Periodontics Part 2

Question 1

Plaque Formation Steps

Answer 1

1. Pellicle Formation
   * seconds
   * consists of glycoproteins & proline-rich proteins= attachment sites for bacteria
2. Adhesion & Attachment of bacteria
   * Minutes
   * Initial adhesion: weak reversible Van Der Waals& electrostatic forces
   * Strong irreversible attachment of adhesin molecules on early colonizers and host pellicle receptors
3. Colonization & plaque maturation
   * 24-48 hrs
   * Coadhesion: Primary colonizers provide new receptors for other bacteria to attach
   * Shift from Facultative gram (+) to anaerobic gram (-)

Question 2

Phases of Bacteria in plaque formation

Answer 2

Pellicle:
* glycoproteins, proline-rich proteins
* attachment sites for initial bacteria

Primary (early) Colonizers:
* Streptococcus except salivarus & actinomyces
* Feed on sugar & carbon from saliva/food

Secondary (late) Colonizers:
* P. Intermedia, P. Gingivalis, T. Denticola, Capnocytophaga, Campylobacter
* Feed on amino acids

Fusobacterium Nucleatum:
* bridging microorganism
* bind to primary & secondary colonizers

Question 3

Biofilm

Answer 3

Fluid Channels
* allows nutrients to pass through plaque

Quorum Sensing
* communication b/w bacteria in a biofilm
* encourage growth of beneficial species
* discourage growth of competing species

Biofilm bacteria more RESISTANT TO ANTIMICROBIALs than planktonic or free-swimming bacteria

Question 4

Red Complex

Answer 4

Associated w/ BOP & deeper pockets
* P. Gingivalis
* T. Denticola
* T. Forsythia

Question 5

Orange Complex

Answer 5

Before red complex
supports plaque maturation

• Fusobacterium
• Prevotella intermedia
• Campylobacter rectus

Question 6

Plaque Hypotheses

Answer 6

3:
Non-specific
* more plaque=more disease
* Any bacterial species

Specific
* Specific bacteria=Disease

Ecological (most accurate)
* certain bacteria + host factors (smoking, diabetes)=change environment->favor pathogenic

Question 7

A. Actinomycetemcomitans

Answer 7

• causes Aggressive Periodontitis
• Leukotoxin:

Question 8

P. Gingivalis

Answer 8

• Cause Chronic Periodontitis

Red complex

Secondary/Late colonizer

Question 9

T. Denticola

Answer 9

• Causes ANUG/ANUP
• Penetrate epithelium and Connective Tissue
• part of red complex
• secondary/Late colonizer

Question 10

T. Forsythia

Answer 10

• Nonmotile, gram (-) rod
• part of red complex
• Protease that cleaves immunoglobulins and complement factors

Question 11

P. Intermedia

Answer 11

• Causes pregnancy gingivitis
• part of orange complex
• Secondary/Late colonizer

Question 12

C. Rectus

Answer 12

• part of orange complex
• motile, gram (-) rod
• Polar flagellum

Question 13

F. Nucleatum

Answer 13

• Nonmotile, gram (-) rod
• part of orange complex
• The “Bridge” bacteria
• induces apoptosis of leukocytes and release of tissue-damaging substances from leukocytes

Question 14

Actinomyes

Answer 14

• healthy gingiva
• causes root caries

Question 15

S. mutans

Answer 15

• coronal/enamel caries

Question 16

S. Salivarius

Answer 16

• most common oral bacteria
• found on tongue

Question 17

Pseudomonas, Staph

Answer 17

• Implants

Question 18

Calculus

Answer 18

LOCAL FACTOR
* Mineralized dental plaque 1-14 days
* NOT destructive but allows biofilm attachment (plaque)

Question 19

Supragingival vs subgingiva calculus

Answer 19

Supragingival Calculus
* white/yellow
* mineralization via saliva
* occurs near salivary duct openings

Subgingival Calculus
* dark (Brown/Black)
* mineralization via GCF

Question 20

Materia Alba

Answer 20

Soft white cheeselike
*easily displaced by water spray

unorganized accumulation of
* bacteria
* salivary proteins
* Food Debris
* desquamated epithelial cells, and food debris

