management of caries Flashcards
What is dental caries?
Reversible but progressive
Bacteria upon fermentable carbs in the plaque biofilm on tooth surfaces
Leads to acid demineralisation and proteolytic destruction of dental tissues
What is Keyes’ triad?
Tooth, micro flora, diet and time=tooth decay
What are the three most common susceptible tooth sites?
Pits and fissures of occlusal surfaces of posterior teeth
Area below contact point
Surface adjacent to gingival margin
How do carious lesions develop?
An imbalance in favour of pathologic factors over a sustained period of time
Protective vs pathological
What is an early carious lesion?
Non-cavitated and limited to enamel- white spot lesion
Don’t need operative intervention but need preventative
What is the Stephan Curve?
The intra oral pH which is typically 7-6.5 will drop below the critical pH 5.5 for about 8 mins or so
There’s a net loss of minerals
If this continues over time- caries
Saliva remineralises
How might a white spot lesion progress?
No change in oral environment
Demineralisation progresses, weakens enamel, reaches ADJ
Reaches dentine and spreads along ADJ
Enamel breaks under occlusal forces=cavity
Why does a cavity require operative intervention?
Can’t feasibly remove plaque
Bacteria remains, food gets stuck
Progression much quicker in dentine
What is infected dentine?
Outermost, irreparable, necrotic zone Dark, mushy, wet, soft Denatured collagen matrix High bacterial load Tubular structure destroyed
What is affected dentine?
Inner layer, reparable Paler brown, harder, leathery Collagen damaged to lesser extent Less bacterial load Tubular structure foundations remain Unnecessary to remove
How do you detect caries?
Magnify Illuminate Clean Blunt ended probe- round/ball 3-in-1 air/water syringe
What special tests may be used to identify caries?
Radiographs Transillumination Quantitative Laser Fluorescence Electrical Impedance devices Tooth separation w ortho devices
How can caries be controlled non-operatively?
Oral hygiene instructions Plaque control Diet advice Fluoride CPP-ACP Antimicrobial agents (chlorhexidine, xylitol)
What is CPP-ACP?
Casein phosphopeptide-Amorphous Calcium Phosphate
Tooth mousse
Provides calcium and phosphates
Eg. Every couple of hours
What are the three aims of operative management?
- Aid plaque control to manage caries
- Protect pulp-dentine complex and arrest lesion by sealing
- Restore function, form and aesthetics
What are three caries removal techniques?
Complete caries removal
Stepwise caries removal
Partial caries removal
What is complete caries removal?
Removal of ALL carious tissue
Leaves sound enamel and dentine
Completely clean
~ outdated, removes healthy and increases pulpal complications
What is Stepwise caries removal?
Appt 1- open cavity, remove infected dentine and place temp restoration for 2-6 months
Appt 2- remove restoration, remaining caries at base and place definitive restoration
~ lower pulp exposure chance due to tertiary dentine being placed
What is partial caries removal?
Selective removal of all carious enamel and infected dentine
Leave affected dentine at base
Leave sound enamel, sound dentine at ADJ
~ removes less tooth and preserves pulp vitality
What are the steps of caries removal?
- Enamel access
- Clear ADJ, sound margins
- Management of unsupported enamel
- Management of body of carious lesion
What hand instruments are used to remove caries?
Chisels- gingival margin trimmers, hatchets and straight chisels
~manage carious and unsupported enamel
Excavators- spoon exc.
~remove carious dentine and clear ADJ
What are the advantages of hand instruments?
Controlled removal
Tactile feedback
Simple and cheap
No noise or vibration
What are the disadvantages of hand instruments?
Time consuming
Exclusive use limited to open cavities
Operator fatigue
What rotary instruments are used to remove caries?
High speed handpiece/air rotor- ~air powered (pneumatic) ~up to 450000rpm ~internal water cooling system ~friction grip burs (pear and round diamond) Slow handpiece/contra-angle- ~powered by motor ~modifiable speed, 40000rpm ~may not have internal water cooling ~latch grip burs (rose-head)
What are the advantages of rotary instruments?
More efficient
Used for any type of lesion
Tactile feedback
Versatile- diff speeds, burs, angulations
What are the disadvantages of rotary instruments?
Noise/vibrations
Significant heat- cooling required
Less control
Produce aerosol
What is chemo-mechanical caries removal?
Proteolytic chemical breaks down organic tissue in caries
Removed w excavators
Eg. Carisolv, Papacarie
What are the advantages of chemo-mechanical?
Controlled removal
Tactile feedback
Reduce need for local anaesthetic
No noise/vibration
What are the disadvantages of chemo-mechanical?
Time consuming
Limited to open cavities
Selective removal claims not proven
More fatiguing
What about other techniques eg. Air abrasion, lasers, ultrasonic?
Reduce need for anaesthetic Improve patient comfort Air abrasion- improve bonding for composite But Time consuming Expensive Lack of tactile feedback Can’t remove soft caries
