L8 Pulpitis

Question 1

What is pulpitis?

Answer 1

The inflammatory response to tissue damage of pulp.

Question 2

How is the pulp affected in caries?

Answer 2

• Tooth surface cavitates
• Bacteria enters cavity and dentinal tubules
• Products of bacterial metabolism penetrate along tubules to reach pulp
• These products damage cells of the pulp including odontoblasts

Question 3

Pulp can be classified according to what 2 factors?

Answer 3

Clinical classification:

• Acute
• Chronic

Pathological classification:

• Parital or total
• Open or closed (open = coronal pulp is open to oral cavity)
• Exudative (serum based) or suppurative (pus based)

Question 4

Describe the clinical presentation of pulptitis.

Answer 4

• Predominantly pain but some patients will present without pain
• Pain will be difficult to localise to a specific tooth, pain may radiate to adjacent jaw and sometimes to the face, ear and neck
• Pain may be continuous or intermittent

Question 5

What are the clinical signs of acute pulptitis?

Answer 5

Severe, throbbing pain.
Made worse by hot or cold, and lying down.
May keep patient awake.

Question 6

What are the clinical signs of chronic pulpitis?

Answer 6

Spontaneous attacks of dull, aching pain.

Lasts 1-2 hours.

Question 7

What is the difference between reversible and irreversible pulpitis?

Answer 7

• Reversible pulptitis: restorative treatment will cause pulpitis to resolve
• Irreversible pulpitis: no matter what intervention, pulpal inflammation is likely to persist and ultimately cause total pulp necrosis

Question 8

What does pulp management depend on?

Answer 8

• Patient age
• Size of carious lesion
• Presence of symptoms
• Vitality testing
• Radiographic changes

Question 9

Describe physical causes of pulpitis.

Answer 9

Physical trauma:

• Tooth fracture
• Cracked tooth
• Iatrogenic (e.g. during cavity preparation)

Question 10

Describe microbial causes of pulpitis.

Answer 10

Microbial:

• Bacteria and bacterial products reach the plup as a result of caries
• Pulp changes seen when bacteria are 1mm from pulp in adult teeth, 2mm from pulp in deciduous teeth

Question 11

Describe chemical causes of pulpitis.

Answer 11

Chemical:

• Irritant chemicals reach pulp by diffusing through dentinal tubules e.g. during restorative treatment
• Iatrogenic: applied directly to exposed pulp during restorative treatment

Question 12

Describe thermal causes of pulpitis.

Answer 12

Thermal:

• Heat generated by friction in cavity preparation
• Unlined large metallic fillings may transmit thermal changes to the pulp (e.g amalgam in contact with gold)

Question 13

What factors may modify the inflammatory process?

Answer 13

• Local anatomy of the pulp chamber
• Nature of the damaging agent
• Duration and severity of tissue damage
• Pre-existing state of the pulp
• Host defences
• Apical blood flow: whether the apical foramen is already closed, or if tooth is still developing and apex still open

Question 14

How can pulpitis lead to total pulp necrosis?

Answer 14

• Increased vascular permeability causes inflammatory exudate to enter pulp chamber
• Local rise in tissue pressure could cause local collapse of venous part of microcirculation
• Local tissue hypoxia and anoxia produces further tissue damage, and further inflammation causes increase in pressure
• Can lead to total pulp necrosis

Question 15

What is the main host defence against pulpitis?

Answer 15

Reparative dentine formation:

• Begins 20 days after initial damage
• Produced at rate of 0.1mm over next 100 days

Question 16

What tissue type may be seen in pulpitis?

Answer 16

Granulation tissue

Question 17

What immune cells may be present in pulpitis?

Answer 17

Lymphocytes (large dark nucleus), plasma cells (odd positioned nucleus) and macrophages (pale nucleus).

NB: loss of odontoblasts

Question 18

Pulpitis progression depends on what?

Answer 18

• Severity and duration of tissue damage
• Properties of the bacteria
• Host resistance

Question 19

How do neutrophils reach the pulp tissue and what can neutrophil accumulation cause?

Answer 19

• When bacteria reach the pulp there is vascular dilation
• Neutrophils migrate from vessels
• Majority of pulp entering the pulp is destroyed by neutrophils and other defence mechanisms
• Local tissue necrosis and neutrophil accumulation leads to suppuration (pulp abscess)

Question 20

Describe the cellular composition of a pulp abscess.

Answer 20

• Necrotic tissue with many neutrophils (multi-lobed nucleus)
• Almost no viable tissue remaining

Question 21

What membrane may form around a pulp abscess?

Answer 21

A pyogenic membrane (made of granulation tissue)

Question 22

How can a pulp abscess cause pulp necrosis?

Answer 22

Abscess may extend through the pulp, causing necrosis.

Question 23

What is pulp necrosis?

Answer 23

Inflammation of the entire pulp, reaches the root apices. Pulp completely dead.

Question 24

What is a pulp polyp?

Answer 24

• A pink soft tissue swelling attached to the dental pulp
• Seen as bright red or pink soft tissue mass within large carious caivty
• Seen in primary teeth or
  permanent teeth with wide
  open root apices thus pulp
  has good blood supply
• Core of dense fibrous tissue, oftem with squamous epithelium on surface to protect from bacteria
• Called chronic hyperplastic pulpitis

Question 25

Describe the formation and structure of a pulp polyp.

Answer 25

• Large area of inflamed pulp
• Causes granulation tissue to proliferate and produces a nodule of tissue (polyp)
• Surface may epithelialise and can be keratinised (keratinised stratified squamous epithelium)
• Underlying tissue is vascularised connective tissue

Question 26

What happens once the surface of a polyp epithelialises?

Answer 26

The core is largely protected from the oral environment, so inflammation will reduce and granulation tissue replaced by fibrous scar tissue.

Question 27

What are the theories regarding the origins of the epithelial layer on pulp polyps?

Answer 27

• Said to be from desquamated epithelial cells but these are usually inactive cells incapable of division
• May be some epithelial basal cells in saliva, possibly released by trauma