(Tannerella forsythensis)

found deep in periodontal pockets and is ass. w/ aggresive periodontal disease

Bacteria attached to epithelium most detrimental tot he periodontal tissue.

Motile gram - & spirochetes

Lipopolysaccharide

(endotoxin)

Agents that are harmful or destructive to host cells

1. increase permeability of the epithelial lining
2. breakdown of collegen fibers in the gingival
3. promote apical migration of JE
4. widening of the intercellular space
5. diminished ability of immunoglobulins and other body proteins

Know the different classifications of bacteria based on their shape. 

Cocci-round, spherical.  Can be single cells or be in groups, clusters:  Micrococci, Diplococci, Streptococci, Staphylococci

Know the different classifications of bacteria based on the structure of the cell wall. 

Gram +: thick single cell wall retains purple when stained

Gram -: Double cell walls don't retain purple stain

Know the different classifications of bacteria based on their O2 requirements. 

Know the different classifications of bacteria based on their O2 requirements. 

Aerobic: need air

Anaerobic: don't need air

Facultative: Can live w/ or w/o air

Be able to discuss the importance of biofilm in the oral cavity as it relates to the initiation and progression of periodontal disease.

Attachment of bacteria to the surface

Primary colonizers attach to the pellicle

   Initial colonization

2^nd colonization

                                     Formation of mature subgingival plaque biofilm. 

Have an understanding of the various attachment modes of colonizers to the pellicle and to each other.

Initial attachment of bacteria to pellicle

Within a few hours the after the pellicle forms bacteria begin to adhere to it. attach.  The bacteria attatch to the pellicle  with hundreds of hairlike structures called fimbriae.

Secondary colonization: Extracellular Slime Layer and Microcolony

This extracellular slime layer helps to anchor bacteria to the tooth surface and provides protection for the attatched bacteria

Mature biofilm: Mushroom shaped Microcolonies

                                Attatched by a narrow base

Distinguish between supragingival and subgingival plaque biofilm in relationship to composition, nutrient source and ease of removal.

◦       80% H2O

◦       20% solids-mainly bacteria

◦       Cocci, rods, filaments extracellular microbial products (endotoxins), salivary constituents

–   Microflora more anaerobic, more gram -, more motile, more asaccharolytic

Know the primary and 2^nd pathogens in relationship to etiology of periodontal disease.

◦       Attach to the tooth from the gingival margin apically and is associated with calculus formation and root caries

◦       Inner core mainly gram+.  Examples:  streptococcus sanguis, actinomyces viscosus

◦       Apical portion dominated by gram- rods with some filaments present.

What type of bacteria would you ass. with Epithelial-attached ?

AKA-epithelium associated plaque,

◦       Examples:  P. gingivalis, A. A.,

Epithelial-attached -AKA-epithelium associated plaque 

◦       Invade gingival connective tissue

◦       Most injurious to periodontal tissues. 

◦       Bacterial toxin levels greatest in this type

◦       Associated with different forms of periodontitis

Tooth-attached the most difficult

 Unattached plaque the easiest

◦       Free floating

◦       Gram – rods and spirochetes

Know the distance that biofilm and calculus can be from the alveolar to cause destruction.  Be able to apply this principle.

Distance from biofilm to the bone is never less than .5mm and never more than 2.7mm

These parameters limit the destructive ability of bacterial toxins on the bone

Discuss virulence factors and how biofilm distance applies to periodontal pathogens.

Harmful proteins released from the bacterial cell that act on the host from a distance. 

 IE. Aa Actinobacillus actinomycetemcomitans

Exotoxin

Lipopolysaccaride (LPS)

A major component of the gram - bacteria

the LPS is onlt relaesed when the cell dies and the wall is broken up

The host reposes to this is what causes tissue destruction

Agents that are harmful or destructive to host cells by...

1.increasing sulcular epithelium

2. increasing collagen fiber breakdown

3. increase apical migration of JE

4. increase widening of intracellular space

5.  decrease the hosts ablity to defend its self with Ihg and protiens

Phagolysosome

plasma cells---secreting antibodies

coat bacteria flagging them for for phagocytosis

Compounds secreted by immune cells that activate the body's inflammatory response

• cytokins
• prostaglandins
• matrix metalloprpteinases

Powerful mediators produced by immune cells that influence the behavior of other cells

Transmits Infomation

Series of powerful inflammatory mediators

D,E,F,G,H,I

Matrix metalloproteinases

MMP

Opsonization of pathogens

Host response of inflammatory process

           Understand the prime purpose of the human immune system and how this relates to the oral cavity

•          The body’s defenses are employed with the purpose of eliminating the invading bacteria, not the preservation of the tooth or its supporting periodontal tissue

1. The cell wall of a phagocytic cell adheres to the bacterium
2.    The phagocytic cell surrounds the bacterium
3.    The bacterium is surrounded by a phagocytic vesicle called the phagosome
4.      Lysosome granules within the phagocyte fuse with the phagocytic vesicle and a phagolysosome is formed
5.    The bacterium is digested within the phagolysosome.
6.        The phagocytic cell releases the contents of the phagolysosome into the tissue.  Note that the lysosomal enzymes and other microbial products are released from the neutrophil or macrophage after the phagocytosis or when the host cell dies; once released the lysosomal enzymes cause damage to the local tissues in the same manner that they destroyed the bacteria.  This is the main cause of tissue damage due to infection by pathogenic organisms. 

1. Heat: Increase of blood at the site
2. Redness: Increase blood at the area
3. Swelling: Fluid accumulation at the site in the form of leukocytes/plasma
4. Pain: Excess fluid build-up puts pressure on nerves
5. Loss of function: Swelling and pain

Creation of the membrane attack complex, a protein unit which is capable of puncturing the cell membrane of certain bacteria.  This is done by forming pores in the cell membrane of these certain bacteria, a task accomplished by the membrane attack complex

• Initiate most of the alveolar bone destruction in periodontitis
• Trigger increased osteoclast activity
• Increase the permeability and dilation of the blood vessel, leading to redness and edema of the connective tissue

1. tooth attached
2. epithelial attached
3. unattached

• Streptococus sanguis
• Actinomyces visosus
• These are generally gram + on the inner care and gram -  the outer core.  Usually attached by calculus formation and root caries

• P. gingivalis
• A.A
• gram - and spirochetes

• free floating biofilm-bacteria
• usually found at the bottom of a pocket surounded by leukocytes

• A.A.
• P. gingivalis
• Treponema denticola

1. Chondroitin sulfatase
2. Collagenese
3. Proteases
4. Elastases

These act on the host cells at a distance by releasing cytotoxic agents

1. Actinobacillus actinomycetemcomitans
2. Porphymonas gingivalis
3. Tanerella forsythia
4. Treponema denticola

1. Prevotella intermedia
2. Campylobacter rectus

1. Stretococcus intermedius
2. Prevotella nigrescens
3. Peptostreptococcus micros
4. Fusobacterium nucleatum
5. Eubactium species
6. Eikenella corrodens