Perio ch 2

Dehiscence

Resorbed area of bone over the facial surface of the root

saliva

Saliva provides protective influences that include: Lubrication Physical protection Cleansing Buffering Remineralization of teeth Antibacterial actions An increased incidence of both caries and periodontal diseases is also observed in individuals who have xerostomia (reduced salivary function).

periodontium

Structures that surround, support, and are attached to the teeth Includes: Gingiva PDL cementum alveolar bone

blood supply to periodontium is ?

Superior alveolar artery supplies the maxilla. Inferior alveolar artery supplies the mandible.

transeptal fibers (principal fiber)

span interdental space with ends inserted into cementum of teeth function- maintain relationship between teeth

how much hydroxyapatite makes up the inorganic components of cementum?

50%

cytokines

Cytokines are substances produced by stimulated immune cells. They assist in the development and regulation of immune effector cells, such as increasing the number of T cells to multiply their effects; they cause cell-to-cell communication and are, themselves, effector molecules. Cytokines have effects on all cells of the immune system and play a major role in both the pathogenesis of disease and healing.

frenum

Frenum and muscle attachments are present in the gingiva. Those located coronally in the attached gingiva are associated with narrow widths of attached gingiva.

fenestration

An opening, or window, in the bone covering the facial surface of a root or a boneless window between two adjacent roots that almost touch

auxilary cells

Basophils, eosinophils, and platelets all get involved in immune response they react to cytokines which are released by the lymphoid cells and phagocytes

Gradual remodeling of the alveolar bone includes:

Bone resorption by osteoclasts in response to pressure (push) along the mesial surfaces Bone deposition by osteoblasts in areas of tension (pull) along the distal surfaces

Cytotoxic reaction type 2

In type II (cytotoxic) reactions, antibodies react directly to antigens. Type II reactions result in the breakdown of tissue or blood cells. Cytotoxic reactions are not observed in gingival or periodontal diseases, but these reactions may be observed in areas where antibodies react directly with epithelial cell membranes, such as in pemphigus

Immune Complex-Mediated (Arthus)Reaction—Type III

In type III (immune complex-mediated) (Arthus) reactions, high levels of antigen persist in an area without being eliminated. This type of reaction occurs around small blood vessels, activates complement, and can cause extensive localized tissue damage. An example of a type III reaction is the response observed in skin tests for tuberculosis.

Cell-Mediatedor Delayed Reaction—Type IV

In type IV (cell-mediated) reactions, the reaction of antigens with the surface of T lymphocytes are related to this type of hypersensitivity. Once sensitized to an antigen, these lymphocytes can undergo blastogenesis (transformation), resulting in mitotic division and greatly increasing the number of immunocompetent (reactive) cells sensitized to the specific antigen. These reactions explain why, on a second exposure to an allergic agent such as a bee sting, the reaction can be greatly increased and possibly become life threatening.

Lymphocytes

Lymphocytes recognize and react to foreign molecules. Foreign molecules are termed antigens. Macrophages gather up antigens and present them to the lymphocytes for their destruction. Lymphocytes retain a memory of a specific antigen and will recognize it months or years later. Three types of lymphocytic cells are: 1. T lymphocytes (T cells) 2. B lymphocytes (B cells) 3. Killer or natural killer (NK) cells

macrophages

Macrophages are scavenger cells. STIMULATED BY COMPLEMENT REACTION. They engulf and digest bacteria. Macrophages produce enzymes and other substances that play a significant role in collagen destruction, which leads to the loss of periodontal tissues.

alveolar process is ? and is composed of what three components?

