.

Pulpitis, which is inflammation of the pulp of the tooth, is caused when caries spreads into the pulp region. Pulpitis can spread further to the apex or periapical region and in some cases to the adjacent facial tissues as cellulitis or inflammation of subcutaneous tissues. Pulpitis is generally treated endodontically by a root canal procedure, which is the removal of dead pulp tissue, killing and pulling out bacteria in the root canal and adding inert materials to the canals. Antibiotics may also be given.

Syphilis, caused by the spriochete Treponema pallidum, can initially show up as an open ulcer on the tongue or lip. However, it is a systemic disease, and if left untreated, can result in secondary patches on the mucous membranes of the oral cavity about 2-10 weeks after the initial lesion.

The two main systemic viral diseases that can result in oral lesions are chickenpox and infectious mononucleosis. The causative agent of chicken pox (as well as shingles in older individuals) is human herpes virus type 3, also known as vermicelli zoster virus. It is transmitted to droplet infection to the respiratory tract, the bloodstream, and eventually to the skin and other organs, possibly manifesting orally as vesicles.

One of the biggest concerns globally is the possibility of contraction of tuberculosis, a respiratory infection caused by Mycobacterium tuberculosis. Persons at greatest risk for contraction of tuberculosis are those in intimate and prolonged contact with an active carrier or individuals who have a compromised immune system.

The main fungus causing oral manifestations is the opportunistic yeast Candida albicans. It proliferates under certain opportune conditions such as depression of the immune system with HIV or leukemia, lengthy use of broad-spectrum antibiotics, mouth trauma usually from poorly fitting dentures, or transmission during birth. The possible oral manifestations are candidiasis or thrus, which are whitish lesions, and denture stomatitis, which appears as reddish regions.

Oral diseases of viral origin are primarily caused by some type of human herpesvirus or coxsackievirus. There are 8 types of DNA-containing human herpes viruses (HHV-1 to -8). Oral lesions known as cold sores or apthous ulcers are primarily caused by HHV1, types 1 and 2), and as infectious mononucleosis or hairy leukoplakia of the tongue by HHV-4 (Epstein-Barr virus).

Hepatitis B, C, and D viruses are bloodborne. Hepatitis C virus (HCV) is an enveloped single-stranded RNA flavivirus. Its incubation period is from one to five months, and its onset is usually insidious. The routes of transmission are similar to those for HBV except that about half of cases have been found to be related to intravenous drug abuse. Unlike HBV, most (up to 85%) of HCV-infected individuals go on to be chronic carriers of the virus and about 1/5 of them contract chronic liver disease, including hepatocellular carcinoma and cirrhosis. There is no current vaccine.

Hepatitis A virus (HAV) is a non-enveloped single-stranded RNA picornavirus. Acute infections almost never result in death. There is an available vaccine for HAV (usually suggested for those traveling to countries with inadequate sanitation) as well as antibody screening tests. The latter include anti-HAV, antibody to HAV, which can be found at onset of symptoms and endures throughout life, and IgM anti-HAV, which detects the IgM class of antibodies only present after recent infection.