Resorption 4 - external inflammatory resorption Flashcards
What is external inflammatory resorption?
An inflammatory process that results in loss of tooth structure and loss of adjacent bone
What is required for external inflammatory resorption diagnosis?
An infected RCS + Communication pathway from root canal to the PDL
How does external inflammatory resorption occur?
Bacteria/endotoxins diffuse through dentinal tubules
Leukocytes cannot reach the bacteria in the canal/tubules
Clastic cells activated to resorb bone and dentin
What triggers can lead to external inflammatory resorption?
Can occur after trauma where the pulp necroses and becomes infected + there has been damage to the PDL and the cementum
Can also occur with long-standing infected root canal systems via the apical and/or lateral canal foramina
What are the types of external inflammatory resorption?
Apical and lateral commonly
When does external inflammatory resorption typically occur?
After traum (luxation, avulsion, etc)
With long-standing infected root canals
With concurrent endo/perio diseases
What are the clinical features of external inflammatory resorption typically?
History of trauma, infected RCS, etc
Pulp sensibility tests - no response
Other signs/symptoms of an infected RCS
What are the radiographic features of external root resorption?
Loss of external tooth substance
Radiolucency in adjacent bone
What factors does external inflammatory resorption following trauma depend on?
External Inflammatory Resorption following trauma
depends on several factors:
The type of injury - especially luxations, avulsion
The severity of the injury
Stage of root development
How likely is pulp necrosis and infection
Any concurrent injury
How likely is damage to the PDL and cementum in traumatic injuries?
Depends on the type of injury in order of lowest to highest:
Concussion
Subluxation
Extrusion
Lateral luxation
Intrusion
Avulsion
How likely is pulp necrosis?
Depends on the type of injury:
Luxations, avulsions, root fractures depends on how severe the blood supply was damaged apically or at the fracture line and the pulp’s ability to revascularize.
In subluxation, concussion, and crown fractures it depends on the pulp’s ability to resist bacterial invasion and whether any pathways exist for bacteria to enter the tooth.
How can bacteria enter the root canal system following trauma?
Bacterial Pathways:
Infractions
Uncomplicated Crown Fractures
Dentine exposed
Complicated Crown Fractures
Pulp exposed
How can bacteria enter the root canal system following trauma?
Bacterial Pathways:
Infractions
Uncomplicated Crown Fractures: Dentine exposed
Complicated Crown Fractures: Pulp exposed
What approach should be taken in injuries where the root surface and PDL are damaged + pulp necrosis and infection are predictable?
A preventative approach should be taken to prevent external inflammatory resorption
What were the effects of doxycycline in replanted monkey incisors?
Increased frequency of pulp revascularization
Decreased frequency of micro-organisms in the pulp space
Decreased frequency of ankylosis, replacement resorption, and inflammatory root resorption
What are the non-antimicrobial actions of tetracyclines?
They modulate host responses:
they inhibit osteoclast function
They bond to bone and teeth which slows release and prolongs action
How should dexamathasone be used for periodontal healing of replanted dogs’ teeth?
Topical use of dexamethasone enhances healing and results in fewer resorption complications
How are dentinoclasts affected by demeclocycline and ledermix paste? what does this indicate?
demeclocycline: Cells are well-spread and still attached after 24 hours
Ledermix paste: Cells not spreading, more spherical shaped, no dentinoclasts evident after 18 hours
Indicates that the steroid component does the direct inhibition of dentinoclasts.
The antibiotic component contributes to the therapeutic effect on inflammatory resorption by killing bacteria in the root canal and dentine tubules
What ratedoes ledermix paste diffuse through the dentinal tubules?
Rate is very high on the first day and then therapeutic release is maintained until approximately the 6 week mark in mature teeth and 4 weeks in immature teeth.
How does ledermix paste compare to Ca(OH)2 for root resorption?
Teeth immediately treated with ledermix paste exhibited significantly more healing and less resorption and maintained more residual root mass than those treated with Ca(OH)2
What was the effect of Ca(OH)2 in the experimentally-induced inflammatory resorption?
