GINGIVA, CEMENTUM, PERIODONTAL LIGAMENT, AND ALVEOLAR BONE

3 Parts of the Gingiva

1. Gingival margin

2. Attached Gingiva

3. Alveolar mucosa

Characteristics of a Healthy Gingiva

Texture:

Color:

Contour:

Characteristics of a Healthy Gingiva

Texture: Stippled and Translucent in Appearance

Color: Pale pink or Coral pink

Contour: Scalloped and Knife-edged margin

• Located at the neck of the teeth

• The area that covers the neck of the tooth

Marginal Gingiva

On the Marginal Gingiva __% found on the cementoenamel junction(CEJ)

50%

These are calibrated instruments where you can find in color-coded sharp tip of the instrument

Periodontal Probe

should be the normal measurement of the pocket of the marginal gingiva/gingival sulcus

1-3mm

Unhealthy gums/diseased gums measurement during probing

4mm or more

Term for Contouring the alveolar bone

Alveolectomy

Term for cutting the gums

Gingivectomy

Term for contouring the gums

Gingivoplasty

• Area that has a shallow crevice around the tooth on one side then the other side is lined with epithelium of the free margin of the gingiva

• Formed when the tooth erupts into the oral cavity

Gingival Sulcus

● Continuous with the marginal gingiva/free marginal gingiva

● Firm, very resilient, tightly bounded by underlying alveolar periosteum

● From free marginal gingiva up to the level of alveolar mucosa

Attached gingiva

The width of the attached gingiva increases with?

• Age

• As the tooth Supraerupts

Covers the interdental/interproximal space of the two adjacent teeth

Interdental Papilla

• Valley-like depression or curvature that conforms to the shape of the interproximal tooth contact

• It is often absent when the teeth are not in contact

COL

● AKA Interdental space

● Areas found between adjacent tooth contact

Interproximal Space

3 microscopic structures that can be found from the free gingival margin up to the attached gingiva

● Oral Epithelium

● Sulcular Epithelium

● Junctional Epithelium

Covers the crest and the outer surface of the marginal gingiva and the surface of the attached gingiva

Oral Epithelium

Epithelium present on the Oral Epithelium:

Stratified squamous epithelium

the underlying connective tissue underneath the oral epithelium

Lamina Propia

Is a mucous membrane that lines the inside of the mouth

Oral Mucosa

It comprises the stratified squamous epithelium called oral epithelium and the underlying connective tissue called lamina propria

Oral Mucosa

Oral mucosa cells, being connected by what?

Desmosomes

The cells of the oral mucosa are interconnected with one another by desmosomes and may form what epithelium

parakeratinized stratified squamous epithelium.

Granular layer comprised of flattened cell called

keratohyaline granules

2 Layers of Oral Epithelium

1. Cuboidal and Columnal Cell layer

2. Spinous Polygonal layers

• AKA Pre-marginal Gingiva

• Lines the gingival sulcus

Sulcular Epithelium

Sulcular epithelium is a thin layer of ______________________that extends from the coronal limit of the junctional epithelium to the crest of the gingival margins

non-keratinized squamous epithelium

These are semi-permeable layer that the bacteria and irritants pass through the underlying tissues, these are pliable.

Sulcular Epithelium

Undergoes continues repair which moves the tooth in a coronal direction to the gingival sulcus (formed when the tooth erupts into the oral cavity).

Junctional Epithelium

Junctional Epithelium comprises of a collar-like band of non keratinized squamous epithelium which is ___thick and ____ long

• 3-20 cells thick

• 0.254 - 1.35 long

These are the junctional epithelium as well as the gingival fibers of the PDL

Dentogingival Unit.

Three Zones of Junctional Epithelium

1. Apical Zone

2. Middle Zone

3. Coronal Zone

Compromising the basal germinal cells

Apical Zone

Has predominantly adhesive properties

Middle Zone

• Which is quite permeable

• Bacteria can pass through

Coronal Zone

it is formed when the tooth erupts

Gingival Sulcus

What are the two types of gingival epithelium formed during gingival sulcular development?

