(7) Dental Caries Flashcards
How are caries formed?
Bacteria which ferment carbohydrates and therefore produce acids.
Acids breakdown mineralised tissues
Dentin and cementum organ material is broken down also
What do bacteria breakdown in the tooth?
Decalcification of hard tissues and disintegration of the organic matrix
What do bacteria convert dietary sugars to?
Mainly lactic acid
Also, acetic acid and propionic acids
What is the critical pH?
5.5
How does saliva aid in the balance of demineralisation?
Buffers the acid and allows remineralisation of enamel
What is the pH of resting plaque?
6.5-7
What curve demonstrates the aetiology of dental caries and pH?
Stephens curve
How long does it take for the plaque to fall to pH5 after rinsing with sugar?
2-3 minutes
What does the pH drop indicate about bacteria?
The metabolism of the plaque
What 2 variables effect patient susceptibility to caries?
Intrinsic and extrinsic
What are the intrinsic factors effecting tooth caries susceptibility?
- Enamel composite
- Enamel structure
- Tooth morphology
- Tooth position
What are the extrinsic factors making a patient more susceptible to dental caries?
- Saliva
- Diet
- Use of fluoride
- Immunity
What are the classifications of dental caries by site of attack?
- Pit and fissure caries
- Smooth surface caries
- Cemental or root caries
- Recurrent caries
What are the most common type of caries?
Pit and fissure caries
Where can pit and fissure caries form?
- occlusal surface of molars and premolars
- buccaneers and lingual surfaces of molars
- lingual surfaces of incisors
Where do the smooth surface caries form?
- Interproximal surfaces
Below contact points
- Gingival third of buccal and labial surfaces
Both producing wide open cavities
What type f caries is shown here?
Cemental/ root caries
Why do cemental caries form?
- roots surfaces exposed to oral environment
- periodontal disease
- softened root surface
- shallow cavities with defined cavities
Why do dentine caries form?
The cementum in the cervical region s very thin, if you brush it away or decay takes over, dentin caries can form
Where do recurrent caries form?
Around the margin or at the base of a previously existing restoration
When do recurrent caries occur?
If there isnt a proper sealant on the filling bacteria can go under and cause caries
Fillings can shrink if they are old or not filled well
What are the classification of caries according to the rate of attack?
- rampant (acute) caries
- slow progressive (chronic) caries
- arrested caries
Where do we normally see rampant caries?
In children
What caries are shown here?
Rampant/ acutely caries
How any surfaces of the teeth will be effected on the rampant caries?
Most of the surfaces
What is associated with rampant/ acute caries?
Bottle feeding
Bottles with sugary drinks
What is the most common type of caries and what demographic do they normally form in?
Slowly progressive (chronic) caries
Adults
What happens in slowly progressive/ chronic caries? (Pulp)
Slow, years for the cavity to develop.
The pulp has enough time to form tertiary dentin and sclerotic dentin. Therefore the pup involvement is quite late.
What reaction occurs in the slowly/ chronic caries? And what does it form?
Pulp reaction
Makes sclerotic and tertiary dentin
What is the carie in this ground section?
What is the carie in this ground section?
What is the carie in this ground section?
Arrested caries
What are arrested caries?
• Caries of enamel or dentine or root caries that becomes static and shows no tendency for further progression.
What is the characteristics of arrested caries?
Black and soft
How can you arrest caries? (enamel and dentin)
Enamel
• Approximal lesions could become arrested when adjacent teeth are lost.
Dentine
• Lesions with early sclerosis limit inward spread of caries.
• Deeply stained brown-blackish colour.
