The effect of tobacco smoking on the host defence system in connection with periodontal disease. This assignment discusses the effect of tobacco smoking on the host defence system in connection with periodontal disease on the basis of investigations concerning cytokines, adhesion molecules, leucocytes, immunglobulins and vascularisation. The assignment explores studies concerning e.g. TNF-a and IL-1 a and -ß which show both an increase and a decrease in the concentration of these in smokers. It is also found that smoking can have an influence on the concentration of endothelial ICAM-1 and soluble ICAM-1 and thus restrain the transportation of leucocytes through the endothelium. In some experiments, smoking is furthermore seen to have a restraining effect on the role of macrophages as antigen
presenting cells, the activation of lymphocytes and the production of immunoglobulins. The function of  olymorphonuclear cells is also found to be restrained in several investigations with respect to their mobilisation, transport through the endothelium and their fagocytosis of microbes. In addition, in most investigations,smoking is seen to cause vasoconstriction which results in reduced vascularization of the gingiva. The conclusion is that smoking has an important influence on the development of periodontal disease, and it is therefore essential that the dentist is capable of both informing his patients about the detrimental effects of smoking and motivating them to quit smoking.