1. Epithelium covering the outer surface of the marginal gingiva and attached gingiva

2. Gingival sulcular epithelium

Process of Gingival Sulcus Development:

1. After amelogenesis, the enamel is covered by the ____(_____________) which is attached to the tooth by the basal lamina

2. REE unites with the oral epithelium to form the __________ when the tooth erupts to the oral mucosa

3. During this time, the cell of REE is replaced by the ________________

Process of Gingival Sulcus Development:

1. After amelogenesis, the enamel is covered by the REE (reduced enamel epithelium) which is attached to the tooth by the basal lamina

2. REE unites with the oral epithelium to form the epithelial attachment when the tooth erupts to the oral mucosa

3. During this time, the cell of REE is replaced by the squamous epithelial cells.

Sometimes called the mirror that reflects the health of the individual

Oral Cavity

fluid that can be found in gingival sulcus

Gingival fluid(gingival crevicular fluid)

Gingival fluid has a presence of what?

Immunoglobulins

Immunoglobulins in GCF

IgG, IgA, and IgM

● Complement components of C3 and C4, in addition to plasma proteins albumin and fibrinogen

● Complement System:

C3

C4

plasma proteins

Albumin

Fibrinogen

Complement System that helps kill bacteria and viruses that cause diseases

C3

Complement System that Blood test to measure the activity of a certain protein

C4

● Compliments as a defense against bacteria and viruses

● Antibody that can pass/enter to the placenta of mother

IgG

● Mucosal immunity

● Found in the secretions (eyes, breast, saliva).

IgA

● Similar to IgG

● Has defensive action against bacteria and viruses ● Infectious diseases

IgM

Substances present in Gingival Fluid that are found in Gingival Sulcus “LUHH P, LALA!!ˮ

1. Lactic Acid

2. Urea

3. Hydroxyproline

4. Hydrogen Sulphide

5. Acid Phosphate

6. Lysozyme

7. Alkaline Phosphate

8. Lactic Dehydrogenase

9. Proteases

Functions of the Gingival Fluid

1. Lavage of material from the gingival sulcus

2. Antibacterial

3. Adhesive

Gingival Connective Tissue is also known as

Lamina Propia

Densely collagenous connective tissue of the gingiva

Gingival Connective Tissue

Gingival Connective Tissue contains prominent collagenous fibers called?

Gingival Fibers

Gingival connective tissue has 2 layers:

1. Papillary Layer

2. Reticular Layer

Subjacent to the epithelium consisting of papillary protections between the epithelial rete pegs

Papillary Layer

Continuous with the periosteum of alveolar bone

Reticular Layer

Functions of the Gingival Connective Tissue

1. Brace the marginal gingival firmly against the tooth

2. Provide rigidity necessary to withstand displacement of the gingival from the tooth surface during mastication

3. Unite the free marginal gingival with the cemental tooth surface and the adjacent attached gingiva

Prominent collagenous bundles found in gingival connective tissue

Gingival Fibers

Gingival Fibers are arranged into 3 principal groups:

1. Gingivodental Group

2. Circular Group

3. Trans-septal Group

● Embedded into cementum and is spread fan-like fashion into the periosteum in the buccal and lingual of the alveolar periosteum on the interdental gingiva and attached gingiva

Gingivodental Group

Only seen in marginal and interdental connective tissue; it encircles the tooth in a ring-like fashion

Circular Group

Horizontal bundles between the cementum of the approximating teeth into which they are embedded. Between two teeth by means of two teeth/cementum

Trans-septal group

Cells present in the Gingival Connective Tissue

1. Fibroblast

2. Microphages

3. Polymorphonuclear leukocytes

4. Lymphocytes

5. Plasma

These cells present in the Gingival Connective Tissue are embedded in a non-collagenous ground substance comprising:

1. Glycoproteins

2. Glycosaminoglycans

Gingival Vascular Supply

1. Supraperiosteal Arterioles

2. Vessels of the Periodontal Ligament

3. Arterioles emerging from the Crest of the Interdental Septa

Located along the facial and lingual alveolar bone surfaces, capillaries extend along the sulcular epithelium and between the epithelial rete pegs

Supraperiosteal Arterioles

Extend into the gingiva to anastomoses with capillaries in the sulcus area

Vessels of the Periodontal Ligament

Anastomose with capillaries of the periodontal ligament, gingival crevicular areas and vessels that run over the alveolar crest

Arterioles emerging from the Crest of the Interdental Septa

Connects vessel to vessel

Anastomose

Gums are innervated by

1. Labial, Buccal, and Lingual Nerves

2. Meisner-type nerve endings

● Touch receptors (add. only)

3. Krause-type nerve endings

● Temperature receptors (add. only)

specialized nerve endings that innervates the gingiva

Krause-type and Meisner-type

on Gingival Morphology color the Coral PInk signifies what?

Reflection of rich blood supply and degree of epithelial pigmentation and keratinization

Derived from the activity of the neural-crest derived melanocytes in the basal and spinous layers of the epithelium.

Melanin Pigmentation

On Melanin Pigmentation the pigment is synthesized by the intercellular premelanosomes or melanosomes containing ________

Tyrosinase

Contour of the gingiva depends on what?

○ Shape of the teeth.

○ Alignment of the teeth within the arch

○ Location and size of the proximal contact between adjacent teeth.

○ Dimensions of the facial and lingual gingival embrasures.

Early signs of gingivitis

-Stippling structure disappears and change into Smooth and shiny surface

Tooth Eruption:

○ The margin and sulcus are at the tip of the crown.

○ The level of free gingival margin migrates ______ along the tooth.

Cervically

The calcified mesenchymal tissue that covers the dentin surface of the tooth root.

Cementum

Color of Cementum

Light Yellow, slightly yellow than dentin

Contains the highest fluoride content of all the mineralized tissue.

Cementum

Functions of Cementum

1. Attachment / Support

2. Protection

3. Reparative

4. Formative

Chemical Component of Cementum Made up of:

• 45-50% Inorganic Material

-Hydroxyapatite

• 50-55% Organic Material

-Collagen

-Protein

-Polysaccharides

What is the fibrous collagen fibrils forming fibrous structure which belongs to the periodontal ligament?

Sharpey’s Fibers

What is the fibrous collagen fibrils forming fibrous structure which belongs to the periodontal ligament?

Sharpeyʼs Fiber

Hypercalcified lines within the tooth cementum that appear during the cementogenesis process

Incremental Lines Of Salter

Non Collagenous Or Ground Substances(PGP)

○ Proteoglycans

○ Glycoproteins

○ Phosphoproteins

Cells Associated with Cementum:

1. Cementoblast

2. Cementoclasts

3. Cementocytes

For cementum cell formation found lining the root surface

Cementoblasts

Cementum destroying cells

Cementoclasts

These are formed when cementoblast are being trapped in the lacuna within their own matrix and become mature cementum cells (aka secondary cementum)

Cementocytes

Classification Of Cementum:

1. According to Location

2. According to Cellularity

3. According to Presence of Collagen Fibrils in the Matrix

4. According to Origin of the Matrix Fibers - A combination of all

Classification of cementum According to Location:

1. Coronal Cementum

2. Radicular Cementum

○ Formed on the cervical portion of the crown by cementoblasts.

Coronal Cementum

○ Formed on the middle third of the root and at the apical third of the root

Radicular Cementum

Radicular Cementum Thickness

0.5-0.6mm

Classification of cementum According to Cellularity

1. Accellular Cementum(Primary Cementum)

2. Cellular Cementum(Secondary Cementum)

What are Acellular Cementum/Primary Cementum

Cementum that covers the ○ Covers the coronal part of the root.

Acellular Cementum Thickmess

20-50 micrometers