CONFIRMED OSPE TOPICS Flashcards
list bacterial virulence factors
bacterial virulence factors = enable bacterial invasion and colonisation of periodontium
**bacteria characteristics
**- pili/fimbriae = adhesion/invasion
- capsule = protection against phagocytosis
- peptides = induces inflammation
**produced produced by bacteria **
- exotoxins = damage host immune cells
- enzymes = damage host proteins + acquire nutrients
OUTLINE THE TYPES OF DENTINE
primary
secondary
tertiary
describe primary dentine
- formed BEFORE to eruption - deposited at DEJ
- has incremental lines
- outer layer = mantle dentine [150um thick]
outer layer is divided into: [from outside to in]
- circumpulpal dentine
- globular dentine
- peritubular/intratubular dentine
- intERtubular dentine
describe secondary dentine
- formed AFTER completion of root formation and thoroughout tooth ageing process
- aka circumpulpal dentine
- scatters more slowly than primary
- causes canals to be smaller w age [deposition = decreased pulp chamber size]- - forms at roof and floor of roof chamber
describe tertiary dentine
forms if dentine experiences
- mechanical trauma
- irritation
- exposed hypersens dentin
- carious dentine
- traumatic cavity prep
reactionary
- forms in response to insult, damange sustained but **existing cells recover **
- formed by existing odontoblasts
reparative
- forms in response to insult, damage sustained –> original odontoblasts destroyed –> induces odontoblast precursors to differentiate and produce calcified tissue
describe general dentin properties
- forms BULK of tooth
- covered by enamel in the crown and cementum in the root
- consist of large number of small parallel tubules in mineralised collagen matrix [contains odontoblastic processes and dentinal fluids]
- harder than bone and cementum but softer than enamel
- by weight [inorganic 70%, organic 20%, water 10%]
outline the layers of dentine
crown
- mantle dentine
- interglobular dentin
- circumpulpal dentine [bulk] - covers pulpal space
[circumpulpal further div into:
- globular dentine
- peritubular/intratubular dentine
- intERtubular dentine
root
- hyaline layer
- granular layer of Tomes
- circumpulpal dentin [bulk]
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briefly describe mantle dentine
deposited FIRST under DEJ in 150um wide band - mineralised by matrix vesicles
fibres perpendicular to DEJ
secreted by immature odontoblasts
briefly describe circumpulpal dentine
layer of dentine around outer pulpal wall - makes bulk of dentin in both crown + root
formed and matured after mantle dentine
briefly describe inter/globular dentine
between mantle and circumpulpal
beneath mantle dentine [crown] and grnular layer of tomes [root]
calcified following formation of matrix
becomes larger –> fuses as dentine develops - interglobular spaces present
briefly describe peritubular and intertubular dentin
peritubular dentin
- immediately surrounds dentinal tubule
- higher mineral content and LACKS collagenous matrix [more calcified and mineralised - less organic structure]
intertubular
- forms bulk of dentine around dentinal tubules of crown and root
- less mineralised
describe PDL
fibrous collagen CT between alveolar process and cementum
occupies periodontal space
contains
- fibroblasts, osteoblasts, cementoblasts
- blood cells
ground substance - 70% water w glycoproteins and proteoglycans
highly vasculuar + nerves
provides attachment of cementum to surrounding alveolar bone keeping the teeth resting in its socket - - acts as suspensory ligaments of teeth
- major func = permits tooth to withstand force of mastication
outline PDL organisation
group according to location
- gingival group
- around necks of tooth - support gingiva
- 1 alveologongival [free]
- 2 dentogingival [attached]
- 3 circular / circumferential fibres
- 4 dentalperiosteal - transeptal
- in between teeth
- cementum to cementum over alveolar crest
[func = resist rotational forces - holds teeth in interproximal contact] - dentoalveolar
- cementum to bone
- contains
alveolar crest group = resist tilting/rotation
horizontal group = resist tilting M/D/L/F / rotation
oblique group = resist inwards pushing and rotation
apical group = resist outward pull and rotation
interradicular group
outline oral mucosa classifications
lining mucosa
- found in areas which dont func in mastication
- softer surface texture, moist surface, ability to stretch/compress, cushions underlying structures
- eg soft palate, central surface of tongue, floor of mouth, alveolar mucosa, labial and bicca; mucosa
masticatory mucosa
