19 AUG 2020

19 AUG 2020 · PERIODONTIUM 1 Gingiva 2 Attachment apparatus* a. Pdl b. Alveolar bone c. Cementum (has dead cells) acellular cementum PERIODONTAL TISSUE : (has living cells) a) Gingiva b) Periodontal ligament c) Alveolar bone PARTS OF GINGIVA  Normal range of gingival sulcus depth is- 2-3mm  Colour of normal gingiva is an interplay between – keratin layer, melanine, blood vessels, epithelial thickness.**  FREE GINGIVA – Also known as unattached / marginal gingiva. From the gingival margin till the free gingival groove / base of the sulcus. (sulcus is in healthy gums, whereas pocket is in unhealthy / diseased gums) KERATINIZED  ATTACHED GINGIVA- From free gingival groove (base of the sulcus) to the mucogingival junction. KERATIINIZED o Healthy one shows stippling. o Best views by drying the gingiva. o Highest width is seen in incisors-  Maxillary : 3.4-4.5  Mand - 3.3-3.9** o Narrowest seen in molars  Max 1.9mm  Mand 1.8mm  ALVEOLAR MUCOSA o From mucogingival junc to fold o Non keratinized  INTERDENTAL GINGIVA a) Anterior – pyramidal b) Posterior — col shape c) Midline diastema — triangular FREE GINGIVAL GROOVE MUCOGINGIVAL JUNCTION BIOLOGICAL WIDTH  Biological width — junctional epithelium + connective tissue = 2 mm***

19 AUG 2020 · ORAL MUCOUS MEMBRANE:- KERATINIZED MUCOSA  Hard palate  Gingiva (70% para & 30% ortho) NON – KERATINIZED (stratum cornea absent)  Soft palate  Floor of mouth  Alveolar mucosa  Sulcular epithelium  Buccal mucosa SPECIALISED MUCOSA  Dorsum of tongue LAYERS OF MUCOSA EPITHELIUM LAMINA LUCIDA BASEMENT MEMBRANE (contains TYPE IV COLLAGEN) LAMINA DENSA CONNECTIVE TISSUE  Basement membrane connections to epithelium  Via — desmosoms and hemidesmosomes LAYERS OF EPITHELIUM Stratum cornea (surface layer) Stratum granulosum Stratum spinosum Stratum basalis (innermost layer)  Most common epithelium – squamous epithelium  No blood supply  How does epithelium get Nutrition? By diffusion from connective tissue a) Stratum basalis – highly dividing cells b) Odland bodies (reserve bodies) – stratum spinosum c) Stratum granulosm – contains granules that get activated from enzymes and produce keratin for the cornea layer of the epithelium d) Stratum cornea – keratin deposition KERATINIZATION a) Para keratinized (with nuclei) — 70% gingiva b) Ortho keratinized (devoid nuclei) — 30% gingiva NON KERATINOCYTES:-  Free nerve cells  Melanocytes  Langerhan cells

19 AUG 2020 · CEMENTUM  With age cementum on root end become thicker & irregular.  This increase in the width of cementum is greater in the APICAL & LINGUAL areas.**  COLOUR o VITAL – YELLOW o NON – VITAL — GREY OR GREEN  Cementum starts formation from cervical area  Cementum in cervical2/3rd  acellular extrinsic fiber,  In coronal acellular intrinsic,  In apical mixed cellular  Acellular – cervical region A x C  Cellular – apex region C x A  Thickness o Thickest at apex o Thin at CEJ  Age changes – content increases with age at apex  SHARPEY’S FIBRES – connection from cementum to alveolar bone. Parallel to bone and parallel to cementum?  Transseptal fibers are Fibers which completely embedded in cementation and pass from cementum of one tooth to the cementum of adjacent tooth.  HYPERCEMENTOSIS o Low grade periapical infection o Excessive occlusal force, bruxism The end of PDL fibers that are embedded in the alveolar bone and cementum are called - Sharpey's fiber is the dominant type of fibers found in cementum. Nb: dental tissue similar to bone – DENTINE (histologically) not cementum

19 AUG 2020 · BONE  PDL attachment is to : alv. Bone proper or called bundle bone  The crest of INTERDENTAL BONE is said to be parallel to the marginal gingiva  Or you could also say it id parallel to the line drawn from the CEJ of adjacent teeth.  Now if the position of CEJ of the neighboring tooth is variable, then the bone will be angulated towards the line.*** PERIODONTAL LIGAMENT  Cells o Fibroblast o Osteoblast o Cementoblast o Cell rest of malassez Lateral periodontal cyst from rest of serres ,while apical periodontal cyst from rest of malassez.  Fibres o Collagen o Elastic fibres  Cementoblasts present in pdl  Cell rest of malassez seen commonly at apex FIBRES OF PDL  COLLAGEN 1,3,7  Most dental tissue type I collagen fibres o Eg: pdl,alveolar bone, cementum, gingiva, dentin o They are most abundant  Anchoring fibres are type 7, seen in pdl  Type 3 also seen in pdl Ageing OF PDL  Elastic fibres increase and cells decreases  Function of pdl  Formative, nutritive, anchorage, cushioning (type 7)

