originate from cementum pass beyond tip of alveolar bone to insert into periostium of alevolar bone

Organic portion of cementum composed of

Proteins - Ground substance - Water - Non-collagenous proteins Produced by cementoblasts or fibroblasts

provides a continually adapting structure for the support of the teeth during functions.

Periodontium forms a specialized fibrous joint called

(secondary cementum)

From cementum goes downward Attached to the tip of alveolar bone neck region

2 kinds of PDL fibers

cementum Collagen fibers of Organic matrix is derived form 2 sources:

intercellular substances of pdl

not formed by cementoblast, but he rtwigs epithelial rooth sheath

light yellow and slightly lighter in color than dentin. avascular highest fluoride content of all mineralized tissues

sends inductive signal to ectomesen-chymal pulp cells to secrete predentin by differentiating into odontoblasts. Root dentin forms.

formative cells of cementum in the surface of cementum

cementum 50 to 200 um (can exceed > 600um)

most common reasons for root caries occurrence is

Small gap between cementum and enamel

apical migration of marginal gingiva

Cementum just meets enamel

inorganic or mineral content hyddroxyapatite crystals cementum percentage

consisting of free gingiva and alveolar mucosa

thin layer of hard dental tissue covering the anatomic roots of teeth formed by cells known as cementoblasts, which develop from undifferentiated mesen-chymal cells in the connective tissue of the dental follicle.

one component of PDL you dont see in other structure

Hyaline layer of Hopewell-Smith also known as

• Covers 2/3rds of root corresponding with the distribution of primary acellular cementum • Principal tissue of attachment • Function in anchoring of tooth • Fibers are well mineralized

derived from PDL. same direction of the PDL principal fibers i.e. perpendicular or oblique to the root surface

collagenous principal fibers of the periodontal ligament embedded in both cementum and alveolar bone to attach the tooth to alveolus.

epithelial cells of pdl

extrinsic fibers coming from

Cementum that normally fills the resorption lacunae • Contains cementoblasts and collagen fbers produced by cementoblasts.

only type of fiber attached from one tooth to another tooth in the gingival region attached to two teeth

bacterial organism that cause dental caries in ENAMEL

incremental lines of salter are

formed continuously throughout life because as the superficial layer of cementum ages, a new layer of cementum is deposited to keep the attachment intact.

uncalcified matrix of cementum lined by cementoblast is called

Calcified ovoid or round nodule found in the PDL • Single or multiple near the cemental surface • Free in ligament; attached or embedded in cementum • Aging and at sites of trauma

attached to the cementum to the lamina propria

connective tissue structure with its stratified squamous epith.

dull surface more permeable than other dental tissues softness and the thinness at the cervical portion

attaches the teeth to the maxilla and mandible.

Embryonically, cells are derived from the dental sac or follicle (from ectomesenchyme)

cementum, periodontal ligament and alveolar process

Periodontium DIVIDED INTO 2 based on function

PDL help attached gingiva tp the tooth

Cementum overlaps enamel

thickest in the apex and inter-radicular areas of multirooted teeth

one end attached to the bone and one to cementum

It is a hard avascular connective tissue that covers the roots of teeth

-Thin of compact bone with many openings. -part of the maxilla and mandible - Supports the sockets

is a hard avascular connective tissue that covers the roots of teeth

living tissue that does not incorporate cells into its structure and usually predominates on the coronal half of the root

3 classification of cementum

FORMATION AND PROGRESSION OF DENTAL CARIES increased risk for root caries among individuals with 3 reasons

Represents all the cementum that is formed after the tooth comes in occlusion. • Continuously forms all through out life.

Main and most numerous alveolodental ligament Attachment on the bone is higher than to other tooth Mana support during mastication

cementum They are hypermineralized area with less collagen fibers and more ground substance

Cells of cementum that are embedded in the calcified matrix within cementum doesnt have the capbility to form cementum

cells in the cementum

organic matter + water percentage cementum collagen polysaccharides

4 tissues of periodontium

It contains cellular components and collagen fibers derived from cementoblasts and PDL

contains cementoblasts (inside the lacuna) and is often formed on the apical half.

cementoblast came from

UMC from PDL may Differentiate into

4 signs of aging cementum

roles of cementum 4

derived from cementoblasts. Run parallel to the root surface and at right angles to the extrinsic fibers

(primary cementum)

inner wall of bony socket. consists of thin lamella of bone that surround the root of the tooth and gives attachment to Sharpey's Fibers.

Demineralisation is approximately twice as rapid on root surfaces as on enamel

Which surrounds the alveolar bone proper and support the socket.

this ligament is a complex, soft CT containing numerous cell, blood vessel, nerve fibers and ground substance.

the tooth root is attached to the alveolus (bony socket) by periodontal ligament.

process of forming cementum happends during root development stage of tooth

Represents cementum that is formed before the tooth is established in occlusiom

Cementum that is found at the apical third of the root, apices and furcation areas of multi-rooted teeth.

When thin layer of cementoid is formed, mineral salts from the tissue fluid of PDL is deposited as HA crystals along the collagen fibers.

bacterial organism that cause dental caries in ROOT

Fan shape orientation of fibers at the tip of the root radiate on the apical region of root

2 mineralized CT of Periodontium

The area where both extrinsic and intrinsic fibers is called

cementocytes shrink and stay in

Perpendicular or at right angle of the long axis of tooth

• First cementum • Primary cementum • Acellular • Before PDL forms • Cementoblasts • 15-20um

soft, progressive lesion that is found anywhere on the root surface that has lost its connective tissue attachment and is exposed to the environment.

bacterial organism that cause dental caries in DENTIN

-hard tissue with a calcified intercellular substance covering the anatomical roots of Teeth

(Extension of the inner and outer dental Epithelium) forms and grows apically

occurs at or apical to the CEJ.

5 FUNCTIONS OF PDL

fibers that goes around the tooth on the cervical region forms a band help bind gingiva to prevent from getting freeid out of tooth

resorptive cells of pdl

cervical enamel • Forms the coronal cementum

originate from the tip of alveolar bone to the lamina propria

2 steps in forming cementum

Cementum is more resistant to resorption: Important in permitting orthodontic tooth movement

cementum 10 to 15 um in the

Located in cervical half of the root and constitutes the bulk of cementum

Connective tissue fibers from the PDL are embedded in the cementum and serve to attach tooth to surrounding bone (Bone bundle) arwe called

Soft, specialized connective tissue situated between cementum and the alveolar bone lining the socket.