measurement of caries Flashcards
what is caries
imbalance in the process of dynamic demineralisation and remineralisation
what happens at a low ph
hydroxyapatite more soluble
ions diffuse out of enamel into plaque fluid
Ca, PO4 and hydroxyl ions dissolve and combine with H+ in the environment
therefore low saturation of plaque
where is remineralisation easier
at the surface rather than the body of the cavity
at low caries levels
there are most precavitated lesions e.g. white spot lesions
an identifiable lesion can remineralise
Assessing the effectiveness of prevention in an individual
fluoride varnish
fissure sealants
Assessing the effectiveness of prevention in a community
water fluoridtion
other community programs
why is it difficult to diagnose caries
mouth is dark wet and mobile with small opening
early changes subtle
- most difficult in lower caries levels
-more difficult in presses of fluoride as surface mineralised but not deeper
- back of mouth difficult to reach
- consequences of incorrect diagnosis are severe
methods to diagnose caries
visual examination tactile examination radiographs transillumination electrical technique lasers and other technology
what does visual examination require
good light dry and clean teeth mouth mirror magnification can use temporary separation if suspicious of proximal caries
tactile examination
useful for difficult to see surfaces
- blunt explorer passes gently over surface of tooth
- don’t create cavities otherwise they cannot reminalise
radiographs
useful for proximal, less occlusal
transilluminaton
demineralised tooth absorbs more light and appears darker
- can use mouth mirror on anterior teeth
- for posterior can use fibre optic transilluminatio
electrical techniques
sound enamel has high electrical resistance to direct current tor impedance with alternating current
- technique sensitive, impacted by saliva, higher temperatures changes electrical conductnacne
electrical conducttance
demineralisation creates porosities
fills with water an ions from saliva
conductivity changes
other methods for caries detection
- Endoscopes
- intraoral cameras
- monitors
- lasers (Quantitative Laser Fluoresence) – depends on the light absorption
- Optical coherence tomography – can detect microstructure differences
- monoclonal antibodies
