Week 6 Rodrigo- Intro to endo

Question 1

What is the dental pulp composed of?

Answer 1

• Odontoblasts
• Fibroblasts
• Other cells (during inflammatory responses)
• Vessels
• Nerves
• Intercellular ground substance

Question 2

What is intercellular ground substance?

Answer 2

Transparent colourless and fills space between fibres and cells. Rich in proteoglycans, glycoproteins, large amounts of water

Question 3

What are odontoblasts + where are they located?

Answer 3

• These cells are responsible for the secretion of dentin and the formation of dentinal tubules in the crown and root.
• Aligned along predentine
• Odontoplast processes is housed within dentinal tubule (⅓-½ of tubule)
• Considered terminal cells

Question 4

Most prevalent cell in the pulp?

Answer 4

Fibroblasts

Question 5

What are fibroblasts?

Answer 5

Their function is to form and maintain the pulp extracellular matrix. It consists of collagens and non collagenous proteins.

Question 6

What is the sensory innervation of pulp?

Answer 6

Three types of trigeminal sensory nerve fibres:

• A Beta
• A Delta fibres
• C fibres

Question 7

What nerve fibes are activated for sharp, immediate pain- cold?

Answer 7

A fibres

They are myelinated with very fast conduction speed and a low excitability
threshold. They mediate the sharp, transient pain typical of dentin sensitivity.

Question 8

What nerve fibres are activated for dull, lingering pain? Why?

Answer 8

C fibres

Unmyelinated, with slow conduction speed and high excitability threshold. Produces pain that is dull, aching, excruciating, and sometimes diffuse, typical of symptomatic irreversible pulpitis.

Question 9

Describe risk of infection when dentine is exposed?

Answer 9

Once exposed, dentin may represent route for bacteria to reach the pulp via tubules. However, as long as the pulp is vital, dentinal exposure does not represent a significant route of pulp infection, except when dentin thickness is considerably reduced, and dentin permeability is significantly increased.

Question 10

What are pathways of root infection?

Answer 10

• Caries
• Perio pocket reaching lateral canal
• Pocket reaching apex
• During procedure (pulp exposure)
• Attrition
• Trauma

Question 11

Describe histology of reversible to irreversible pulpitis?

Answer 11

In irreversible pulpitis, there is limited extension of necrosis of pulp associated with bacterial colonisation. Not all of pulp is infected.

Question 12

Describe impact of bacterial load on signs/symptoms of patient

Answer 12

• Bacteria have to reach a quorum of cells sufficient to cause disease and clinical signs/symptoms
• After bacterial levels exceed this threshold, infectious disease (apical periodontitis) is established
• If treatment procedures do not succeed in reducing bacterial levels below that threshold, the disease will persist.

Question 13

What is an adjunctive measure to reduce bacterial load in endo?

Answer 13

Laser (antimicrobial photodynamic therapy)

Stain bacterial blue which attracts light to disrupt membrane

Question 14

What is patency?

Answer 14

Preparation technique in which the apical region of the root canal is maintained as free of debris by recapitulating through the apical constriction with a fine file (size 10 or 15)

Question 15

Compare prognosis of teeth with pulpitis vs periapical disease

Answer 15

Teeth with vital and inflamed pulp have significantly higher rate of success compared with teeth with pulp space infection and periapical disease