PDL Flashcards
PDL is also known as…
periodontal membrane or suspensory attatchment
Where is PDL located
between the alveolar bone and the cementum
how thick is the PDL
.15 - .38 mm
What makes up the PDL(8)
-collagen *
-fibroblasts *(most prolific)
-Epithelial Cells(HERS)
-Osteoclasts and Osteoblasts
-Macrophages
-Extracellular material
-Cementum(cementicles)
-blood vessels & nerves
Functions of PDL
Supportive: stretch when we clench our teeth , most important function
Formative: helps cementum during it s growth
Sensory: has abundant nerve receptors ; can sense pain and proprioception
Nutritive: Very vascular which provides a lot of nutrients
Resorptive: resorptive function allows us to move teeth orthodontically; the fibers resorb and then grow again
Maintainance: constantly building up and breaking down; constantly being replaced ; this is essential to prevent pocketing
What are sharpeys fibers
Sharpeys fibers attatches the PDL to the cementum
What are the two principle fiber groups?
-Gingival Fibers
-Dentoalveolar Fibers
Which fibers are included in the Gingival Fibers Group
-Free Gingival Fibers
-Attached Gingival Fibers
-Circular/Circumferential Fibers
-Transseptal Fibers
Which fibers are included in the Dentoalveolar Fibers Group
-Alveolar Crest Fibers
-Horizontal Fibers
-Oblique Fibers
-Apical Fibers
-Interradicular Fibers
Free Gingival Fibers
Location
Function
-go from the cementum in the cervical area to the free gingiva
-support gingiva and keep tooth in place
Attached Gingival Fibers
Location
Function
-go from alveolar crest into attached gingiva
-support gingiva and keep tooth in place
Circumferential Fibers
Location
Function
-continuous around the neck of the tooth
-helps support the tooth and keep it in position
Transseptal Fibers
Location
Function
-cervical region of each crown and connects to the same area in adjacent tooth
-keep teeth together and prevent side to side movement
Alveolar Crest Fibers
Location
Function
- go from the crest of alveolar bone to the cervical area of the root into the gingival CT
-support teeth and resist traumatic forces & up and down forces
Horizontal Fibers
Location
Function
-found in the middle of the root and goes to alveolar bone
-support teeth and resist side to side movement
Oblique Fibers*
Location
Function
*these fibers are the MOST NUMEROUS
-they extend in an oblique fashion from just above the apical 3rd to the alveolar bone
-support tooth , resists traumatic forces, up & down movement and rotational forces
Apical Fibers
Location
Function
-found at the apex and goes to the fundic alveolar bone
-support tooth and resist up & down forces
Interradicular Fibers
Location
Function
-found between roots of multi-rooted teeth and go to the alveolar bone
-resists up & down and side to side forces and supports teeth
What are interstitial spaces
-space between collagen bundles
-Oxytalon fibers, vessels, nerves & lymphatics (interlacing fibers) are located here
What are oxytalan fibers
elastic-like short fibers that lay beside and interlace collegen fibers that help hold the blood vessels in place
Where does the PDL receive its nourishment
Superior Alveolar Artery and Inferior Alveolar Artery
Where do the vessels that supply the PDL enter
-fundus of the alveolus
-sides of the alveolus from bone marrow spaces
-deeper branches of gingival blood vessels that pass over alveolar crest
The PDLs suspensory apparatus helps protect it by…
detecting pressure
the nerve trunk which is larger in the center of the tooths long axis branches and sends fibers to the …
bone and gingiva
In the area of compression there will be —- activity
osetoclastic
in the area of force there will be — activity
osteoblastic
What happens to the PDL with aging
-scalloping or wavy in appearance
-cell number and cell activity decreases
-if a tooth is lost the antagonists’ fibers will become loose and wavy
When the PDL is thickened this is a sign of…
infection pushing the tooth out of the socket
