Caries I & II

• What are the 2 types of MI dentistry?

  1. Minimum Intervention Dentistry
  2. Minimally Invasive Dentistry
• What is Minimally Invasive Dentistry?

  Active lesions can be 'sealed and healed'

  Mechanistic approaches to caries removal is no longer recommended.
• What are the 4 steps to the Minimum Intervention Oral Care Plan?


  1. Identify
  2. Prevent and control- using a care plamn
  3. MI Restore- invasive or non-invasive
  4. Recall
• What is dental caries?

  A reversible disease of dental hard tissues, instigated by the action of bacteria upon fermentable carbohydrates in the plaque biofilm at tooth surfaces, leading to the formation of carious lesions caused by acid demineralisation and proteolytic destruction of the organic component of dental tissues.
• Define a carious process.

  The histopathological metabolic interactions occurring in the plaque biofilm causing disease.
• Define a carious lesion.

  The signs of the disease on dental hard tissues- i.e. early lesions/discolouration
• What are the 4 'causative' factors to caries according to the acidogenic theory?

  1. Bacteria- e.g. Streptococcus Mutans
  2. Tooth Surface
  3. Carbohydrate
  4. Time
• What 3 things drive a low pH, leading to carious enamel?

  1. Plaque
  2. Carbohydrate
  3. Time
• What 4 things drive a high pH, leading to sound enamel?

  1. Saliva
  2. Good Oral Hygiene
  3. Good diet
  4. Fluoride
• What is the critical pH of dentine and enamel?

  Dentine = 6.2

  Enamel = 5.5
• What does the critical pHs of both dentine and enamel suggest about dentine and why?

  Dentine is more susceptible as it requires less of a pH drop to cause damage to it.
• What are the 4 steps in the caries diagnostic regime?

  1. Remove calculus, plaque and stains
  2. Dry the tooth using 3in1
  3. Early Clinical detection
  4. Diagnosis and treatment
• What special investigations are used to detect caries?

  1. Vitality tests
  2. Radiographs
• What does the ecological and extended ecological plaque hypothesis conclude?

  Some plaque is sometimes good, but if it stagnates a lesion can form. This is called Cariogenic dysbiosis.
• What is the term when too much plaque stagnates on a tooth?

  Cariogenic dysbiosis.
• What 2 bacteria increase susceptibility to caries?

  Streptococcus mutans

  Lactobacilli
• What are the 3 levels of caries risk?

  
  

  Caries risk is the potential of an individual developing further caries and responding to treatment of current disease

  1. LOW - Caries inactive/controlled.

  There is 0-1 active lesions and no history of recent restorations

  2. MEDIUM - Caries active/modifiable risk factors.

  More than 1 active lesion and history of more than 1 filled lesion in last 2-3 years

  3. HIGH - Caries active/UNmodifiable or UNIDENTIFIABLE risk factors.

  More than 1 active lesion and history of more than 1 filled lesion in last 2-3 years
• How are the 3 levels of caries treated?

  LOW - Oral hygiene and Fluoride

  MEDIUM- Oral hygiene, fluoride and dietary modification

  HIGH- Control at individual pt. level, salivary flow stimulation.
• How does porosity occur?

  Deminerilisation occurs beneath the surface of the enamel as biofilm sits on the surface and produces acid, reducing the pH to below 5.5, causing dissociation of the mineral within the enamel.

  Overlying enamel starts to remineralise, so the surface mineralises. The subsurface remains demineralised - leading to porosity.
• What is the composition of enamel?

  95% Mineral (CO3 and Hydroxyapatite)

  5% Organic (amelogenins, enamelins, albumin)

  Water
• How are enamel crystals arranged?


  As Type III prisms in lock and key.
• What do enamel prism boundaries contain?

  Organic matrix (amelin I, II, albumin)
• What part of the enamel suffers the most acid demineralisation?

  Enamel prisms and boundaries.
• What is the progression of caries on enamel?

  1. White spot lesion - chalky and softened (early)
  2. Brown spot lesion (later)
• What is the composition of dentine?

  70% hydroxyapatite

  20% Organic (Type I collagen)

  10% water
• What in dentine is involved in the matrix and mineralisation process?

  1. Gla-proteins
  2. Plasma proteins
• Where does dentine run from and to?

  AMJ (amelo-dentinal junction) to the pulpal border
• What are dentine tubules made up of?

  Peri-tubular and inter-tubular dentine.
• What 3 things are dentine susceptible to biochemically?

  1. Demineralisation from lactic acid and acetic acid
  2. Bacterial penetration via tubules and branches
  3. Proteolysis - host enzymes breakdown collagen fibers embedded in the dentine mineral matrix
• What are 3 clinical effects of demineralisation on dentine?

  1. Brown pigmentation due to the Maillard reaction- which is a reaction between proteins and carbohydrates in an acidic environment.
  2. Dentine becomes SOFT
  3. Dentine-pulp complex defence reaction- translucent dentine forms in tubules and tertiary (reparative dentine) at the pulp border also forms.
• In terms of hardness what is the trend from enamel to the pulp wall?

  Hardness increases, then in the transparent zone with translucent it becomes softer, then increases with sound dentine. Then from sound dentine to the pulpal wall hardness decreases.
• What are the 3 reactions from the dental-pulp complex in response to a carious process?

  1. Translucent dentine
  2. Reparative dentine
  3. Inflammation/serum proteins in pulpal fluid
• What is the caries iceberg used for?

  To rank lesions

  Clinically detectable lesions are divided into four groups, D1–D4, depending on the depth of tissue invasion and the degree of cavitation.
• What does D1-D4 indicate on the caries iceberg?

  D1- Clinically detectable enamel lesions with ‘intact’ surfaces.

  D2- Clinically detectable cavities limited to enamel

  D3- Clinically detectable lesions in dentin (open and closed)

  D4- Lesions in pulp

  
• What does ICDAS stand for and what are the 5 rankings?(1)

  International Caries Detection & Assessment System

  0 - No or slight change in enamel translucency after air drying, no enamel deminerilisation.

  1 - Opacity/discolouration is hardly visible, but distinctly visible after air drying, enamel demineralisation is limited to outer 50% of the enamel layer.

  2 - Opacity or discolouration distinctly visible without air drying but still no clinical cavitation detectable, demineralisation involving between 50% of the enamel and outer 1/3 of dentine.

  
• What does ICDAS stand for and what are the 5 rankings?(2)

  3 - Localised enamel breakdown in opaque or discoloured enamel +/- greyish discolouration from underlying dentine, demineralisation involving the middle 1/3 of dentine.

  4 - Cavitation in opaque/discoloured enamel exposing the underlying dentine, demineralisation involving the inner 1/3 of dentine.

  
• How many types of enamel lesions are there and how many types of dentine lesions are there?

  2 enamel- E1,E2

  3 dentine- D1,D2,D3
• What ICDAS score do each of the enamel and dentine lesions have?

  E1- Outer half of enamel- 0,1

  E2- Inner half of enamel- 1,2

  D1- Outer 1/3 of dentine- 2

  D2- Middle 1/3 of dentine- 3

  D3- Inner 1/3 of dentine- 4
• What is a critical indicator for potential lesion activity?

  Surface plaque stagnation.
• What is the difference between infected and affected dentine?

  Infected dentine- massive amount of demineralisation- dentine has denatured

  Affected dentine- demineralisation is less- dentine is damaged not denatured so can be repaired!