Infectious Diseases
As has been discussed, most members of the indigenous flora are anaerobes. Anaerobes are likely to penetrate epithelium and given the relatively large surface area of combined periodontal pockets, more anaerobes are likely to enter the underlying connective tissue than facultative organisms. It has been previously claimed by Loesche and others. (1997) that because of the high pC>2 and Eh1 of these tissues, anaerobes are contained and rarely appear in the blood stream. Indeed, these organisms find the highly aerobic host cells so unfavourable that they rarely survive to enter the bloodstream. However, because most of these anaerobes are Gram-negative, their lipopolysaccharide can initiate events that may increase the circulating levels of cytokines, with possible adverse effects for the host (Beck and others 1998). Despite it being generally regarded that blood is a highly oxygenated medium in which oral anaerobes cannot survive for any length of time (Loesche and others 1995)...