root resorption Flashcards
definition
the non-bacterial destruction of the dental hard and soft tissue due to the interaction of clastic cells
stimulation of osteoclast activity
signals can up/down regulate osteoclast activity
- RANKL promotes development/ formation so upregulates ( by binding to receptor RANK on osteoclast)
- OPG inhibits osteoclast development - down regulates ( by binding to RANKL)
RANKL stimulation
- parathyroid hormone, integrin B3 and IL-1B (interleukin)
- bacterial lipopolysaccharides
- trauma (physical, chemical)
- chronic inflammation
apart from trauma can be hard to identify cause
the cell
multinucleate giant cells
e.g. osteoclast - when attached to dentine sometimes called dentinoclast as attacking dentine
highly specific and effective
key features
- v motile
- ruffled border (large SA so can resorb v quickly)
- in contact with dentine
aspects of OC/dentinoclast
sit in Howships lacunae intracellular vesicles release proteolytic enzymes ruffled border integrins to attach
surfaces of tooth which act to prevent resorption
PDL (external)
- e.g. trauma - PDL necrosis = intimate contact between OCs and dentine
cementum (external)
- particularly the non-mineralised layer
predentine (internal)
- non-collagenous component, closest to pulp
but when damaged the resorption process can begin
types of internal resorption
inflammatory
replacement
types of external resorption
inflammatory
replacement
cervical
surface
EO exam - smile line
if there is a consideration for endo microsurgery
- post-surgical recession or scarring (aesthetics)
IO exam - tooth in question
coronal integrity of remaining tooth and Rx quality colour PD pocketing sinus inc location in relation to mucogingival jct swelling apical tenderness TTP mobility occlusal contact in ICP and guidance integrity of adjacent teeth sensitivity test
IO exam - coronal integrity of remaining tooth and Rx quality
can tooth be predictably restored after tx?
IO exam - colour
pink spot - in external cervical resorption
IO exam - PD pocketing
with a PCP12 probe both horizontally and vertically (BPE not small enough)
- is there a PD communication with the resorption?
IO exam - sinus inc location in relation to mucogingival jct
has the internal resorption perforated the RC?
IO exam - swelling
associated with periradicular disease
IO exam - apical tenderness
associated with PR disease
IO exam - TTP
a test of the PDL not necessarily PR disease
IO exam - mobility
no physiological mobility and high pitched percussion (external replacements resorption)
IO exam - occlusal contact in ICP and guidance
is the tooth in fct and prudent to retain?
IO exam - integrity of adjacent teeth
alternative replacement options e.g. bridge
IO exam - sensitivity test
pulp response
all positive except external inflammatory resorption
radiographic examination
absolute minimum is an up to date PA subsequent to any tx
- need 2 from different angles for parallax (SLOB)
- 30 degree mesial or distal beam shift
CBCT (not always needed)
radiographic appearance - internal resorption
ballooning out of canal - parallel lines of root canal disappear
parallax - doesn’t move - stays centred in canal
radiographic appearance - external resorption
can just make out parallel lines of RC system - superimposed on resorption
parallax - appears to change position
internal inflammatory resorption - prevalence
<1%
internal inflammatory resorption - vague clinical findings & radiograph findings
- no PD pocketing unless lesion has perforated root surface
- mostly found incidentally on radiograph
- radiolucency central in canal, not move with parallax
- ballooning of canal
- tramlines of RC indistinct
- Root surface intace
internal inflammatory resorption - pathogenesis
coronal pulp is necrotic
lesion includes inflammatory and vascular tissue - if perforated will communicate with PDL
apical pulp is vital (need vital pulp to allow it to progress and keep nibbling)
lesion will continue to progress until apical pulp goes completely necrotic - until PA radiolucency - indicates complete necrosis
- RR likely stopped by this point
can happen in any part of root
- in apical region a consequence can be root perforation
internal inflammatory resorption - likely cause
trauma
Internal inflammatory resorption more common in M/F?
Male
internal inflammatory resorption - tx
orthograde endo only
- active irrigation and disinfection,
- intervisit medicament (disperse and agitate CaOH e.g. endoactivator) - won’t be able to mechanically clear all the D of OCs
can be hard to find apical canal beyond lesion- ns CaOH for 4-6 weeks
- thermal obturation e.g. warm vertical compaction
possible haemorrhage
internal replacement resorption - diagnosis
no clinical indications
incidental finding radiographically - trabecular pattern in pulp - ossified
Internal replacement resorption radiographic findings
- irregular enlargement of the pulp space
- bone-like and extends into the dentin towards the cementum
-resemble cancellous bone (trabecular)
internal replacement resorption - tx
RCT nearly impossible: - ossified - thin root dentine in walls - perforation risk if can't RCT often let it run course then when symptomatic look at replacement options
external surface resorption - clinical features
can be unrestored
increased physiological mobility
+ve to sensibility tests
external surface resorption - radiographic features
PDL space and lamina dura intact
no obvious periapical radiolucency
external surface resorption - aetiology
- Damage to PDL which subsequently heals.
