𝐃𝐞𝐧𝐭𝐚𝐥 𝐁𝐚𝐜𝐭𝐞𝐫𝐢𝐚𝐥 𝐈𝐧𝐟𝐞𝐜𝐭𝐢𝐨𝐧𝐬

Pathogenic bacteria are bacteria that can cause infection. This article deals with human pathogenic bacteria. Although most bacteria are harmless or often beneficial, several are pathogenic. One of the bacterial diseases with the highest disease burden is tuberculosis, caused by the bacterium Mycobacterium tuberculosis, which kills about 2 million people a year, mostly in sub-Saharan Africa. Pathogenic bacteria contribute to other globally important diseases, such as pneumonia, which can be caused by bacteria such as Streptococcus and Pseudomonas, and foodborne illnesses, which can be caused by bacteria such as Shigella, Campylobacter, and Salmonella. Pathogenic bacteria also cause infections such as tetanus, typhoid fever, diphtheria, syphilis, and leprosy. Koch's postulates are criteria designed to establish a causal relationship between a causative microbe and a disease.

Dental infections originate in the tooth or its supporting structures and can spread to the surrounding tissues. When facial structures are compromised the infection tends to originate from necrotic pulp, periodontal pockets, or pericoronitis. Dental infections have always been common and were one of the leading causes of death hundreds of years ago. The London England Bills of mortality in the 1600s reported teeth infections as the 5th or 6th leading cause of death. In 1908 it was believed that dental infections were associated with a mortality of 10 to 40% . Fortunately, due to improved dental hygiene, modern dentistry, and antibiotics, dental infections are rarely life-threatening today.

Etiology

Dental infections most commonly occur when bacteria invade the pulp and spread to surrounding tissues; this can be due to dental caries, trauma, or dental procedures.

Periodontal infections caused by periodontal pathogens first involve the gingival tissues causing gingivitis and, over time, periodontitis. The periodontal disease mostly results from poor or ineffective dental hygiene leading to plaque and calculus accumulation and subsequent inflammation of tissues that support the teeth, alveolar bone, periodontal ligament, and cementum. The etiology of periodontitis is multifactorial; while bacteria initiate them, the clinical presentation and outcome of the different forms of the disease are in the end determined by the inflammatory response and modifying and predisposing factors. The disease progression seems to be regulated by environmental and genetic factors specific in each patient.

Streptococcus mutans is considered as the primary etiologic agent of dental caries, an infectious disease. This pathogen can access the bloodstream during dental procedures, causing opportunistic systemic infections. Thus, bacteremia, through the adhesion to the endocardium, is involved in infective endocarditis and peripheral arterial disease.

Epidemiology

It is estimated that 13% of adults seek dental care for dental infection or toothache within four years and that 1 per 2600 head of the population in the United States is hospitalized due to dental infections. More than 1 in 5 people have untreated dental caries, and 3 in 4 people had at least one dental restoration during their life. Periodontitis is also common, with estimations that 35% of all Americans age 30 to 90 are afflicted.

More than 1 in 5 people have untreated dental caries, and 3 in 4 people had at least one dental restoration during their life. Periodontal disease is also common, with estimations that 35% of Americans age 30 to 90 are afflicted.

Furthermore, the prevalence of dental caries varies significantly by socioeconomic factors. Untreated dental caries were more than 2.5 times as common in those living 100% below the poverty level (41.9%) relative to those living 200% above the federal poverty level or higher (16.6%). The prevalence of dental caries is also dynamic during the patients' lifetime. Dental caries are present in 90% of adults and 42% of children ages 6 to 19 years. Dental caries did not appear to vary much with age except that adolescents age 12 to 19 were found to have a lower rate of untreated dental caries even when compared to children ages 5 to 11.