# The Link between Periodontal Disease and Oral Cancer--A Certainty or a Never-Ending Dilemma?
###### Abstract  
Periodontal disease can have a substantial systemic influence on the body that extends beyond the oral cavity and can lead to local inflammation, bone damage, and tooth loss. A great number of studies suggest that periodontitis and oral cancer are linked, however it is unclear if specific periodontal bacteria promote the development of systemic illness. The mediators of the relationship between those two pathologies are still being discovered, but the research findings indicate the existence of a correlation. Additional research, including confounding factors, is needed to strengthen this link. periodontal disease; oral cancer; tooth loss +
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one country to another [17; 18]. As the world's population ages, periodontal disease has become a serious public health concern according to the US Centers for Disease Control and Prevention, and can cause speech impairment, low self-esteem, and a lower quality of life [19; 20]. Clinical studies conducted by [PERSON] et al. on the association of marginal periodontal disease with age estimated that 15% of people between the ages of 31 and 50 years and 30% of those over 50 years develop severe chronic marginal periodontitis [21]. [PERSON] and [PERSON] mentioned in their study that 20% of the population of France aged between 35 and 65 years is affected by chronic marginal periodontitis [22]. In the United States, more than half of the 18-year-old population has an incipient form of periodontal disease and 75% of the population over 35 years have various forms of periodontal disease [23]. The severity of periodontal disease is also variable. According to some studies, between 30% and 50% of these diseases are mild, and 5-15% are severe and generalized [24; 25]. Many etiologic factors have been attributed to periodontal disease, both local and general. Given this, the following factors were incriminated: dental biofilm, surface morphological changes of the teeth, dental arches or temporomandibular joint (TMJ) disorders, occlusal and muscular condition, and general systemic factors. Following significant research, it has been discovered that the microbial component plays the most important role in the development of periodontal disease in its destructive form, with the other factors being favorable or predisposing [26]. The microbial etiology of periodontal disease is unanimously accepted today, but of the more than 500 microbial species that can form the bacterial biofilm, only a small part are involved in the pathogenesis of periodontal disease [27]. Thus, the presence in the bacterial biofilm of certain specific microorganisms, which can produce substances with a destructive role for periodontal tissues, is one of the necessary conditions for the development of periodontal disease. By histological investigation, [PERSON] and [PERSON] observed activation of the acquired immune system, which includes T cells and B cells, in periodontitis-affected donors in 1976 [28]. Since the 1990s, advances in molecular biology have uncovered a variety of molecular processes underpinning periodontitis pathogenesis. [PERSON] and [PERSON] discussed the link between periodontal bacteria and the host response, as well as the creation of different mediators during inflammation and periodontal tissue death [29]. Current data suggest that a small group of predominantly Gram-negative anaerobic or microaerophilic bacteria in the biofilm are frequently associated with initiation and progression of PD. Organisms strongly involved as etiological agents include _Porphyromonas gingivalis (P. gingivalis), Aggregatibacter actinomycetemcomitans_ (_A. actinomycetemcomitans_) and _Tannerella forythia_ (T. forsythia_) [30]. The bacterial aggression represented by antigens, lipopolysaccharidesaccharides, and other virulence factors stimulates the host response, which consists of gum-limited disease (gingivitis) or the onset of periodontitis. The oral microbiota and other physical stimuli produced by mastication are continuously acting on the periodontal tissue.