19 AUG 2020 · PRINCIPLE GROUP OF PDL FIBRES: a) Alveolocrestal fibres – prevents extrusion of teeth b) Horizontal fibres – prevents lateral movement of teeth c) Oblique fibres – withstands masticatory forces, most abundant QN. Periodontal ligament fibers in middle third of root is oblique. d) Apical fibres – absent in young permanent teeth , because of open apex e) Intraradicular fibres – absent in single rooted teeth TRANSEPTAL FIBRES  Transseptal fibers are Fibers which completely embedded in cementation and pass from cementation of one tooth to the cementation of adjacent tooth.  the only fibers present in cementum only  Not a pdl group of fibres  Responsible for orthodontic relapse  This fibre is removed in pericision(surgical Rx to prevent ortho relapse)  Dentogingival fibre — the 1st fibre lost during extraction  In pulp :- - Cell rich zone inner most pulp layer contain fibroblast  – Cell free zone rich in capillaries & nerve networks  - Odontoblastic layer contain odontoblast.

19 AUG 2020 · PATHOGENESIS  Subgingival plaque is the initiating factor her- the microorganism in it release toxins  Our immune system sends response in the form of white blood cells, cytokines, prostaglandins, Matrix Metalo Protein (mmp)  Then cause tissue distruction BLOOD CELLS All born / formed in bone marrow RBC  No nucleus  Life span is 120 days PLATELETS  No nucleus  Below 80,000 — no surgery possible  Below 50,000 — no injury at all o 50,000 cells/mg — critical count of platelets WBC  GRANULOCYTES o NEUTROPHIL  Predominant inflammatory cells in pdl pockets o BASOPHIL  Allergy o EOSINOPHIL  Allergy  Least abundant WBC  AGRANULOCYTES o T o B – plasm cells 1. NEUTROPHIL a. POLYMORPHO NEUTROPHIL LEUKOCYTES b. PMNL cells present in acute infection and suppurative cases-pdl abcess , while chronic lymphocytes. c. Most abundant WBC in pdl pockets d. Acute inflammatory cell e. It is the cell that will become defective in diabetes mellitus f. Destroys PDL membrane in periodontitis g. Diabetes condition, weak activity of PMNL h. Action – phagocytosis eg: macrophage OTHER NEUTROPHIL DEFECTIVE CONDITIONS:- i. Neutropenia j. Granulocytosis k. Chediak – Higashi syndrome l. Papillon – Lefevre syndrome m. Leukocyte adhesion deficiency n. DM most importantly! Phagocytosis is the process of engulfing particles. Chemotaxis is attraction of neutrophils to site of local injury. 2. CELLS OF SPECIFIC RESPONSE a. T cells b. B cell or Plasma cells i. Produce immunoglobins Ig G A M E ii. Most dominant in perio pockets. 3. INNATE IMMUNE CELLS a. Neutrophils b. Monocytes c. Macrophages d. Mast cells e. Dentrite cells 4. LANGERHANS CELL DISEASE a. Eosinophil infiltrate to pdl — cause early loss of 1° tooth

19 AUG 2020 · IMMUNOGLOBINS:- (produced by B lymphocytes) (G-A-M-E)  IgG — most abundant Ig in blood and in GCF — passive immunity through placenta  IgA — all secretion of body contains this eg: saliva (lacrimal) — passive immunity through milk (colestrum breast milk)  IgM — first Ig to reach site of infection  IgE — abundant in allergy and anaphylaxis

19 AUG 2020 · MMPS — MATRIX METALO PROTEINASES Most important proteinase involved in destruction of periodontal tissue EG: MMP – 8, MMP – 13 GINGIVAL CREVICULAR FLUID  GCF has most abundance of IgG  CONTAINS o Components of CT o Epithelium o Inflammatory cells o Serum o Microbial flora living there in the sulcus  More neutrophils to defend the gingiva.  Most drug concentration o 1st tetracycline/doxycycline o 2nd metronidazole  DOXYCYCLINE – similar to tetracycline QN Tetracycline cause brownish discoloration in all teeth & appear yellowish with UV light  Pedo —20mg  Therapeutic value — 100mg /day (Antibacterial dose)  Sub antimicrobial dose = 20mg — bacteriostatic at GCF

19 AUG 2020 · PLAQUE INDUCED GINGIVITIS:- STAGES ----------- FINDINGS ------------- CELLS INVOLVED --------------------------------------------------------------------------- INITIAL GCF ----- 1ST sign of gingivitis --- PMNL or neutrophils ACUTE ------------ bleeding on probing, definitive sign of gingivitis ---- T - lymphocytes CHRONIC / ESTABLISHED ----- edematous or fibrous – smokers plasma / B – lymphocytes (7- 21 days) ADVANCED -------- onset of PDL destruction plasma/B lymphocytes CONDITIONAL GINGIVITIS :-  All these plaque induced gingivitis  Systemic conditions — pregnancy, DM, Leukemia, puberty  PREGNANCY GINGIVITIS:-  P.intermedia – orange complex  Begins 2nd/3rd  Disappears in 9th month.  PREGNANCY TUMOUR  EPULIS GRAVIDIUM:— kind of Angio-granuloma or pyogenic granuloma (old name) ie bleeding on touch o Irritation of interdental papilla results in tumor like growth at papilla  Rx o Scaling  best time is 2nd trimester (remove irritant) NB: safest antibiotic in pregnancy – Amoxycillin *