Caries 2 Flashcards
Fill in gaps:
Demineralisation is occurring beneath the enamel surface and spreads towards enamel surface and towards the ?. This occurs as the biofilm sitting on the tooth surface is producing acid, reducing pH to below ? and causing dissociation of the ? within the enamel.
The overlying enamel, the dissociated ions increase in concentration and reprecipitate initially so you get some remineralisation occurring in the early stages of the ? development. Unusual appearance of the surface being remineralised and the subsurface becoming demineralised. They demineralisation` leads to ? in the enamel.
EDJ
5.5
mineral
lesions
porosity
What happens when enamel crystals come in contact with acid?
The prisms and boundaries suffer acid demineralisation.
The prism boundaries (where the crystals change orientation) are where the organic component of the enamel concentrates.
What clinical observations can be seen with acid affecting enamel?
Frosty white appearance of the enamel, chalky and softened, increased porosity.
Roughened surface
Brown spot lesion will form over time.
What does the 10% non-collagenous proteins do in dentine?
Matrix and mineral production
Where do to dental tubules run from in dentine?
Dental tubules run from the enamel dentine junction to the pulp border.
What biochemical affects does acid have on dentine?
Dentine is composed of mineral tissues, collagenous matrix and tubules.
Bacteria penetrates via the tubules and branches.
Proteolysis - collagen breakdown via host and bacterial enzymes.
What can be seen clinically on dentine affected by acid?
- brown colour due to protein&carbohydrate in a acid environment
- hardness as demineralisation causes softening
- dentine-pulp complex reaction (translucent dentine,, reparative dentine)
What shape does a lesion demineralise into?
An inverted cone shape until it reaches the EDJ where the lesion then spreads along the EDJ due to the porosity of increased tubules.
Tertiary dentine can form.
Why is translucent dentine particularly hard?
Why does it form?
It is hypermineralised.
Forms as a defence reaction to caries process.
What are each of these as clinically detectable lesions? D1 D2 D3 D4
D1 - white spot
D2 - gets categorised into enamel
D3 - enamel spread to dentine
D4 - lesions in the pulp
What system is used to look at the lesions?
Explain the numbering
ICDAS (international caries detection and assessment)
0 - healthy tooth, no demineralisation when tooth is dry
1 - wet tooth looks normal, start seeing frosting when dry, enamel demineralisation has occurred limited to outer 50% of enamel
2 - wet tooth shows discolouration but no clinical caries detectable
3 - breakdown to some degree
4 - lots of breakdown, obvious lesion
1- outer half of enamel 2- inner half of enamel 3 - outer third of dentine 4 - middle third of dentine 5 - inner third of dentine
What are the features of a D1 and D2 lesion?
Histology:
- early subsurface
- early porosity
- some bacterial penetration
Clinical:
- white frosty lesion
- chalky rough surface
- brown spot lesion
Symptoms:
- minimal
- slight reaction to hot and cold at the EDJ
Treatment:
- monitor
- fluoride
What are the features of a D3 lesion?
Histology:
- enamel demineralisation
- increased porosity
- bacterial penetration
- tubular destruction
- translucent dentine
- tertiary dentine
Signs:
- open or closed
- discolouration
Symptoms:
- reversible pulpitis
Treatment: (depends on how open or closed lesion is)
- monitor fluoride
- minimal cavity prep
- sealed MI restoration
What are the features of a D4 lesion?
Histology:
- gross demineralisation
- tubular destruction with pulp exposure
Signs:
- cavitation
- gross discolouration
- visible necrotic pulp
Symptoms:
- chronic irreversible pulpitis
- loss of function
Treatment:
- pulp capping
- MI sealed and layered restorations
- pulp extirpation and root canal treatment
