Oral Biology Flashcards
What do the tissues surrounding the teeth do?
They maintain the tooth in socket.
They resist masticatory load.
They are a defensive barrier,
What is the junctional epithelium?
The junctional epithelium is the physical barrier separating the body tissues from the oral environment.
What are the two categories of periodontal disease?
- Diseases of gingiva alone
- Diseases of all periodontal tissues.
What does cementum cover?
Root dentine.
- Collagen matrix
- Lamellar arrangement
Acellular (extrinsic) cementum?
- no cells
- has sharpeys fibres
- first formed
- adjacent to dentine
- present on cervical 2/3 of root
Cellular (intrinsic) cementum?
- contains cementocytes
- later formed
- present in apical parts of roots and in furcation regions
- no sharpeys fibres
- NO ROLE IN TOOTH ATTACHMENT
- intrinsic collagen fibres parallel to surface
What type of cementum is most likely to have a success rate after periodontal treatment?
- acellular extrinsic fibre cementum as it contains sharpeys fibres- have the potential to regenerate.
What happens to the alveolar ridge when teeth are lost?
When teeth are lost, the alveolar process is resorbed, leaving a ‘residual ridge’.
What type of canals penetrate alveolar bone?
Volkmanns canals.
What does the periodontal ligament contain?
A connective tissue, containing: Cells Extracellular matrix Fibres Nerves Blood vessels.
What glycoproteins are in the periodontal ligament matrix?
Fibronectin.
What proteoglycans are in the periodontal ligament matrix?
- proteodermatan sulphate
- chondroitin/dermatan SO4 hybrid
What does viscoelastic gel mean?
Generate infrastructure in matrix that is viscoelastic- glue/gel, like a jelly wobbling. Remove pressure springs back- return to original shape. PD can change the chemical arrangement of the matrix, viscoelastic capacity is lost. PD- losing tissue and viscoelastic.
What cells are in the periodontal ligament?
Fibroblasts (generate and maintain infrastructure) Cementoblasts Osteoclasts & cementoclasts Epithelial cells Cell rests (or debris) of Malassez Defence cells.
What are the sensory and autonomic nerves in the periodontal ligament?
Sensory: Mechanoreceptors (A and Aδ fibres) Rapidly or slowly adapting Proprioception; chewing control Nociceptors (Aδ and C fibres) Protective reflexes; inhibit jaw elevator motor neurons
Autonomic (sympathetic):
blood vessels control - vasoconstriction.
What arteries supply the PDL?
Inferior and superior alveolar arteries pass into the periodontal ligament from the alveolar bone.
Lingual and palatine arteries supply the gingivae.