Several mechanisms have been proposed which may
explain how diabetes produces alterations in the organs
and tissues, including the periodontium. First studies
demonstrated that the advanced glycation end- products
(AGE) synthesized due to hyperglycemia, can convert
macrophages into cells with a destructive phenotype,
producing high levels of interleukin-1β, interleukin 6
(IL-6) and tumour necrosis factor- α (TNF-α). Moreover,
AGE have the capacity to increase the endothelium permeability
and express high levels of molecular adhesion
receptors. These changes could explain the greater susceptibility
to infections and the delayed wound healing
in diabetic patients (8). This depressed immune response
could explain why it may not be possible to eradicate
periodontal infection totally in diabetics after conventional
periodontal therapy. This might be one of the reasons
why antibiotics may be suggested with mechanical
therapy for diabetic patients, especially for uncontrolled
cases (7). By contrast, in trying to determine the capacity
of periodontal disease to adversely affect the control
of diabetes by influencing gylcemia levels, it has been
hypothesized that chronic low grade inflammations such
as this might result in insulin resistance (9).