The alveolar process is an extension of the bone of the body of the mandible and maxilla The alveolar process is composed of: Alveolar bone, which makes up the cribriform plate encompassing the alveoli and adjacent cancellous bone Compact bone, which makes up the facial and lingual cortical plates of bone Trabecular and cancellous bone between the cortical plates and surrounding the alveoli

Gingiva is keratinized or parakeratinized and is commonly stippled. Nonstippled gingiva is also observed in healthy mouths. T/f?

both true

Physiologic mesial migration

is normal tooth movement.It allows the dentition to retain balance.

what cells are found in the stratified squamous epithelium of the oral cavity?

keratinocytes, merkel cells, langerhan cells, and melanocytes

Cancellous Bone

lies between the cortical plates and the alveolar bone, connecting them. It is also known as spongiosum. Less cancellous bone is found in the mandible than in the maxilla.

lymphotoxin or interferon do what?

lymphotoxin is important because it can stimulate bone and cartilage resorption interferon are special due to their antiviral properties

Compact bone

makes up the cortical plates on the facial and lingual sides of the jaws. The alignment of the teeth, angulation of the roots to the bone, and occlusal forces determine the height and thickness of the compact bone.

Mast cells

mediate the inflammatory response. Their stimulation results in increased vascular permeability, which advances the inflammatory response.

Alveologingival fibers (principal fiber)

radiate from periosteum to attached gingiva function- attach gingiva to underlying bone

Juntional 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. forms a layer that is 15 or 20 cells thick at the coronal end and narrowing to a few cells at the apical termination. Length in a healthy state ranges from 0.25 to 1.35 mm.

Gingiva is distinguished from the oral mucosa at the __________.

mucogingival junction

nerve supply of periodontium is ?

nerve supply is from the trigeminal nerve(CN #V) Branches of the nerves terminate in the periodontal ligament, the connective tissue, and on the surface of the alveolar bone. Nerve endings receive stimuli for:pain (nociceptors)position and pressure (proprioceptors).

Polymorphonuclear Leukocytes

neutrophils they are attracted to periodontal lesions, particularly acute lesions, through chemotaxis. PMNs make up approximately 70% of the leukocytes. PMNs phagocytize (digest) microorganisms, and they contain destructive substances that are extremely important in periodontal infections. PMNs contain granules that are filled with enzymes such as collagenase or elastase. These enzymes are released and cause tissue destruction when the PMN cells degranulate. Abnormalities in PMNs can lead to more severe periodontal disease if the cells are unable to perform their functions or lack specific granules.

Does the amount and type of pathogenic bacteria present in disease alone explain the variation seen in the degree of individual response?

no

Keratinization

occurs as keratinocytes migrate from basal layer to the surface - the cells become flattened and develop keratohyaline granules and produce a superficial layer that is similar to skin where no cell nuclei is present tip* in some cases the superficial layers some of the cells retain their nuclei = PARAKERATINIZED epithelium

Langerhans cells? merkel cells? Melanocytes?

part of phagocytic system assoc with tactile sensitivity produce melanin- remains within epithelium and give off pigmented look

Secondary gingival fibers

periostogingival - attach gingiva to bone interpapillary - support papillary gingiva transgingival - support marginal gingiva intercircular- maintain arch form semicircular- support free ginigva intergingival- support attached gingiva

PDL

provides suspensory cushion in the .1 to 1.5 mm space between the surface of the tooth and bone It is a connective tissue filled with fibers and cells - these cells are important because they generate pericementum and periosteum for the bone. Tip unusual formations can occur such as cementicles

Dentogingival fibers (principal fiber)

radiate from cementum into free gingiva and attached gingiva function - support the gingiva

Hypersensitivity (allergic) reactions are responses to foreign bacteria, viruses, or other substances. T/f?

t

Sharpey's fibers

the fiber bundles are attached to the cementum with brush like fibers

free gingiva

the unattached portion of the gingiva that surrounds the tooth in the region of the CEJ surface of free gingiva adjacent to tooth structure creates the Gingival wall of the sulcus .

sulcular epithelium

thin - nonkeratinized or parakeratinized - extends from oral epithelium into the gingival sulcus found from the height of gingiva to the JE juntional epithelium if healthy it is smooth and intact - and no RETE PEGS projecting into the connective tissue are noted. Usually 1-3 mm deep

alveoli

tooth sockets the bone lining the alveoli contains sharpeys fibers

Gingival or sulcular fluid increases with normal physiologic functions, such as mastication of foods, toothbrushing, increases in female sex hormones, and smoking, as well as after periodontal surgery. T/F? what makes up approx 92% of the cellular content of the fluid?

