Quiz 2

Question 1

What are some of the host-derived enzymes of gingival crevicular fluid?

Answer 1

The phosphatases (which are also bacteria-derived), aspartate aminotransferase, and elastase. Elastase comes from PMN’s so high levels usually means a disease.

Question 2

What are some of the bacteria-derived enzymes of gingival crevicular fluid?

Answer 2

The phosphatases, collagenase, hyaluronidase, and the phospholipases

Question 3

What are the three non-enzymatic components of gingival crevicular fluid?

Answer 3

1. Cellular components
2. Electrolytes
3. Organic components

Question 4

What are the three things that make up the cellular components of GCF?

Answer 4

1. Bacteria
2. Desquamated epithelial cells
3. Leukocytes (PMN’s, lymphocytes) which migrate through the sulcular epithelium.

Question 5

Which type of electrolytes have been found in GCF?

Answer 5

Sodium, potassium, calcium, magnesium, and fluoride. With inflammation there is a positive correlation of Ca and Na concentrations and the Na/ K ratio.

Question 6

What are the two main organic components found in GCF?

Answer 6

Glucose Hexosamine and Hexuronic Acid are two of the components found in gingival fluid. Glucose concentration in gingival fluid is 3-4 times greater than that found in serum. This is the result of metabolic activity of adjacent tissues and the local microbial flora.

Question 7

What are the four main metabolic end products found in GCF?

Answer 7

1. Lactic Acid
2. Urea
3. Hydroxyproline
4. Endotoxins (lipopolysaccharides)

Question 8

What are the potent local mediators of inflammation that are produced by a variety of cells in gingival fluid?

Answer 8

Cytokines. Specifically, Interleukin 1, 6, 8, and Tumor Necrosis Factor. Both IL-1α and IL-1β have pro-inflammatory effects and depending on a variety of factors can stimulate either bone resorption or formation.

Question 9

What is Prostaglandin E2 and what is it’s association with Gingival Crevicular Fluid?

Answer 9

PGE2 is a product of the cyclooxygenase pathway. It was first identified in 1974. Elevated levels of PGE2 in GCF were found in patients with periodontitis compared to patients with gingivitis. PGE2 levels are 3x’s higher in patients with LAP compared to adult periodontitis.

Question 10

What are the normal clinical characteristics of attached gingiva?

Answer 10

The color is pale or coral pink.
May be pigmented and darker with different races.
It allows gingival tissue to withstand mechanical forces created during chewing, speaking, and toothbrushing.
Prevents free gingiva from being pulled away from tooth when tension is applied to alveolar mucosa.
Stippling looks like an orange peel and it is on the facial side and is made up of rete pegs and epithelial projections.

Question 11

What is the average width in millimeters of facial attached gingiva of the maxillary incisors and of the premolars?

Answer 11

Incisors - 3.5 to 4.4 mm

Premolars - 1.9 mm

Question 12

What is the average width in millimeters of facial attached gingiva of the mandibular incisors and of the premolars?

Answer 12

Incisors - 3.3 to 3.9 mm
Premolars - 1.8 mm
The mandibular premolars and incisors are usually lost first because we are starting with less attached gingiva from the get-go when compared to the maxillary teeth

Question 13

What are the three factors that largely determine the shape of gingiva?

Answer 13

1. Relationship to teeth (crowns)
2. Genetics
3. State of health

Question 14

What is the papilla and contact point rule:

Answer 14

If you have less than 5 mm between the contact point and alveolar bone, you will have interdental papilla in there 100% of the time. If it is 6 mm or greater, you will have it 56% of the time. You may get black triangle, which is healthy but not pretty.

Question 15

What is the Col?

Answer 15

It connects the facial and lingual papillae.
1. Depression between facial and lingual interdental gingiva.
2. Center is not keratinized.
3. More susceptible to disease.
When you start getting recession, Col will become keratinized and convex instead of concave.

Question 16

Where is the junctional epithelium found?

Answer 16

It is found on the enamel of the tooth, in the gingival sulcus. Hemidesmosomes are what help the epithelium attach to the tooth.

Question 17

What are some characteristics of junctional epithelium?