It raises the pH and so reduces the attachment and growth of human PDL ligament fibroblasts (Attachment and growth decrease >7.8 pH) this favours bone healing response leading to ankylosis and replacement resorption
Induced necrosis of all cells (both resorbing and reparative cells)
This favours ankylosis and replacement resorption
Ca(OH)2 effect summary:
Calcium hydroxide almost entirely eliminated
established inflammatory resorption elicited
by bacterial contamination in the replanted
teeth with a necrotic PDL
BUT the resultant healing was characterised
by ankylosis which gradually developed into
replacement resorption
Why is Ca(OH)2 normally used?
Mainly because of its anti-bacterial activity
Stimulates hard tissue formation
Helps dissolve necrotic tissue
Detoxifies bacterial endotoxin (LPS)
Does biomechanical preparation and irrigation inactivate LPS?
No, Ca(OH)2 is necessary to inactivate LPS
What are the management strategies for external inflammatory resorption?
Preventative approach: After injuries where pulp necrosis and infection
PLUS root surface and PDL damage are likely
Interceptive approach: When inflammatory resorption is already present
What are the aims of prevention of external inflammatory resorption?
Reduce PDL inflammation
Inhibit clastic cells
Stop bacteria entering the
root canal
Kill any bacteria that
entered the canal during
the injury
What are the aims of interception of external inflammatory resorption?
Reduce PDL inflammation
Inhibit clastic cells
Kill all bacteria that are
already in the root canal
Encourage healing with
hard tissue
When does PDL inflammation start?
IMMEDIATELY
As soon as the injury has occurred
What are the 2 principles of preventive management of external inflammatory resorption?
- Immediate systemic antibiotics for 1 week (penicillin and tetracycline)
- Immediate pulp removal and placement
of a CS-AB intracanal medicament (CS-AB dressing)
What is the systemic immediate drug for prevention of external inflammatory resorption?
Tetracycline such as doxycycline
What are the steps in preventive management of external inflammatory resorption in mature teeth?
Remove the pulp
Prepare canal if time is available
Place CS-AB dressing
After 6 weeks:
Redress canal with CS-AB paste
Take PA.
After further 2 months:
Take PA radiograph (If no resorption complete RCF)
When taking the PA radiograph after 6 weeks what do we look at?
If resorption is present: Redress canal with CS-AB paste
If no resorption present: Place new dressing using 50:50 CS-AB + Ca(OH)2
What are the steps in preventive management of external inflammatory resorption in immature teeth?
Immediate systemic ABs + pulp removal after replanting/repositioning and splinting.
After 4 weeks:
Redress canal with CS-AB
After another 4 weeks:
Redress canal with CS-AB
After another 4 weeks:
Take PA:
If resorption present redress canal with CS-AB
If no resorption present place new 50:50 dressing CS-AB + Ca(OH)2
After 2 months:
Take PA radiograph:
If no resorption: An apical tissue barrier is desirable (re-dress canal with Ca(OH)2 paste, change Ca(OH)2 dressing every 3 months until hard tissue is repaired
Complete RCF
When should clinical and radiograph reviews be done?
Clinical and radiographic reviews are essential at 6 months after the RCF is completed then every 3-4 years for as long as possible
Why is it important for treatment to be immediate?
IMMEDIATE Endodontic treatment (when indicated)
also avoids problems of facial swelling, discomfort,
apprehension, etc that are associated with delayed
treatment - even if only delayed for a few days
What are the differences between the preventive management and the interceptive management?
2 main differences:
Systemic ABs are not indicated (they will not stop the resorption) only prescribe if the patient presents with acute apical abscess with systemic signs or facial cellulitis/spreading infection
Long term Ca(OH)2 intercanal dressings will be required to stimulate hard tissue repair since hard tissue has been lost.
What are the steps to the interceptive management of external inflammatory resorption?
Commence root canal treatment
Remove the cause(s) of the disease: i.e. remove the caries, cracks, old restorations
Prepare & disinfect the root canal system: i.e. WL, instrumentation, irrigants, etc.
Place a CS-AB paste dressing
After 6 weeks - Re-dress canal with the CS-AB paste
After another 6 weeks take a PA radiograph. If resorption present CS-AB. If no further resorption present CS-AB + Ca(OH)2 50:50
After a further 2 months
Take PA radiograph
If repair evident / no further resorption: Dress canal with Ca(OH)2
Every 3 moths after change the Ca(OH)2 dressing until there is hard tissue repair/apexification
After 9 - 12 months, Take PA radiograph to assess healing
When hard tissue repair is evident complete the RCF
