Chapter 2 Periodontium

Dentogingival

-cementum to free & attached gingiva; support gingiva

Cells attracted to areas of the body by stimuli such as microbial influence or trauma are referred to as A. Cytokines B. Blood cells C. Chemotactic Cells D. Inflammatory Cells

D. Inflammatory Cells

Cellular-

T-cells, NK cells, PMNs, macrophages that make direct contact with bacteria to kills MO's.

three types of lymphocytes

T-lymphocytes B-lymphocytes NK cells

EFFECTOR MOLECULES

ANTIBODIES COMPLEMENT CYTOKINES

5 classes of antibodies/immunoglobulins based on structural differences

IgM IgE IgD IgA IgG

What are rete pegs?

Ridges/projections of epithelium that connect gingival to underlying connective tissue. Think of these as increasing surface area for attachment. Cause Stippling to Occur

Mast Cells

Stimulated by tissue injury, contact with IgE, and complement. Produce histamine and heparin Best known for role in allergy and anaphylaxis

Periodontal disease is caused by both the type of bacteria assaulting the oral cavity AND the way the individual's body (host) response to the bacteria

TRUE

Cementum Thickness at CEJ is

20-50um ; thinner at CEJ

Gingival Connective Tissue Primary Fiber Groups

Circular Dentogingival Dentoperiosteal Alveologingival Transseptal

What is sulcular fluid and what are its other names?

Flows from underlying CT to between epithelial cells and into sulcus Know as gingival and crevicular fluid

A narrow (@1.5mm) cuff of gingiva around the coronal portion of each tooth.

Free marginal gingiva

What makes up the periodontium?

Gingiva Periodontal Ligaments Cementum Alveolar Bone

Cementum characteristics

Has Sharpey's fibers (Type II & IV) No blood or nerve tissue (no pain for scaling) Anchors tooth, maintains occlusal relationships, and seals dentinal tubules

5 Major Groups of PDL Fiber bundles

Alveolar crest group (lateral force/tooth retention in socket) Horizontal fiber bundles (attach root to bone across PDL space) Oblique group (transfer occlusal stress to bone) Apical fiber bundles (attach tooth apex to bone) Interradiular fiber bundles (attach tooth from furca to bone, only in multirooted teeth)

Alveolar process and its components?

Alveoli Compact bone Cancellous bone Variations: -Dehiscences -Fenestrations Attachment apparatus- PDL, cementum and alveolar bone

Humoral -

B cells (with T-cell help) producing antibodies that bind with bacterial cell

Macrophages

Begin as monocytes in blood; They are protective in that they phagocytize bacteria, but they produce enzymes and other substances that may play a role in collagen destruction leading to a loss of periodontal disease

Cytokines Regulate important body processes

Cell production and growth Activation of cells Inflammation Immunity Cell & tissue repair Chemotactic effect on immune cells Include IL, TNF, INF, GF and CSF Pro-inflammatory, anti-inflammatory or chemotactic Most are found locally, not systemically Produced as needed, not stored

Auxiliary Cells

Cells that get involved in host response because of interaction with cytokines: Basophils Eosinophils Platelets

The window of bone in healthy bone structure covering the surface of the root is called a dehiscence. The dehiscence is a significant structure in periodontal disease A. Both Statements are true B. Both statements are false C. The first statement is true, the second is false D. The first statement is false, the second is true

D. The first statement is false, the second is true

Biological Width

Distance between base of sulcus/top of JE and top of crestal bone

Antibodies-immunoglobulins

Macrophages present antigens to T-cells; T-cells interact with B-cells, which then differentiate into plasma cells, which produce antibodies. Antibiotics are found in body fluids; highly specific and sensitive

Saliva helps in

Maintains PH Contains enzymes and antibodies that protect CT and kill bacteria Minerals help remineralize tooth Coagulation factors help clot blood and protect wounds from MO's

Immunology

The study of the immune system and host response

Type IV

cell-mediated, delayed (reaction of antigens to T-cell surface)/ 2nd beesting can be life threatening. Huge response when t lymphocytes have memory of the antigen and cause increased tcell numbers to fight antigen. Can become life threatening.

Dentoperiosteal-

cementum (near CEJ) actross alveolar crest; anchor tooth to bone, protect PDL

Cytokines are sometimes referred to as IL- interleukins because they

communicate with leukocytes, high numbers of specific Ils related to severe PD

Type III

immune complex (Arthrus) wheal/flare-TB test/ occurs when high levels of antigen persist in area, leading to complement reaction near small blood vessels.

Loss of salivary function results in

increased periodontal disease, increased caries, and reduced wound healing.

Gingival Connective Tissue is called

lamina propria

LYMPHOTOXIN-

large response to plaque bacteria stimulate bone and cartilage destruction

Cells in sulc. Fluid =

leukocytes (PMN's)92%; keep plaque from entering CT

Auxiliary cells:

mast cells, basophils, eisonophils, & platelets

IgG-

most abundant, in blood and tissue fluids, neutralizes MO toxins and enhances phagocytosis. 80% of total serum Im, passes placental barrier.

Dehiscences-

resorbed bone on facial of root , cleft-like

IgA

secreted in tears, saliva; activates complement and interferes with bacterial adhesion to tissues; may affect dental caries.

Fenestrations-

opening or window in bone on facial of bone, circumscribed

Alveologingival-

periosteum to attached gingiva; attach gingiva to bone

IgD

present in low amounts and triggers immune response

IgE

present in low amounts, leads to histamine release and is responsible for acute allergic reactions.