Answer 17

1. Continuous with sulcular epithelium.
2. Completely encircles the tooth.
3. On enamel and apically extends onto CEJ
4. Only place in the body where you have two layers of basal lamina
5. stratified squamous, non-keratinized cell length of 1 to 2 mm
6. The internal basal lamina attaches to enamel and the external basal lamina attaches to connective tissue
7. The JE is reinforced by collagenous fibers in the marginal gingiva and is a functional unit known as dentino- gingival unit
8. Widest at the sulcular epithelium (15 to 30 cells, and narrows to a few cells at the apical end (1-3 cells)
9. Has attachment role and protective role
   Permeability allows GCF and defense cells to pass across to protect underlying tissues from disease processes (periodontal disease) Helps maintain integrity of tooth / periodontium structure.
10. GCF contains g globulins and polymorphonucleocytes (PNMs) giving it immunological / phagocytic properties to combat disease processes. Such molecules pass readily across JE to underlying tissues. JE (& GCF) good indicator for severity of periodontal disease – may contain neutrophils & other inflammatory cells indicating disease – & state of health of periodontium
    

Question 18

Where is junctional epithelium derived from?

Answer 18

It is derived from the Reduced Enamel Epithelium (REE). REE replaced once tooth erupts – REE covering crown lost rapidly replaced by squamous epithelial cells. Transformed REE & oral epithelium form dentinogingival junction and junctional epithelium. Final conversion of REE to JE may not occur until 3-4 years post eruption

Question 19

10 more characteristics of junctional epithelium:

Answer 19

1. The length of JE varies according to stage of eruption
2. When the tooth first erupts, most of the enamel is covered by the JE
3. When tooth reaches occlusal plane, about 1/4th of the enamel is covered by JE
4. Eventually the JE lies close to the CE junction
5. Older patients with root exposure (passive eruption or disease) JE proliferates apically - firm attachment with cementum
6. The Lamina propria of gingiva is good vasculature and source of nutrient to JE and source of GCF
7. JE is permeable & tissue fluid and cells pass into GCF
8. Most of the fluid in a healthy sulcus will be coming through the junctional eipthelium and not the sulcular wall. But once you get disease and a break in the sulcular wall, then more and more come through the sulcular wall.
9. Turnover of JE is very rapid. Epithelial cells migrate coronally & shed into oral cavity via gingival crevice
10. Rate of turnover dependent on demands placed on tissue. Directly related to degree of inflammation.

Question 20

What is the lamina propria and what are its two layers?

Answer 20

It is the dense connective tissue beneath the masticatory mucosa.

1. Papillary layer: which forms finger- like extensions in the depressions delineated by the rete ridges
2. Reticular layer: that is located beneath the rete ridges.

Question 21

What are the three major gingival fiber groups

Answer 21

1. Gingivodental
2. Circular
3. Transseptal

Question 22

What makes up gingival connective tissue?

Answer 22

Cells make up about 5% of gingival CT.
Fibers make up about 65% of gingival CT.
The remainder is proteoglycans, glycoproteins, and connective tissue ground substance.

Question 23

Out of the fibers in the gingival connective tissue, what are the fibrillar elements in this tissue?

Answer 23

It is about 60% collagen, Type I and Type III. Elastic fibers, oxytalan fibers, and ground substance as well. Type IV is the most common in the basement membrane.

Question 24

What is the term that encompasses the periodontal ligament, the cementum, and the alveolar bone all together?

Answer 24

The attachment apparatus

Question 25

What are the 5 functions of the periodontal ligament?

Answer 25

1. Suspend and maintain tooth in socket
2. Provides pressure and pain sensory feeling to tooth
3. Provides nutrients to cementum and bone
4. Builds and maintains cementum and alveolar bone of tooth socket
5. Remodels alveolar bone in response to pressure

Question 26

What are the main fibers of the periodontal ligament?

Answer 26

Collagen fibers of the PDL
- principle fibers
- intermediate plexus fibers
- sharpey's fibers
- indifferent fiber plexus
Elastic fibers
- oxytalan fibers

Question 27

How thick is the average periodontal ligament?

Answer 27

Between 0.1 and 0.25 mm.
Widest during heavy occlusion thinner in nonfunctional teeth
The diameter is 2-3 μm at eruption and is doubled
when in fully functional teeth.
**Also important to note that fiber bundles are larger and less numerous on the bone surface than on the cemental surface. This would be helpful to know if we were asked to look at a histology picture or a radiograph and determine which side is which

Question 28

What is the surface area for a socket wall of a tooth that is both single-rooted and multi-rooted?

Answer 28

150-275 sq mm single root
450 sq mm multi-rooted
Number of periodontal ligaments?
• 2000/sq mm in non-functional • 28,000 in functional