quality:corruption, linguistic:voice_change, structural:expansion, information:filtering
Oral bacteria have evolved mechanisms to sense their environment and evade or modify the host. Bacteria occupy the ecological niche provided by both the tooth surface and mucosal epithelium. Factors of note that have been found to affect the microbial colonization of the oral cavity include the pH, oxygen concentration and its availability at specific oral surfaces, mechanical forces acting upon oral surfaces, salivary and fluid flow through the oral cavity, and age. Interestingly, it has been observed that the oral microbiota differs between men and women in conditions of oral health, but especially during periodontitis. However, a highly efficient innate host defense system constantly monitors the bacterial colonization and prevents bacterial invasion of local tissues. A dynamic equilibrium exists between dental plaque bacteria and the innate host defense system. Of particular interest is the role of oral microorganisms in the two major dental diseases: dental caries and periodontal disease.