Root Resorption

Question 1

What is the definition of root resorption?

Answer 1

The non bacterial destruction of the dental hard and soft tissue due to the interaction of clastic cells

Question 2

What are the key features of osteoclast cells involved in root resorption?

Answer 2

• very motile
• ruffled boarder
• in contact with dentine

Question 3

What can cause RANKL stimulation?

Answer 3

• parathyroid hormone, B3 and interleukin-1b
• bacterial lipopolysaccharides
• trauma (physical, chemical)
• chronic inflammation

Question 4

What surfaces are involved in preventing the process of root resorption?

Answer 4

1. PDL (protective element against osteoclasts)
2. Cementum (particularly the non-mineralised layer)
3. Predentine (non collagenous component that lies close to pulp)

Question 5

How can root resorption be classified?

Answer 5

Internal and External resorption

Question 6

What types of internal root resorption exist?

Question 7

How do you examine root resorption on a radiograph?

Answer 7

Need 2 angles
- 30 degrees mesial or distal beam shift

Question 8

How do you tell the difference between internal and external root resorption on a radiograph?

Answer 8

Internal
- lose the parallel lines of the root canal system
- root canal system appears wider on radiograph

External
- nothing to do with root canal system
- parallel lines still present
- diffuse radiopacities present over root but parallel lines still present

Question 9

What is the pathogenesis of internal inflammatory root resorption?

Answer 9

• coronal pulp is necrotic
• lesion includes inflammatory and vascular tissue (if perforated will communicate with PDL)
• apical pulp is vital (important as this blood supply drives resorption)
• lesion will continue to progress until apical pulp goes completely necrotic

Question 10

What treatment option is avail able for internal root resorption?

Answer 10

Orthograde endodontics ONLY

Question 11

What types of internal root resorption exist?

Answer 11

• inflammatory
• replacement

Question 12

What type of root resorption is this?

Answer 12

Internal replacement resorption

Question 13

What types of external root resorption exist?

Answer 13

• surface
• inflammatory
• cervical
• replacement

Question 14

How does the PDL appear in external root surface resorption?

Answer 14

PDL normal and intact

Question 15

What is the common aetiology of external surface root resorption?

Answer 15

Orthodontics

Question 16

What is seen on this PA radiograph?

Answer 16

Root resorption of CI root due to ectopic canine
(trabecular pattern suggests its filled in with bone after canine moved away, therefor no treatment)

Question 17

What are the different causes of External Root Surface Resorption?

Answer 17

• orthodontics
• ectopic teeth (eg pressure on roots from these teeth)
• pathological lesions
• idiopathic

Question 18

What is the treatment option for external root surface resorption?

Answer 18

DO NOT DO ENDO (has nothing to do with the resorption)

REMOVE THE SOURCE (eg ectopic tooth / orthodontal brackets)

Question 19

What can you see on this PA radiograph?

Answer 19

• close proximity of restoration to pulp
• large PA radiolucency
• external inflammatory root resorption

Question 20

What is the aetiology of external inflammatory root resorption?

Answer 20

Necrotic pulp (bacterial or dental trauma in origin)
- PA inflammatory lesion precipitates the resorption process

Question 21

What is the treatment option for external inflammatory root resorption?

Answer 21

Remove the cause of inflammation
- orthograde endodontic (re) treatment
- possibly surgical endodontics or XLA

Question 22

What happens if you percuss a tooth with external replacement root resorption?

Answer 22

High pitched note

Question 23

How does external replacement root resorption present on a radiograph?

Answer 23

NO obvious periodontal ligament
- root canal system normal
- PA area normal

Question 24

What is the aetiology of external replacement root resorption? Explain how it works.

Answer 24

Trauma (significant injury to periodontium such that bone and osteoclasts are then in contact with external root dentine and resorption begins)

Question 25

If external replacement resorption occurs in a GROWING patient, what is seen?

Answer 25

Infraocclusion of tooth because it becomes fused to bone.

Question 26

What must you do in patients that are still growing that have external replacement root resorption?

Answer 26

Decoronation to allow bone and periodontium to grown around - then replace space once stopped growing

Question 27

How does external cervical root resorption present clinically?

Answer 27

pink spot colour (haemorrhages if probed)

Question 28

How does external cervical root resorption present on radiographs?

Answer 28

• “apple core” presentation
• Parallel root canal system lines still present

Question 29

What protects the pulp from external cervical root resorption destroying the pulp/root canal system?

Answer 29

Predentine

Question 30

What are some risks for development of external cervical root resorption?

Answer 30

• orthodontics
• trauma
• viral infections
• non vital whitening when heat applied

Question 31

What treatment options are available for external cervical root resorption?

Answer 31

• nothing & monitor
• XLA and prosthetic replacement
• internal repair and orthograde endodontics