true Leukocytes

palatal tissue is the most keratinized tissue T/f? Cheek tissue is the least keratinized tissue in the mouth ? T/F?

true ; true

gingiva

visible component of the periodontium inside the mouth usually coral pink, pink, or pale pink

lamina dura

walls of the teeth sockets when viewed on radiographs it appears as radiopaque line around the roots of teeth also referred as the cribriform plate

what are characteristics of healthy gingiva

■ A shade of pale or coral pink varied by complexion and pigmentation. ■ A knife-edged gingival margin that adapts closely around the tooth. ■ Stippling, firmness, and minimal sulcus depth with no bleeding when probed.

Fiber bundles of the PDL

-Fiber bundles in the periodontal ligament are made up of collagen and spread throughout the periodontal ligament. -Fiber bundle functions include: -Attaching the tooth to the bone -Transmitting occlusal forces to the bone -Resisting occlusal forces ("shock absorber") -Protecting the vessels and nerves from injury

what are functions of pdl

-Tooth anchorage Fibrous tissue development and maintenance Calcified tissue development and maintenance Nutritive and metabolite transport Sensory functions, including touch, pressure, pain, and proprioception (displacement sensitivity)

The immune system is responsible for the body's reaction, which is called the ____ response.

HOST

what is location of a fully erupted health patients gingival margin?

0.5-2 mm coronal to CEJ

Antibodies (immunoglobulins) production involves what steps?

1.Macrophages process the antigen. 2.Macrophages then present the fragments to T cells, which interact with B cells. 3.B cells differentiate into plasma cells, which produce the antibodies. Antibodies are found in the blood, tissue fluids such as gingival fluid, and secretions .Human (antibodies) immunoglobulins (Ig) are divided into nine distinct classes on the basis of structural differences: IgG1, IgG2, IgG3, IgG4G, IgM, IgE, IgD, IgA1, and IgA2.

Development of disease in the periodontium depends on two factors:

1.Microbial assault from dental plaque biofilms 2.Host response When microbes assault, the cells in the host form an inflammatory reaction. Inflammation is protective in that it leads to the destruction of bacteria; however, it can also lead to tissue alteration and destruction in the host periodontal tissues. Inflammation may lead to irreversible changes in the periodontium, which is known as periodontal disease.

antibodies make up how much of the serum protein? Complement is made up of glycoprotein and proteins that account for about how much proteins in human serum? Are complements affected by immunizations like antibodies are?

20% 5% no -because they are proteins not immunoglobulins

complement

Complement is made up of proteins and glycoproteins whose functions include bacteriolysis (destruction of bacteria) and promotion of the immune response. Complement reacts with IgG and IgM, causing lysis and alteration of cell walls, which encourage phagocytosis. Complement also causes the release of histamine, increasing permeability of small blood vessels. Increased permeability permits migration of PMNs and increased phagocytic activity in the area. The reaction can also result in destruction of periodontal tissues.

Anaphylactic Reaction—Type I

In type I (anaphylactic) reactions, histamine is released. The response can be generalized or localized. Generalized reaction can be life threatening (e.g., food or drug allergies). Localized reaction can result in increased tissue destruction (e.g., the periodontium). Histamine is found in higher concentrations in chronically inflamed gingiva.

The inflammatory response includes:

Inflammatory cells Antibody reactions Antigen reactions Complement reactions Hypersensitivity (allergic) reactions

inflammatory cells

Inflammatory cells migrate to areas of the body when signaled by stimuli such as microbial influences This process is called chemotaxis In periodontal diseases, the inflammatory cells are attracted to the gingiva, connective tissue, periodontal ligament, and bone.

inflammatory cell funtions

Ingest and neutralize bacteria, which is called phagocytize. Secrete products that affect the permeability of blood vessels. Cause cell disintegration, which is referred to as lysis. Cause destruction of alveolar bone by inducing osteoclastic activity. Divide to increase their numbers in a process called blastogenesis.

