Management of occlusal lesions Flashcards
What is primary caries?
Caries occurring on previously sound tooth surface
What is secondary caries?
Primary caries occurring at margin of failing restoration
What is residual caries?
A portion of caries-affected, demineralised tissue left behind before a restoration is placed
This may either be intentional (left on roof of pulp to preserve vitality) or unintentional (during cavity preparation)
What happens microscopically in early white spot lesions?
hydroxyapatite crystals shrink and pores become larger
Why do brown spot lesions occur?
repeated demineralisation and remineralisation which can lead to pigments from blood or food being incorporated into the enamel
What happens initially in caries process?
Arterial flow in pulp increases
- Causes increase in flow rate of dentinal tubular fluid
This fluid acts to flush out bacterial toxins
Fluid also carries antibacterial components (IgG, lactoferrin)
Peritubular dentine gets laid down making the tubules narrower, this reduces the flow of fluid but also creates a barrier to bacteria (sclerosis)
Affected odontoblasts produce reactionary dentine
At this stage, lesion can be arrested
What happens if lesion continues?
Cavitation may occur due to undermined enamel
Caries starts spreading laterally at ADJ
Affected (demineralised) dentine precedes infected dentine
When caries gets close to pulp, then pulp gets inflamed (reversible pulpitis)
Further increase in blood flow and pain receptors are activated
At this stage, the removal of caries is necessary for pulp to heal
What happens if lesion continues even further?
As bacteria approaches pulp, level of inflammation becomes irreversible (irreversible pulpitis)
Removing caries at this point may not preserve the vitality of pulp but may relieve toothache
What are the key features of a healthy pulp?
No symptoms
Normal response to sensitivity tests
What are the key features of reversible pulpitis?
Short and sharp pain to hot/cold (worse with cold)
Pain is caused by fluid movement in tubules
Fully heals once stimulus is removed
What are the key features of irreversible pulpitis?
Prolonged pain (+30 mins)
Often worse with heat
Pulp is irreversibly damaged so requires more complex treatment eg root canal
What are 3 ways to detect caries?
Examine wet and dry
Visual tactile methods using probe/explorer
Bitewing radiographs (difficult to detect occlusal caries)
When is remineralisation possible?
when there is an early smooth surface lesion
in uncavitated dentine lesions
How can we promote remineralisation?
- Diet
- Plaque removal
- Remineralising agents
When should we operate on a lesion?
when small surface lesion may hide a larger surface area of destruction beneath
when it is difficult to predict the rate of progression
lesion is cavitated and dentinal caries can’t be arrest or reversed
What happens if a tooth keeps getting restored over time?
more tooth tissue loss which further weakens the tooth
What is the biological approach in controlling caries?
oral environment is changed to arrest the carious process with a non-restorative cavity control
What can be used in the biological approach to inhibit progression of non-cavitated lesions?
therapeutic fissure seal
If a patient has low caries risk, what is the more ideal treatment?
therapeutic seal
If a patient has high caries risk, what is the more ideal treatment?
operative intervention may be necessary
What are the 3 different methods that can be done in the operative approach?
- Full caries removal
- Selective caries removal
- Stepwise
What do modern approaches consist of?
caries risk assessment
What must be assessed in operative management?
pulp health and status
extent of caries
How to preserve pulp vitality during restoration?
avoiding plural exposure
What are the main principles in operative management?
Clear EDJ
Minimise removal of sound tooth tissue
Leave dentine that’s capable of repair
Seal cavity to halt bacterial progression
Pulp protection
