Oral biology, enamel, dentine and bonding: oral biology lecture 1 Flashcards
oral biology lecture 1
what can over drying of the etched dentine result in
collapse of the collagen layer
this results in reduced bond strength
it is essential to keep it slightly wet, also called WET BONDING
dentine is classified as peritubular and intertubular
how is inter-tubular represented
is the main body of dentin, located between zone of peritubular dentin. Type 1 collagen present in this region.
what is the name of the condition, where incremental lines appear on the surface of the tooth enamel, as a series of linear growth
perikymata
what does this image represent
hydroxyapatite
when would the Striae of Retzius appear as concentric circles
in a cross section
where would you find specialised connective tissue
dentine
what is the function of odontoblast found on the outer surface of the dental pulp
dentinogensis = formation of dentin
in the enamel prism where would you find tightly packed hydroxyapatite crystals
prism core
what can be determined from the striae of retzius
indicates enamel development, the lines indicate weekly growth.
which zone sits between the cell rich zone and the predentine
cell free zone of weil
dentine can be classified as primary, secondary and tertiary dentine
what is tertiary dentine
tertiary dentin is reactive dentine, this is localised formation of dentin on the pulp-dentin border, formed in reaction to trauma such as caries or restorative procedure.
which part of the tooth is comprised of 70% mineral and 20% organic collagen
dentine
which of the following mechnaisms of tertiary dentine responds the quickest to trauma
reparative - quickest
reactionary - slow formation
what is occuring at the body of lesion
- The largest part and centre of lesion
- 25-50% porosity
- Enamel is relatively translucent
- Striae of Retzius more obvious
- Corresponds to the radiographic appearance
what is occurin on the surface zone
- Relatively intact
- 30 um thick
- Highly mineralised – high fluorine content
- Porosity of 1-2%
- Forms/reforms during carious process
- Redeposition of mineral dissolved from deeper layers
(KHN 360-390)
which part of the tooth represents that figure
enamel
what is a white spot lesion
enamel caries
what is in dental tubules
depending on the location of the cross section of the dentinal tubules. different contents are found.
developmental dentine is broken down to 2 components mantle and circumpulpal dentine:
where is circumpulpal dentine located.
(Circumpulpal dentin, more mineralized dentin which makes up most of the dentin layer and is secreted after the mantle dentin by the odontoblasts)
in other words makes up most of the dentine
what is referred as a keyhole shape
enamel prism
what is aprismatic enamel
Aprismatic enamel is a thin surface layer of the tooth, thought to be solid without individual enamel rods or prisms.
- Surface of Aprismatic layer is 30um
- Apatite crystals parallel and tightly packed
- Essentially no sheath like enamel
- High fluoride content (more acid resistant)
- More difficult to achieve optimal etch
where is the most mineralised tissue located in a tooth.
enamel
dentine
cementum
bone
dentine can be classified as primary, secondary and tertiary dentine
what is secondary dentine
(it develops after root formation has been completed and representing the continuing but much slower, deposition of dentin by odontoblast. The ratio of mineral to organic material is the same as for primary dentin)
developmental dentine is broken down to 2 components mantle and circumpulpal dentine:
where is mantle dentine located.
(The outer layer closest to enamel is known as mantle dentin. … Mantle dentin is formed by newly differentiated odontoblasts and forms a layer consistently 15-20 micrometres (µm) wide)
