[Periodontal disease--specific or nonspecific infection?]

The concept of a non-specific etiology of periodontal disease has been predominant during the last century. It was believed that this disease was caused by the normal oral microbial flora and dependent on the state of the immune system of the host. The specific plaque hypothesis, which is currently discussed, claims that specific oral bacteria cause different forms of periodontal disease. High counts of these bacteria have been found in association with different forms of periodontal disease. These bacteria have also been found to have stronger pathogenic potential than other members of the oral microbiota. It is concluded that there are different forms of periodontal disease and that some of these forms are probably opportunistic infections associated with different microbial etiologies.