Resorption 2 and 3 - External surface, replacement, ortho, pressure, physiol, idiopathic Flashcards
What are the types of external resorption?
- Surface
- Inflammatory
- Replacement
- Invasive
- Orthodontic
- Pressure
- Physiological
- Idiopathic
What are the features of external surface resorption?
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
How is external surface resorption managed?
It is a self-limiting process
Usually heals with new cementum formation (no treatment required)
What is external replacement resorption?
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.
Why does ankylosis happen in external replacement resorption?
PDL is lost and bone fuses to tooth root
How does external replacement resorption relate to ankylosis?
Ankylosis can occur without any resorption and can occur after ALL forms of resorption.
Replacement resorption usually follows ankylosis
What are the types of external replacement resorption?
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
What factors influence external replacement resorption?
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)
How long should the extra-alveolar time be to avoid external replacement resorption?
As short as possible to keep PDL cells alive
12 - 15 minutes are critical in dry storage
How should avulsed teeth be stored?
Ideally in milk, not yoghurt or sour milk
If tissue culture media is available then that is better but it isn’t exactly everywhere….
How does tap water affect avulsed teeth?
Causes rapid cell lysis. Should only be used if nothing else is available and saliva is usually available which is much better
How long can avulsed teeth be stored in saline?
Max 1 hour because it has no nutrients
How long can avulsed teeth be stored in saliva?
Max 2 hours (PDL cells have low resistance to salivary bacteria)
How long can avulsed teeth last in plastic wrap + saliva?
Max 1 hour
How long can avulsed teeth last in milk?
Max 6 hours (ideal pH and osmolarity)
Temperature not important as long as its less than 37 degrees
What are the types of splinting done on avulsed teeth? What are the advantages of each?
Flexible: Allows functional healing of the PD: while reducing ankylosis and replacement resorption
Rigid
When should a flexible splint be used?
If no root or bone fractures
When should rigid splint be used?
If there is a bone fracture (6 weeks) or a root fracture (3 months)
What are the requirements of a splint?
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
What should be avoided with endodontic treatment of avulsed teeth?
Avoid using Ca(OH)2
Avoid immediate root filling
Avoid extra-oral endodontic treatment
What should be used for endodontic treatment of avulsed teeth?
A corticosteroid-antibiotic mixture
How should endodontic treatment be used for external resorption?
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
What are the features of orthodontic resorption?
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
How is orthodontic resorption managed?
Cease orthodontics - but this may not be possible!
Monitor radiographically
Ensure good oral hygiene to avoid periodontal disease
What are the features of pressure resorption?
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)
How is pressure resorption treated?
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.
What are the features of physiological resorption?
Resorption of deciduous teeth during exfoliation
Occurs with or without permanent successor present
But rate may be very slow if no successor
How is physiologic resorption managed?
Usually no treatment required
But: Extract if affecting eruption of permanent tooth
What are the features of idiopathic root resorption?
External resorption of numerous teeth for unknown cause and mechanism.
How does idiopathic root resorption look?
Can be apical resorption creating short roots
OR: may be multiple sites of invasive resorption
How is idiopathic root resorption managed?
History & blood tests: To check for possible systemic causes
Monitor rate of resorption - regular radiographs
Probably extractions eventually + prostheses
