root resorption Flashcards
What is root resorption?
The non-bacterial destruction of the dental hard and soft tissue due to the interaction of clastic cells
What are the key features of root resorption?
Very mobile teeth
Ruffled border - good resorbing hard tissue
In contact with dentine
What can cause RANKL stimulation?
PTH, B3 and interleukin - 1B
Bacterial lipopolysaccharides
Trauma (physical and chemical)
Chronic inflammation
What do RANKL and OPG do?
RANKL stimulates bone resorption
OPG inhibits RANKL, inhibiting the resorption of bone
What surfaces are affected by root resorption and why are they important in root resorption?
PDL - divides bone from root
Cementum - particularly non-mineralised layer
Pre-dentine (non-collagenous component)
These act to prevent resorption, however when damaged resorption can occur
What are the different types of internal root resorption?
Inflammatory
Replacement
What are the different types of external root resorption?
Inflammatory
Replacement
Cervical
Surface
What radiographic examination should be carried out for root resorption?
2 angles - 30ºmesial or distal beam shift
CBCT
How does internal resorption look radiographically?
Lose the parallel lines of the root canal as it expands
How does external root resorption look radiographically?
Nothing to do with root canal system
Area superimposed over pulp but will still be able to see the lines of the root canals
What is needed for resorption to occur?
A blood supply
Describe internal inflammatory root resorption
An incidental finding
Positive to sensibility testing
Centred on canal in radiographs and doesn’t move with beam shift
Generally doesn’t have a periapical radiolucency
Explain the pathogenesis of internal inflammatory resorption
Coronal pulp is necrotic
Lesions include inflammatory and vascular tissue - if perforated will communicate with the PDL
Apical pulp is vital
Lesion will continue to progress until apical pulp goes completely necrotic
How is internal inflammatory resorption treated?
Orthograde endodontics only
Describe internal replacement resorption
Pulp has expanded and is radiopaque radiographically
Positive to sensibility testing
Describe external surface resorption
Positive to sensibility testing
Normal to examination
Increased physiological mobility
PDL is intact
No periapical pathology
Lesion may have a trabecular pattern - has been healed with bone
Explain the aetiology of external surface resorption
Orthodontics - affects 90% of teeth, 2-5% have severe, 15% moderate, usually the teeth for anchorage are worst affected
Ectopic teeth - pressure from erupting teeth
Pathological lesions - pressure from adjacent pathological lesion
Idiopathic
How is external surface resorption treated
Remove the source to stop the progression
Pulp is healthy so no endodontic treatment
Splint teeth if mobile
Describe external inflammatory resorption
Negative to sensibility testing - pulp is necrotic
Periapical radiolucency present
May be a history of trauma
Tooth usually previously restored
Explain the aetiology of external inflammatory resorption
Necrotic pulp - bacterial or dental trauma in origin
Periapical inflammatory lesion precipitates the resorption process
Majority of teeth (81%) of teeth with periapical lesions will have microscopic areas of root resorption - only 7% of these detectable on radiographs
How is external inflammatory resorption treated?
Usually orthograde endodontic re-treatment
Possibly surgical endodontics or extraction
Describe external replacement resorption
Positive to sensibility testing
High pitch percussion note - due to no PDL
Pulp appears normal
No obvious periapical radiolucency
No obvious PDL
Root surface replaced by bone
Endodontic treatment has no impact on this
Commonly manifests as infra-occlusion
Explain the aetiology of external replacement resorption
Trauma - significant injuries to the periodontium such that bone (osteoclasts) is then in contact with external root dentine to begin resorption
Eg - avulsion or lateral luxation
How is external replacement resorption treated?
Monitor if patient has stopped growing
Because of infra-occlusion, can add composite incisally
No endo - will not stop the resorption
Decoronation
