Resorption 2 and 3 - External surface, replacement, ortho, pressure, physiol, idiopathic

Question 1

What are the types of external resorption?

Answer 1

1. Surface
2. Inflammatory
3. Replacement
4. Invasive
5. Orthodontic
6. Pressure
7. Physiological
8. Idiopathic

Question 2

What are the features of external surface resorption?

Answer 2

Small resorption areas usually only in cementum but may extend to a shallow depth into the dentine

Often due to localised injury to the PDL and the cementum

Question 3

How is external surface resorption managed?

Answer 3

It is a self-limiting process

Usually heals with new cementum formation (no treatment required)

Question 4

What is external replacement resorption?

Answer 4

Condition in which tooth structure is lost and replaced by bone externally. Ankylosis is often seen in this condition.

The name external replacement resorption is inappropriate and confusing as it describes what it is related to rather than what is happening.

Question 5

Why does ankylosis happen in external replacement resorption?

Answer 5

PDL is lost and bone fuses to tooth root

Question 6

How does external replacement resorption relate to ankylosis?

Answer 6

Ankylosis can occur without any resorption and can occur after ALL forms of resorption.

Replacement resorption usually follows ankylosis

Question 7

What are the types of external replacement resorption?

Answer 7

Progressive: Associated with drying or removal of the PDL and gradually involves the entire root.

Transient: Minor areas of damage, later it disappears and normal PDL forms

Question 8

What factors influence external replacement resorption?

Answer 8

Extra-alveolar time (how long it was out of the socket)

Storage conditions (osmolarity, pH, and temp conditions ideal for viability of the PDL cells)

Damage during injury and repositioning (hard to control but minimised trauma if replaced by the dentist)

Splinting

Endodontic treatment (use of toxic materials may destroy PDL cells hence more replacement resorption occurs)

Question 9

How long should the extra-alveolar time be to avoid external replacement resorption?

Answer 9

As short as possible to keep PDL cells alive

12 - 15 minutes are critical in dry storage

Question 10

How should avulsed teeth be stored?

Answer 10

Ideally in milk, not yoghurt or sour milk

If tissue culture media is available then that is better but it isn’t exactly everywhere….

Question 11

How does tap water affect avulsed teeth?

Answer 11

Causes rapid cell lysis. Should only be used if nothing else is available and saliva is usually available which is much better

Question 12

How long can avulsed teeth be stored in saline?

Answer 12

Max 1 hour because it has no nutrients

Question 13

How long can avulsed teeth be stored in saliva?

Answer 13

Max 2 hours (PDL cells have low resistance to salivary bacteria)

Question 14

How long can avulsed teeth last in plastic wrap + saliva?

Answer 14

Max 1 hour

Question 15

How long can avulsed teeth last in milk?

Answer 15

Max 6 hours (ideal pH and osmolarity)

Temperature not important as long as its less than 37 degrees

Question 16

What are the types of splinting done on avulsed teeth? What are the advantages of each?

Answer 16

Flexible: Allows functional healing of the PD: while reducing ankylosis and replacement resorption

Rigid

Question 17

When should a flexible splint be used?

Answer 17

If no root or bone fractures

Question 18

When should rigid splint be used?

Answer 18

If there is a bone fracture (6 weeks) or a root fracture (3 months)

Question 19

What are the requirements of a splint?

Answer 19

Keep it simple

Avoid gingival tissues

Allow interproximal cleaning (instruct patient how to clean)

Check tooth position radiographically

Relieve from occlusion and check with articulating paper

Question 20

What should be avoided with endodontic treatment of avulsed teeth?

Answer 20

Avoid using Ca(OH)2

Avoid immediate root filling

Avoid extra-oral endodontic treatment

Question 21

What should be used for endodontic treatment of avulsed teeth?

Answer 21

A corticosteroid-antibiotic mixture

Question 22

How should endodontic treatment be used for external resorption?

Answer 22

Endodontic treatment can not arrest or treat external replacement resorption since it is due to PDL and root surface damage.

Only do endodontics to prevent or treat external
inflammatory resorption

Question 23

What are the features of orthodontic resorption?

Answer 23

Due to forces applied during orthodontic treatment

Shortened tooth root with rounded or blunt apex

More common & more severe in upper incisors

PDL and pulp are normal - unless concurrent disease

Question 24

How is orthodontic resorption managed?

Answer 24

Cease orthodontics - but this may not be possible!

Monitor radiographically

Ensure good oral hygiene to avoid periodontal disease

Question 25

What are the features of pressure resorption?

Answer 25

Associated with impacted teeth or other pathosis
e.g. cysts, tumours

Resorption caused by pressure on the tooth root

PDL and pulp are normal (unless concurrent disease)

Question 26

How is pressure resorption treated?

Answer 26

If caused by cyst or tumour - curette the lesion and watch/reassess resorbing tooth

If caused by impacted tooth, extract the tooth then watch and reassess especially the pulp.

OR extract both impacted and resorbing tooth.

Question 27

What are the features of physiological resorption?

Answer 27

Resorption of deciduous teeth during exfoliation

Occurs with or without permanent successor present

But rate may be very slow if no successor

Question 28

How is physiologic resorption managed?

Answer 28

Usually no treatment required

But: Extract if affecting eruption of permanent tooth

Question 29

What are the features of idiopathic root resorption?

Answer 29

External resorption of numerous teeth for unknown cause and mechanism.

Question 30

How does idiopathic root resorption look?

Answer 30

Can be apical resorption creating short roots

OR: may be multiple sites of invasive resorption

Question 31

How is idiopathic root resorption managed?

Answer 31

History & blood tests: To check for possible systemic causes

Monitor rate of resorption - regular radiographs

Probably extractions eventually + prostheses