Endodontics L1: Pulpal and Periapical pathology

Question 1

Q21: the host response to invasion of microbes in the pulp is both inflammatory and immunological. The activation of T and B lymphocyte, macrophages, and dendritic cells is an example of which response?

Answer 1

Immunological

Question 2

Q11: bacterial invasion of dentinal tubules occurs more rapidly when the pulp is what?

Answer 2

Bacterial invasion of dentinal tubules occurs more rapidly with a nonvital (necrotic) pulp compared to a vital pulp.

Question 3

Q19: once the pulpal tissue has been breached by the microbes it can remain inflamed for a long time or undergoes necrosis slowly or rapidly. The speed at which it undergoes necrosis is dependant on which factors.

Answer 3

Bacterial virulence,

inflammatory response

host resistance,

amount of circulation and lymphatic drainage.

Question 4

Q3: apical lesions are referred to as protection with a price tag, why?

Answer 4

Apical lesions protect surrounding apical bone by localising the infection, by doing so it results in the destruction of the apical bone where it is contained.

Question 5

Q29: as the disease progresses down the root canal, do you see an increase in gram negative or gram-positive bacteria?

Answer 5

Increase in gram negative

Question 6

Q6: with a vital pulp, how does it offer protection in reference to its type of dentine?

Answer 6

The pulp contains tertiary dentine also known as reparative dentine. This type of dentine is formed when the odontoblast undergoes trauma by thermal, chemical, mechanical, and bacterial.

Question 7

Q27: what is an obligate anaerobe?

Answer 7

An anaerobe that can live only in the absence of oxygen

Question 8

Q23: an increase in lesion progression will result in what in the pulp chamber?

Answer 8

Increased tissue pressure

Question 9

Q33: which region would you expect to find a lower oxygen tension?

Answer 9

Apical region

Question 10

Q17: once the pulp is exposed, it becomes infiltrated by?

Answer 10

Polymorphonucleocytes

Question 11

Q18: once the pulp is exposed, it becomes infiltrated by polymorphonucleocytes to form an area of liquefaction necrosis at the site of exposure, what is liquefaction necrosis?

Answer 11

Liquefaction necrosis is characterized by partial or complete dissolution of dead tissue and transformation into a liquid, viscous mass.

Question 12

Q25: why does the speed of the infection quicken once pulpal necrosis has occurred?

Answer 12

With pulpal necrosis the pulp has lost its ability to protect itself.

Question 13

Q9: what two must be present for the development of apical periodontitis?

Answer 13

Necrotic pulp and microbial infection.

Question 14

Q13: microorganisms produce microbial irritants such as toxins and by-products, resulting in the infiltration of chronic inflammatory cells such as?

Answer 14

Macrophages, lymphocytes, and plasma cells.

Question 15

Q15: impact injuries where the crown remains intact can still affect the pulp in which way? I.

Answer 15

mpact injuries may result in the formation of microcracks in the enamel, which will allow bacteria to reach the pulp

Question 16

Q4: with a vital pulp, how does it offer protection in reference to its movement of dentinal fluid?

Answer 16

The pulp moves dentinal fluid in an outward movement, if pathogenic material is present in dentinal fluid, then the mechanism pushes the fluid towards the enamel.

Question 17

Q24: due to the enclosed pulp chamber, and the inability of the pulpal tissue to expand and the lack of collateral circulation, will eventually result in what?

Answer 17

Pulpal necrosis

Question 18

Q32: which region would you expect to find a higher oxygen tension?

Answer 18

Coronal region

Question 19

Q34: which region would you expect to find a lower bacterial count?

Answer 19

Apical region

Question 20

Q20: the host response to invasion of microbes in the pulp is both inflammatory and immunological. The activation of histamine, bradykinin, arachidonic acid and neuropeptides is an example of which response?

Answer 20

Inflammatory

Question 21

Q8: if a pulp is vital it can protect itself against bacterial invasion and colonization, host defence do not function when the pulp is what?

Answer 21

Necrotic

Question 22

Q7: dentinal exposure does not represent a significant route of infection except when dentine’s physiology has been compromised such as?

Answer 22

Dentine thickness is reduced, or dentine permeability increased.

Question 23

Q5: with a vital pulp, how does it offer protection in reference to its tubular contents?

Answer 23

Dentinal tubules contain immune cells and many other cells which pathogenic material must encounter first before the pulp.

Question 24

35: which region would you expect to find a higher bacterial count?

Answer 24

Coronal region

Question 25

Q22: the establishment of primary endodontic infections requires the elimination of what?

Answer 25

Pulpal necrosis

Question 26

Q1: what is apical periodontitis?

Answer 26

An inflammatory disease of microbial aetiology caused by infection of the root canal system which results in bone resorption around the root(s).

Question 27

Q10: how does caries contribute to the routes of root can infection?

Answer 27

Caries allows bacterial penetration of tubules and destruction of dentine.

Question 28

Q11: pulp becomes inflamed when bacteria is ………………. Away?

Answer 28

0.5mm

Question 29

Q16: routes for root canal infections such as crown/bridge preparation,

accidental exposure,

inadequate water spray on high speed drill,

over drying exposed dentine,

inadequate isolation of teeth from saliva,

failure to adequality protect and seal tubules.

Are examples of which factor that allows routes for root canal infection.

Answer 29

iatrogenic factors

Question 30

Q31: infection is a dynamic process and different species dominate at different stages; what three factors determine differentiation is species.

Answer 30

Availability of nutrition, oxygen level, and local pH.

Question 31

Q2: what is an apical lesion?

Answer 31

Apical lesions represent a protective activity of the host response. It prevents pathogenic bacteria present in infected root canals from spreading into adjacent bone and to other remote places in the body.

Question 32

Q26: what is a facultative anaerobe?

Answer 32

A facultative anaerobe is an organism that makes ATP by aerobic respiration if oxygen is present but can switch to fermentation if oxygen is absent.

Question 34

Q28: how does gram negative bacteria differ from gram positive?

Answer 34

Gram positive have a thick peptidoglycan layer and no outer lipid membrane, whilst gram negative has a thin peptidoglycan layer and has a outer lipid membrane

Question 35

Q14: traumatic accident, iatrogenic damage during dental procedure, excessive orthodontic procedures, subgingival scaling, attrition/abrasion. Are all examples of what type of injury to the pulp?

Answer 35

Mechanical injury to the pulp.

Question 36

Q30: can you name the 9 most common endodontic microbes:

Answer 36

Prevotella,

Porphyromonas,

fusobacterium,

Veillonella,

Pepto streptococcus,

eubacterium,

actinomyces,

lactobacillus,

streptococcus.

Question 37

Q12: a microbial diameter ranges from 0.2-0.7um, what is the diameter of the tubules near the pulp?

Answer 37

2.5um