Interleukin (cytokine)

Interleukins (IL) are cytokines that owe their names to their communication function between leukocytes.

Cementum

Is a calcified structure that covers the root surfaces of the teeth. Cementoblasts form cementum. Cementoblasts encased in cementum are called cementocytes. Is thinner at the cementoenamel junction and thickens as it progresses to the apex. Functions include (1) anchoring the teeth and maintaining occlusal relationships (by attachment of the PDL), and (2) providing a seal for the dentinal tubules. Contains Sharpey's fibers. Sharpey's fibers are the embedded portions of the fiber bundles that attach to the roots of the teeth. non vascularized!

sulcus depth

Normal sulcus depth, when measured by a periodontal probe, is 1 to 3 mm. The sulcular epithelium is intact in the healthy state, not ulcerated, and should not bleed on gentle probing.

Root proximity

Occurs when: Teeth erupt with roots that are very close together. Teeth are poorly aligned. Multirooted teeth are unusually and widely spread out.

What is the attached gingiva?

Part of the gingiva that is tightly attached to the bone by collagen fibers Width varies from individual to individual and from tooth to tooth. A thin band of attached gingiva is usually present in the posterior regions. Palatal attached gingiva blends into the palatal gingiva without demarcation.

Connective tissue found beneath the gingiva is ? and what two layers does it consist of ?

The connective tissue beneath the gingiva is called the lamina propria which is made of 2 layers: 1.Papillary layer, which is beneath the epithelium •Consists of papillary projections between the rete pegs. 2.Reticular layer, which extends to the periosteum Approximately 60% of the lamina propria is made up of connective tissue that is composed of collagen fibrils that form fiber bundles. Other elements of the lamina propria include cells such as fibroblasts, undifferentiated mesenchymal cells, mast cells, and macrophages, as well as blood vessels and nerves.

attachment aparatus

The periodontal ligament, cementum, and alveolar bone are referred to as the attachment apparatus.

Age-related changes that occur in the periodontium include:

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

what are the five types of cementum and what do they consist of?

acellular afibrillar - near CEJ no fibers and no cementocytes acellular extrinsic fiber- coronal third of root - sharpeys fibers and no cementocytes cellular mixed stratified- apical third of root and furcations- sharpeys / intrinsic fibers and it does have cementocytes cellular intrinsic fibers- areas of resorption- intrinsic fibers and also contains cementocytes intermediate cementum- near junction of cementum and dentin - contains no fibers and remnants of cementocytes

what are the three effector molecules that are stimulated after the antigen is recognized?

antibodies complements and cytokines

papillae

are gingiva that fill embrasures - proximal spaces created below the contact areas of the teeth Anterior- pyramidal posterior- col space

gingival epithelium is joined to underlying connective tissue by a _______lamina (300-400 thick). The ____lamina is joined to the connective tissues by _____. The connection between the free and attached gingiva and the underlying connective tissue occurs in the rdgdes of epithelium called ________

basal; basal; fibrils; rete pegs

oral epithelium

composed of attached gingiva the papillae and the outer surface of the free gingiva covers the crest of the gingiva, free gingiva, and the attached gingiva. function- protection and is typically parakeratinized

dentoperiosteal fibers (principal fiber)

course from cementum near the CEJ across to the alveolar crest function- anchor tooth to bone and protect pdl

circular fibers (principal fiber)

encircle entire tooth coronal to alveolar crest Function- support free gingiva

dentogingival unit is?

fibers from the connective tissue aid the attachment of the junctional epithelium to the root surface.

sulcular fluid or gingival crevicular fluid

flows from underlying connective tissues into the sulcus amount of fluid is small considered to be normal in healthy state Function: cleanse the sulcus, improves epithelial cell adherence to the tooth surface, and posses antimicrobial and immune properties

how is free gingiva distinguished by attached gingiva?

free gingival groove

what are the fiber bundles known as?

gingival ligament there are 5 principal fiber bundles and 6 minor fiber groups that make up the gingival ligament

basophils and mast cells contain what?

histamine - mediates hypersensitivity reactions byt may also enhance collagen destruction and bone resorption