- comes into primary contact w food during mastication
- covers immobile structures and firmly bound - well adapted to withstanding abrasion
- eg hard palate, free + attached gingiva
specialised mucosa
- assists in mastication + taste buds
lingual papillae
- foliate papillae - not well devel in humans
- filiform - ant 2/3 tongue
- fungiform - ant 2/3 tongue
- circumvalate - adjc//ant to terminalis sulcus
briefly describe the lamina propria
CT supporting oral epithelium
high vascularised capillary networks/loops
composed of TWO layers
1. papillary layer
- most superficial
- associated w rete ridges, collagen fibres and capillary loops
- reticular layer
- deeper layer
- dense conc of collagen arranged into bundles lying parallel to surface plane
list the layers of lining mucosa from superficial to deep
- superficial layer [flattened cells]
- intermediate layer
- basal layer [cuboidal above lamina propria]
- lamina propria [capillary loops + parallel bundles]
- submucosa
- muscle
list the layers of masticatory mucosa from superficial to deep
- keratin layer
- granular layer
- prockle layer
- basal layer [cuboidal cells above lamina propria]
- lamina propria [capillary loops + parallel bundles]
- minimal or absent submucosa
- bone
describe what happens in the pre eruptive phase
- movements related to tooth eruption occur PRIOR to crown formation [ant tooth germs move M and molars move D]
- movements facilitated by
bodily movment - mediated by bone remodelling of crypts - incl early initiation - finishes @ early root formation
describe what happens in the pre eruptive phase
- elongation/ development of root needs SPACE –> given by occlusal/incisal eruption
[allows root, dentin, cementum development]
axial/occlusal movement eruption pathway
- tissue removed by macrophages
- bone remodelled via osteoclasts
REE proliferates upwards, oral ectoderm proliferates downwards = cells fuse creating JE which attaches to developmental cuticle via hemidesmosomes
crown tip penetrates oral mucosa, causing stretching and thinning of mucosa = developmental cuticle remains
occlusal movement cont. until contact w opposing crown
more exposed crown shifts oral epithelium to cervical region
fine trabeculae form in fundic region, bone becomes denser when func occ reached
deciduous roots resorped to make way for permanent eruption sequence
debatable mechanisms
1. hammock ligamant theory [fibrous tx band at apex = root pushes against this]
2. bone remodelling theory
3. ligament traction theory
4. vasculuar pressure theory
describe what happens in the post eruptive/ func phase
occurs when teeth reach func occ and continues as long as teeth are present
during process of root completion - alveolar height increases
fundic alveolar plates resorp to accomodate formation of root tip apex
marked changes
- ^ bone mineral density
- ^ density and orientation in PDL
THREE catergories
1. accomodation of growth
- occurs 14-18, completes towards 20yo
- socket readjustments from new bone deposition
- compensation of occlusal wear
- continued cementum deposition [only after teeth move] - accomodation for interproximal wear
- at contact points
- M drifting accomodtes for interproximal wear
- up to 7mm in mandible
distinguish between major and minor glands
major
- carry secretion through longer main duct into oral cavity
- parotid, submandibular, sublingual
- inactive during sleep
minor
- empty sec. via short ducts
- separated small glands throughout mouth
- active all the time
- mostly mucous w/ some serous influence
BOTH = compose of epithelium + CT
epithelium = lines duct system and produces saliva
CT = surrounds epithelium - protecting tissue + supporting gland
distinguish between the two secretory cell types
serous = high protein low carbohydrate
mucous= low protein high carbohydrate
- most minor salivary glands –> mostly mucous cells
outline the structure of salivary glands
stroma [supportive CT]
- septa [carries blood and nerve –> parenchyme]
- blood vessels and nerves
- ducts
- lobules
parenchyma [glandular secretory tissue]
- accini [func unit of salivary gland]
- duct system
describe the parenchymal structure of major salivary glands
parotid
- largest gland
- 25% of total salivary volume
- parotid duct/Stenson’s duct opens –> parotid papilla
- mainly serous
submandibular
- 2nd largest
- 60-65% total salivary vol
- travels through Wharton’s duct –>opens into oral cavity –> sublingual caruncle
- both serous and mucous products
sublingual
- smallest
- 10% total salivary vol
- travels through Bartholin’s duct –> open into oral cavity –> sublingual caruncle
- mainly mucous