INF-Interferon

protects body from viruses

Cytokines

substances produced by the stimulated immune cells Secreted by T cells and activated B cells

The periodontal ligament fiber group that runs from the cementum to the crystal bone is termed A. Alveolar crest B. Apical C. Horizontal D. Interradicular E. Oblique

A. Alveolar crest

B lymphocytes come from the liver, spleen, and bone marrow. B Lymphocytes are important in the antigen-antibody response A. Both Statements are true B. Both statements are false C. The first statement is true, the second is false D. The first statement is false, the second is true

A. Both Statements are true

Blood/Nerve Supply of Periodontium

Blood promotes high metabolism of area Capillary-venule prexus near JE is active in host defense Innervation of JE and free & attached gingiva provide tactile and possibly pain responses during probing

Epithelium is divided into

(oral, sulcular, junctional)

PMN's also called

Neutrophils

What distance is gingival margin from CEJ in mouth that has not experienced gingival disease?

.5 to 2 mm coronal to the CEJ

Healthy attached gingiva appears

Attached gingiva color is pink, stipples and keratinized. Width is 1-9 mm with ave. 4mm in maxilla and 3.6 mm in mandible.

Effector Molecules

Antibodies, Complement, Cytokines

Cementum Thickness at apex is

50-200 um; thickest at apex

5 common functions of the PDL

Anchor tooth Develop and maintain fibrous tissue (cushion) Develop and maintain calcified tissue (PDL cells form pericementum for cementum and periosteum for bone) Transport nutritives and metabolites Provide sensation (touch, pressure, pain, proprioception)

The presence of gingival fluid will increase A. After mastication of soft foods B. Before periodontal surgery C. With inflammation D. After menopause

C. With inflammation

First Line of Defense

Congenital Immunity Nonspecific, so it's fast Involves phagocytosis and acute inflammation

The attachment apparatus is made up of A. Lamina dura and alveoli B. Periodontal ligament fiber bundles C. Elements of the junctional epithelium D. Periodontal ligament, cementum, and alveolar bone E. Sharpey's fibers, cementum, and periodontal ligament fiber bundles

D. Periodontal ligament, cementum, and alveolar bone

Inflammatory cells perform all of the following functions EXCEPT one. Which is the EXCEPTION A. Lyse cells B. Phagocytize bacteria C. Remove damaged tissue D. Reduce osteoclastic activity

D. Reduce osteoclastic activity

Main components of the gingiva

Epithelium Mucogingival Junction Connective Tissue Gingival fluid

Sulcular Epithelium

Extension of OE (margin to JE) into sulcus (usu.1-3mm long) Forms gingival wall of sulcus (non-keratinized)

Host Response Components

Inflammatory Cells Effector Molecules Hypersensitivity Reactions (allergic)

Complement

Is 10% of proteins in serum. Reacts simultaneously with IgM and IgG—encouraging phagocytosis. Bacteria that develop a coating protect themselves from this Mediates degranulation of mast cells, leading to histamine release and blood vessel permeability; this leads to release of PMN's and phagocytic activity in tissues Reaction is sequenced, cascading, and grows until complete. Small amount of antigen can cause big immune response.

Inflammatory Cells

Lymphocytes PMN's Mast cells Macrophages Auxiliary cells

What is physiological drift?

Normal tooth movement over lifetime (1cm); teeth move toward midline if don't wear retainers...leads to crowding.

Inflammation is

PROTECTIVE and DESTRUCTIVE

Gingival Connective Tissue Secondary Fiber Groups

Periostogingival Interpapillary Transgingival Intercircular Semicircular Intergingival

Alveolar Process

Radiographically, the lamina dura appears as a radio-opaque line around the roots of the teeth.

Lymphocytes

Recognize foreign molecules (antigens) presented to them by macrophages Develop a memory for specific antigens that lasts months-years

Mucogingival junction

The transition area from loosely-attached tissue (mucosa) to firmly-attached tissue (gingiva).

Aging and the Healthy Periodontium

Thinning gingiva Decreased keratinization of the epithelium Flattening of the rete pegs More dense connective tissue Periodontal ligament with a more irregular structure Thickened cementum Alveolar bone with a less regular surface Less orderly insertion of collagen fiber

Hypersensitivity Reactions (allergic)

Type I Anaphylaxis Type II Cytotoxic Type III Immune complex Type IV Cell-mediated/ delayed

Hypersensitivity Reactions

Type I Immediate Reaction Type II Immediate Reaction Type III Immediate Reaction Type IV Delayed Reaction

Width of Attached Gingiva

Widens with age

Chemotaxis is process that

alerts inflammatory cells that an invasion has begun.

Too much histamine:

anaphylactic shock

Type I

anaphylaxis (histimine release)/ Chronic gingivitis/ like food allergy, can be localized or generalized, can be life threatening, chronic gingival inflammation has high histamine levels, allowing more inflammatory cells to reach area.

IgM -

appears early in immune reaction and then levels lower, activates complement, found in bloodstream.

Oral Epithelium

attached gingiva, papilla, and outer surface of free gingiva. protective (keratinized)

Transseptal-

span interdental space with ends inserted in cementum; maintain relationship between teeth

Type II

cytotoxic (antibodies react with epithelium)/pemphigus-cause tissue breakdown or cell breakdown/ not see in PD, but in diseases where antibodies react directly with epithelial membranes.

Circular-

encircle tooth coronal to alveolar crest'; support free gingiva

Compounds in sulc. Fluid=

flucose

Junctional Epithelium

separates the periodontal ligament from the oral environment. It is made up of nonkeratinized stratified squamous epithelial cells that adhere to the tooth structure. Its function is to protect the attachment of the tooth to the surrounding tissues.