root resorption Flashcards
root resorption definition
non bacterial destruction of dental hard & soft tissue due to interaction of clastic cells
key features of osteoclast cell (3)
- very mobile
- ruffled border (well adapted to resorb hard tissue)
- in contact with dentine
what induces differentiation to osteoclasts
RANKL - receptor activator NF kappa b ligand
note - OPG (osteoprotegrin) downregulates therefore inhibiting RANKL & so development of osteoclasts
what causes stimulation of RANKL (4)
- parathyroid hormone B3 & interleukin B1
- bacterial lipopolysaccharides
- trauma (physical / chemical)
- chronic inflammation
surfaces involved (3)
- pdl
- cementum
- pre dentine
main categories of resorption & sub categories
- INTERNAL - inflammatory / replacement
- EXTERNAL - inflammatory / replacement / cervical / surface
o/e what probe should be used
PCP12 - as BPE will inhibit examination of pdl
radiographic examination
require 2 angles with 30 degree mesial / distal beam shift ( if shift in what you are looking at strong chance it is external) or CBCT
how does internal resorption appear on radiograph
comes out from middle of root canal so loses parallel lines
how does external resorption appear on radiograph
crucially can see parallel lines of root canal system
presentation of internal inflammatory resorption
positive to sensibility tests, no obvious signs, no pockets unless perforated root surface, no sinus unless peri-radicular disease
radiographically centred in canal, doesn’t move with bean shift & see ballooning of RC i.e. loss of parallel lines
pathogenesis of internal inflammatory resorption
coronal pulp necrotic
apical pulp vital
lesion inc inflammatory & vascular tissue (if perforated will communicate with pd)
lesion will continue to progress until apical pulp goes completely necrotic too
tx of internal inflammatory resorption
orthograde endodontics ONLY
- possible haemorrhage
- active irrigation
- inter visit medicament
- thermal obturation
presentation of internal replacement resorption
no clinical signs
very rare
usually incidental finding
radiographically -> radiopaque expansion of the pulp i.e. replacement element via bone / pdl / cementum (something mineralised) so RCT unpredictable & unlikely to benefit pt
presentation of external surface resorption
clinically normal, only sign may be slightly increased mobility
radiographically -> key thing to note is that PDL IS INTACT
aetiology of external surface resorption (4)
- orthodontics - 90% of teeth have some form of ESR; teeth used for anchorage usually worse 2-5% severe
- ectopic teeth - in lateral incisor which guides in canine
- pathological lesions - pressure from adjacent pathological lesion
- idiopathic
tx of external surface resorption
pulp is healthy so endo tx will not have any effect so must remove source to stop the resorption i.e. remove ortho bracket & splint if mobile
presentation of external inflammatory resorption
find that tooth is usually restored
may have increased mobility depending on extent
sensibility testing is NEGATIVE as pulp necrotic
radiographically -> usually has a PA radiolucency
aetiology of external inflammatory resorption
pulp is necrotic from bacterial or dental trauma in origin
periapical inflammatory lesion precipitates the resorption process
tx of external inflammatory resorption
remove the cause of the inflammation
this is usually via:
orthograde endo tx / re tx
possiibly surgical endo
XLA
note - apical stop can be challenging so consider hydraulic cement rather than GP
presentation of external replacement resorption
historically trauma related
can be unrestored but infra occluded
not TTP but high pitched note
no physiological mobility
radiographically -> pulp appears normal, no PA radiolucency but crucially there is PDL degeneration
aetiology of external replacement resorption
TRAUMA - significant injuries to periodontium such that osteoclasts then in contact with external root dentine to begin resorption e.g. avulsion or lateral luxation
tx of external replacement resorption
DECORONATION
if infraocclusion >1mm in growing pt
remove crown to alveolar lever & allow root to resorb
this preserves bone volume
adjacent teeth & periodontium develop normally
tooth replacement via denture / RBB
if pt fully grown can monitor & add comp incisally if infraoccluded
endo intervention will not stop resorption
consequence of delayed decoronation in external replacement resorption
no pdl so tooth fused to bone so ankylotic percussion note
presentation of external cervical resorption
can be unrestored, perio pocketing if extensive and profuse BoP, notable pink spot, POSITIVE to sensibility testing
pink spot - middle of crown
can have +/- bleeding / erythematous gingivae
radiographically -> radiolucency but still maintains parallel canals
classification of external cervical resorption
apico coronal direction:
1. crestal
2. coronal 1/3
2. middle 1/3
4. apical 1/3
circumferential:
1/4
1/2
3/4
> 3/4
risk factors for developing external cervical resorption (6)
- ortho
- trauma - avulsion & luxation
- historical non vital whitening when heat was applied
- wind instruments
- viral infection
- systemic disturbance i.e. thyroid
tx for external cervical resorption
- monitor - resorption likely to continue
- XLA - + prosthetic replacement
- endo - internal repair & orthograde endo
summary of tx options
orthograde endo = external & internal inflammatory
surgical endo = external cervical
no endo = external replacement & surface
