cementum Flashcards
what is cementum?
a hard calcified layer of tissue that covers the root of a tooth
in what ways is cementum’s structure similar to bone?
- it has a matrix containing predominantly collagen
- it has a lamellar arrangement
what do cementocytes do?
- maintain cementum
what is the function of cementum?
- provides attachment for periodontal fibres
- connects tooth to bone
- cementum is avascular
what are the two types of cementum?
- cellular
-acellular
what is acellular cementum?
- contains NO cells
- adjacent to dentine
- primary cementum (formed first)
what is cellular cementum?
- contains cells- cementocytes
- present in apical parts of the root and in furcations
- secondary cementum (formed after acellular cementum)
what is a tooth furcation?
region in-between roots of tooth
what is acellular extrinsic fibre cementum?
- collagen fibres from the periodontal ligament called Sharpey’s fibres
- equivalent to primary acellular cementum
- present on cervical 2/3 of roots
what is cellular intrinsic fibre cementum?
- intrinsic collagen fibres parallel to surface
- equivalent to secondary cellular cementum
- no role in tooth attachment
- may represent a transitional form
what are the fibres connecting acellular cementum and bone?
periodontal fibres (Sharpey’s fibres)
how do cementocyes appear on staining?
dark blobs
how could acellular and cellular cementum appear if found in the same region?
in layers
how does the cementum remodel?
cementoblasts become embedded in the ECM and become cementocytes
what is the interaction between cementum and enamel?
- can overlap
- can align
- if a gap is left, dentine is exposed causing problems and discomfort to patient
