19 AUG 2020 · BONE
ï‚· PDL attachment is to : alv. Bone proper or called bundle bone
ï‚· The crest of INTERDENTAL BONE is said to be parallel to the marginal gingiva
ï‚· Or you could also say it id parallel to the line drawn from the CEJ of adjacent teeth.
ï‚· Now if the position of CEJ of the neighboring tooth is variable, then the bone will be angulated towards the line.***
PERIODONTAL LIGAMENT
ï‚· Cells
o Fibroblast
o Osteoblast
o Cementoblast
o Cell rest of malassez
Lateral periodontal cyst from rest of serres ,while apical periodontal cyst from rest of malassez.
ï‚· Fibres
o Collagen
o Elastic fibres
ï‚· Cementoblasts present in pdl
ï‚· Cell rest of malassez seen commonly at apex
FIBRES OF PDL
ï‚· COLLAGEN 1,3,7
ï‚· Most dental tissue type I collagen fibres
o Eg: pdl,alveolar bone, cementum, gingiva, dentin
o They are most abundant
ï‚· Anchoring fibres are type 7, seen in pdl
ï‚· Type 3 also seen in pdl
Ageing OF PDL
ï‚· Elastic fibres increase and cells decreases
ï‚· Function of pdl
ï‚· Formative, nutritive, anchorage, cushioning (type 7)