PERIODONTOLOGY

1. أستاذ . د .رائد عزيز LEC.6 2019 PERIODONTOLOGY

2. Host defense mechanism In gingivitis, periodontitis, the development of the disease depends on the Interaction between the resident microbiota and host response. In other types of P.d.disease., such as desquamative gingivitis, the lesions frequently result from a host response.

3. Inflammatory cells, molecules and processes chemotaxis is the directed movement of a cell along a chemical gradient, as a response to chemical signals (chemotaxins) from multiple sources, After attraction of the cells to the area they phagocytose bacteria and remove damaged tissue.

4. Mast cells:- Contain cytoplasmic granules that contain: • Histamine. • Heparin . • Bradykinin. all of which are released into the gingival tissues and cause:- Vasodilatation. Increased vascular permeability. Bone resorption.

5. Neutrophils • The neutrophils the engulf(phagocytosis) and kill bacteria and neutralize other noxious substances. (Protective effect) • Neutrophils may also cause tissue destruction because their granules also contain lysozyme, collagenase, and elastase. ((Destructive effect))

6. Macrophages:- • The efficiency of bacterial phagocytosis by the macrophages is enhanced by the reaction of the antibody with the antigen and subsequent complement activation. Protective • Macrophages are also important because they secrete interleukin-I (IL-I), IL-6, IL-8, IL-10, tumor necrosis factor γ (TNF- γ). Both Pr,&DES.

7. They also produce A- Prostaglandins---(BONE RESORPTION) B- Collagenase in response to 1- stimulation by bacterial endotoxin, 2- immune complexes, or 3- cytokines..Destructive effects • Macrophages collagenase may play an important role in collagen destruction in diseased periodontal tissues.Destructive

8. Antibodies:- Are glycoproteins, are found in blood, tissue fluid, and are the effectors of humoral immunity. ((Formed by plasma cells)) The following table summarizes the possible role of antibodies in inflammation:

10. Opsonization:- Coating a particle with recognizable molecules to enable phagocytic ingestion. Human immunoglobulin is divided into 5 classes. These are IgG, IgM, IgA, IgE, and IgD

11. Serum complement system: The serum complement system is composed of more than 20 serum proteins, that when activated, have potent biological activity. The system is important in both inflammation and immunity.

12. Biologic effects of complement:

13. Cytokines: The complex interaction among: • lymphocytes, • inflammatory cells, • and other cellular elements in connective tissue are mediated by a series of low- molecular weight proteins called (cytokines).

14. Lymphocytes, fibroblasts and macrophages produce : IL-1:It has the following functions: • stimulation of the production of endothelial adhesion molecules to begin the inflammatory process. • Activation of phagocytosis. • Production of prostaglandins by fibroblasts and osteoclasts.

15. IL-4:causes: • activation and division of B-cells • promotion of immunoglobulins • it is a growth factor of mast cells.

16. interferons: • are cytokines usually associated with antiviral activity. • It is secreted by T- cells • Enhance phagocytosis, • Causes bone resorption.

17. 3-Lymphotoxin (LT): is produced by activated T-cells. It activates leukocytes and it is cytotoxic to gingival fibroblasts. 4-Migration inhibitory factor (MIF): inhibit the migration of macrophages from an area of inflammation, so that increasing the population of macrophages in that area. .

20. THE END

21. EXAM