Question 21

Extrinsic Stains

Answer 21

primarily an esthetic concern
* Does not cause gingival inflammation

Question 22

Orange Extrinsic Stain

Answer 22

• anterior teeth
• poor OH

Question 23

Brown Extrinsic Stain

Answer 23

• Drinking dark-colored beverages
• Poor OH

Question 24

Dark Brown and Black Extrinsic Stain

Answer 24

• Tobacco

Question 25

Yellow-brown extrinsic stain

Answer 25

* Chlorhexidine (CHX) * Stannous Fluoride

Question 26

Black thin lines on cervical 1/3 extrinsic stain

Answer 26

Healthy Mouth--> Iron Consumption

Question 27

Green and yellow extrinsic stain

Answer 27

* anterior teeth * poor OH * **Chromogenic bacteria**

Question 28

Bluish-green extrinsic stain

Answer 28

* occupational exposure to metallic dust

Question 29

Local factors contributing to Periodontal Disease

Answer 29

* Calculus * Materia Alba * Malocclusion * Faulty Restorations * Appliances * Self inflicted injuries

Question 30

Malocclusion

Answer 30

* Crowding- plaque retentive area * Prominent roots & teeth w/high frena-gingival recession * Mesial Drift or extrusion due to missing teeth-->food inmpaction & plaque retention

Question 31

Faulty Restorations

Answer 31

Plaque Retention: * overhanging margins * open margins * rough surfaces * ope contacts **Overcontoured restorations** are WORSE for gingival health than undercontoured-->form plaque retention areas, hard to clean

Question 32

Subgingival Margins

Answer 32

Even if not FAULTY, Associated with: * plaque accumulation * gingival inflmmation * deeper pockets

Question 33

Appliances

Answer 33

RPDs * Increased mobility of abutment teeth * Increased plaque accumulation Orthodontic Therapy: * increase plaque retention * create excessive forces on the periodontium * Must establish Periodontal health before starting tx Oral Jewelry: can result in * recession * pocket formation * bone loss

Question 34

Self-Inflicted injury

Answer 34

Aggressive horizontal brushing cause: * tooth abrasion * gingival recession Improper use of tooth picks & fingernail biting can damage gingival tissues

Question 35

Neutrophils

Answer 35

* first line of defense * most important cells in controlling bacterial challenge & destroying periodontal tissue * Chemotaxis to periodontal pocket * Phaygocytosis MMP-8 (Neutrophil collagenase): * most important proteinase in destruction of periodontal tissues * tetracycline inhibits

Question 36

Neutrophil Abnormalities

Answer 36

1. Defective Neutrophil Chemotaxis leads to aggressive periodontitis Has to be just right to prevent tissue destruction * to much neutrophil activity=self inflicted tissue destruction * To little-->unchecked microbial challenge=tissue destruction

Question 37

Proinflammatory Mediators

Answer 37

IL-1: Bone resorption IL-6 PGE2 TNFa: Activate Macrophages **MMPs** * matrix metalloproteinase * destroy collagen * Protain-ase=eats proteins

Question 38

Pathogenesis of Gingivitis

Answer 38

Stage 1: * Initial Leasion * 2-4 days after plaque formation * Neutrophil infiltration * Increased GCF * No Gingivitis Stage 2: * Early Lesion * 4-7 days * T lymphocyte infiltration * increased collagen loss * BOP * Clinical Signs of Gingivitis: Redness, bleeding, edema Stage 3: Chronic Gingivitis/reversible * Established lesion: 14-21 days * B lymphocyte (B Cells) infiltration including mature plasma cells * collagen loss * clinical changes in color, contour, and consistency Stage 4: Not reversible * Advanced lesion * transition to irreversible damage of periodontitis

Question 39

Macrophages

Answer 39

Antigen-presenting cells (APCs) * monocytes * dendritic cells Regulate immune response by releasing cytokines * ex: IL-8

Question 40

Mast Cells

Answer 40

Vascular Permeability & dilation

Question 41

Lymphocytes

Answer 41

B cells * become plasma cells--> make antibodies T Helper cells (CD4) * communication T Cytotoxic Cells (CD8) * kill intracellular antigens NK Cells: * T cells * recognize and kill tumor and viral infected cells

Question 42

MMPs

Answer 42

MMPs * matrix metalloproteinase * destroy collagen * Protain-ase=eats proteins

Question 43

Anti-inflammatory Mediators

Answer 43

IL-4 IL-10 TIMPs