- Non-progressive
orthodontics
- 90% of teeth have some form of ESR
- 2-5% severe ESR
- 15% moderate
- usually teeth for anchorage are the worst affected ( max canine/ lats)
ectopic teeth - pressure from erupting tooth
pathological lesions - pressure from adjacent pathological lesion e.g. odontogenic keratocyst
idiopathic
external surface resorption - tx
pulp healthy - DON’T RCT
remove the source to stop the resorption
splint if mobile
external inflammatory resorption - clinical findings
usually restored
no PD pocketing, colour normal
may have sinus, swelling, apical tenderness, TTP
mobility may be increased depending on extent
sensitivity negative - pulp is necrotic
external inflammatory resorption - radiographic findings
- moth-eaten appearance
- loss of lamina dura, PDL sapce
- radiolucency in the adjacent alveolar bone
- periapical radiolucency
- indistinct root surface
- intact RC tramlines
external inflammatory resorption - aetiology
- progressive
- pulp is necrotic - bacterial or dental trauma in origin
- periapical inflammatory lesion (damage to PDL initially ) precipitates the resorption process
- Propagated by RC toxins reaching external root surface - via dentinal tubules
- majority (81%) of teeth with periapical lesions will have microscopic areas of RR
- only 7% of these are detectable radiographically
external inflammatory resorption - tx
remove the cause of the inflammation
usually orthograde endo (re) tx, possibly surgical endo, or extraction
if apex significantly resorbed may not be able to control GP - need to alter technique
arrests RR
only external RR that benefits from endo
External cervical resorption classification 2 types
- Heithersay 1999
- Patel 2016
external cervical resorption - clinical findings
can be unrestored
- pink spot on crown
- PD pocketing: yes if extensive and profuse BOP
- probe may drop into a hard cavity when you probe margin
- can misdiagnose as caries - but will be hard to probe - lesion has good blood supply - don’t always see e.g. if small or in particular position may not see it until get to a critical stage
= won’t always have these S and S
normal or no mobility
positive to sensitivity testing
external cervical resorption - radiographic findings
radiolucency at level of CEJ
can still see parallel RC lines, changes in position with parallax
CBCT can show apical coronal spread
resorption radiolucency is superimposed on the pulp
external cervical resorption - aetiology
- orthodontics
-
trauma - avulsion and luxation
- don’t traumatise CEJ with forceps when repositioning traumatised tooth - historical non-vital whitening when heat was applied
- vvv rare with modern bleaching - wind instruments
- viral infection (from cats)
- systemic disturbance (thyroid)
Name of layer in predentine that protects pulp from resorption
Pericanalar Resorption Resistant Sheet (PRRS)
external cervical resorption - tx options
- monitor
(the resorption will v likely continue - significant number are progressive) - extraction and prosthetic replacement
- surgical repair
-
leave root in situ
(preserve ST and bone) - surgical repair and orthograde endo
- internal repair and orthograde endo
(if can’t access surgically)
need clean and frosted dentine otherwise RR will continue - keep going with chemical disinfection
external cervical resorption - tx options - surgical repair
flap to expose
NaOCl - coagulation necrosis of resorptive cells
can’t get rid of all lacunae with handpiece as can’t see them and would remove too much tooth
external cervical resorption - tx options - surgical repair and orthograde endo
1/3 pulp exposed/after pulp becomes necrotic
do endo first to avoid periapical radiolucency
external cervical/replacement resorption - healing?
v rarely does it cease and allow healing lesion has a trabecular pattern bone rather than ST the PDL is present no tx
which tooth more at risk of external cervical resorption
max canine > max incisor > mand molar
external replacement resorption - clinical findings
- infraoccluded
- possibly erythematous
- high-pitched note
- ankylosed - no physiologicla mobility
external replacement resorption - radiographic findings
loss of obvious PDL
cotton wool appearance
root surface replaced by trabecular pattern - bone
affects a lot of root surface
external replacement resorption - aetiology
trauma
- significant injuries to there periodontium such that bone (OCs) are then in contact with external root dentine to begin resorption
e. g. avulsion or lateral luxation - bone cells faster than PDL fibroblasts
- bone directly fused to dentine
- Progressive.
- Tooth gradually resorbed as it is now part of bone remodelling.
external replacement resorption - tx options
- decoronation : growing pt
- monitor + Incisal comp build up : non growing pt
- endo will not stop resorption - no RCT
external replacement resorption - tx options - decoronation
if infra occlusion is >1mm in a growing pt
remove crown to alveolar level and allow root to resorb - root replaced by bone
this preserves bone volume
adjacent teeth and periodontium develop normally
tooth replacement with denture or RBB
external replacement resorption - why do you need to intervene early in a growing pt?
alveolus growing around it
- avoid further recession of gingival margin - infra-occlusion
- need height of bone for implant
- also adjacent teeth tip into prosthetic space
Which resorption to use :
primary tx strategies for resorption - orthograde endo
external inflammatory
internal inflammatory
primary tx strategies for resorption - surgical endo
external cervical
primary tx strategies for resorption - no endo
external surface
external replacement
ECR - Heithersay 1999 classification
- 2 dimensional
- 1
- 2 : little or no root dentine involvement
- 3: coronal 1/3 of root dentine
- 4: Beyond coronal 1/3 of root dentine
ECR - Patel 2016 classification
- 3 dimensional
- 3 parts : apico-coronal / circumferential/ pulp involvement
- eg. 2Bp
