Periodontium Flashcards
what is the periodontium?
tissues surrounding and supporting the teeth
what does the periodontium do?
retain tooth in socket, resist masticatory loads, defensive barrier, protecting tissues against threats from the oral environment
what is the junctional epithelium
the physical barrier separating the body tissues from the oral environment
what does the cementum cover?
root dentine
what is the structure of cementum?
collagen matrix and lamellar arrangement
what does the cementum do?
provide attachment for some periodontal fibres
what are the two types of cementum?
cellular and acellular cementum
what is cementum laid down by?
cementocytes
describe acellular cementum
no cells within, usually adjacent to dentine, first formed (primary cementum)
describe cellular cementum
contains cementocytes, later formed (secondary cementum), present in apical part of root and in furcation regions
which cementum type is primary cementum
acellular cementum
which cementum type is secondary cementum
cellular cementum
which type of cementum has sharpey’s fibres?
acellular extrinsic fibre cementum
what does the alveolar bone do?
provides attachment for periodontal ligament fibres, supports the teeth
what does the periodontal ligament contain?
cells, extracellular matrix, fibres, nerves, blood vessels
what does the ground substance (matrix) of the PDL consists of?
hyaluronate GAGs, glycoproteins, proteoglycans
what does the ground substance behave as?
viscoelastic gel
what are the cells in the PDL?
fibroblasts, cementoblasts, osteoclasts and cementoclasts, defence cells, epithelial cells
what type of sensory nerves are in the PDL?
mechanoreceptors and nociceptors
what are the mechanoreceptors responsible for?
rapidly or slowly adapting, chewing control via proprioception
what are the nociceptors responsible for?
protective reflexes, inhibit jaw elevator motor neurons
what are the nervous systems in the PDL?
sensory and autonomic
what is the autonomic responsibility in the PDL?
blood vessels control - vasoconstriction
where does the PDL get the blood supply from?
inferior and superior alveolar arteries passing into the PDL, lingual and palatine arteries supplying gingivae
