Root Resorption Flashcards
What is root resorption?
Non-bacterial destruction of the dental hard and soft tissue due to the interaction of clastic cells
What are the key features of Osteo/dentinoclasts?
- Very motile
- Ruffled boarder- good at getting into lacunae
- In contact with dentine- large surface area
- Integrins
- Intracellular vesicles
What causes RANKL stimulation? (results in bone resorption)
- Parathyroid hormone, B3 and interleukin -1B
- Bacterial lipopolysaccharides
- Trauma (physical, chemical)
- Chronic inflammation
How are dentinoclasts influenced by OPG and RANKL?
- Up regulated by RANKL
- Down regulated by OPG
What are the surfaces that protect a tooth from resorption?
PDL
Cementum
Predentine- protects from internal resorption
-> if these are intact then dentino/osteoclast cannot come into contact with dentine
What are the types of root resorption?
Internal
-> inflammatory
-> replacement
External
-> surface
-> inflammatory
-> replacement
-> cervical
What are the aspects to assess on examination in cases with suspected root resorption and why? pt 1
Smile line - if there is a consideration for Endodontic Microsurgery
-> aesthetic risk from scarring/recession
Coronal integrity of remaining tooth and restoration quality
-> can tooth be restored predictably
Colour
-> Pink spots
Periodontal pocketing with a PCP12 probe both vertically and horizontally
-> Communication between periodontium and resorption (6PPC for tooth)
Sinus including location in relation to mucogingival junction
-> has internal resorption perforated the canal
What are the aspects to assess on examination in cases with suspected root resorption and why? pt 2
Swelling/Apical tenderness
-> Associated with periradicular disease
Tenderness to percussion
-> Checking PA tissue
Mobility
Occlusal contact in ICP and guidance
-> Is the tooth functional and prudent to retain
Integrity of adjacent teeth
-> alternative replacement options like bridge
Sensitivity test
-> check for pulp response
What radiographs are taken for root resorption?
PA
-> Parallax (30 degrees M/D beam shift)
-> helps determine whether buccal or lingual or int/external (if resorption moves- EXTERNAL)
CBCT
How does internal and external inflammatory resorption appear on radiographs?
Internal- balloons out from internal aspect of canal
-> Parallel lines of RCS have been lost
External- superimposition of resorption but can still see tramlines of the root canals
What are the clinical findings with internal inflammatory resorption? (Very little signs and symptoms)
Coronal integrity- may be unrestored
Perio pocketing- nil unless lesion has perforated root surface
Colour- normal
No sinus- unless PA disease
No Swelling, apical tenderness TTP
Normal mobility
Positive to sensibility tests (mostly)
How does internal inflammatory resorption appear radiographically?
Centred in canal, doesn’t move with beam shift
What is the pathogenesis of internal inflammatory resorption?
Coronal pulp is necrotic
Lesion includes inflammatory and vascular tissue - if perforated will communicate with PDL
Apical pulp is vital
Lesion will continue to progress until apical pulp goes completely necrotic
What does a periapical lesion in a tooth with suspected internal inflammatory resorption suggest?
PA radiolucency suggests loss of vitality of the tooth (resorption has topped)
What is the issue with treatment of internal inflammatory resorption?
Possible haemorrhage
How is internal inflammatory resorption treated?
Active irrigation- M activator
Intervisit medicament- Ca/Iodoform paste (esp if not happy with disinfection)
Thermal obturation
-> seal below CEJ with flowable and composite (if unrestored)
What colour is necrotic pulp?
Black
What are the clinical findings for Internal Replacement Resorption?
May be unrestored
NO:
Perio pocketing, colour change, sinus, swelling, apical tenderness, TTP, mobility
Positive to sensibility tests
How does internal replacement resorption appear on radiograph?
- Pulp is enlarged with radiopacities (pulp is being replaced by mineralised mixed hard tissue- dentine, cementum, bone, PDL)
- RCS has expanded
How is internal replacement resorption managed?
Chances of instrument fracture are high- very difficult to negotiate pulp chamber
-> Accept, monitor, plan for definitive restoration
What are the features of external surface resorption?
Patient presents with mobile teeth
PDL remains intact, No PA radiolucency
Pulp is vital
What are the causes of External surface resorption?
Ortho
Ectopic canines/teeth- resorb roots of adjacent teeth (resorption pattern follows shape of ectopic tooth)
Ameloblastoma (refer to OMFS)- suggest which teeth need extracted
Idiopathic/Incidental
Occurs in deciduous teeth as permanent successor erupts
What does a trabecular pattern developing in the area of resorption suggest?
Healing
What are the incidences of ESR in ortho patients?
Occurs in 90%
-> 15% have moderate
-> 2-5 % have sever
Teeth used for anchorage are worst affected
How is ESR treated?
The PULP is HEALTHY - Endodontic treatment will NOT have any effect REMOVE the SOURCE to stop the resportion
-> splint if mobile
What are the clinical findings in External inflammatory resorption?
Usually restored teeth
No pocketing
No colour change
Possible- sinus, swelling, apical tenderness, TTP
Mobility may be increased
Negative to sensibility testing as pulp is necrotic
What causes External Inflammatory resorption?
Necrotic pulp - bacterial or dental trauma in origin
-> periapical inflammatory lesion precipitates the resorption process
Restorations encroaching on pulp horns
Inflammation from adjacent teeth
What % of teeth with PA radiolucency have External inflammatory resorption?
81% of teeth with PA radiolucency will have microscopic areas of EIR
Uncommon to be very large size
7% seen on radiographs
How is EIR treated?
Remove cause of inflammation (necrotic pulp)
-> Usually orthograde RCT (re)
-> possibly surgical endodontics or extraction
What is the issue with RCT in teeth with EIR?
Apical constriction may not be present
Apical control may not be possible
What are the clinical findings for External Replacement Resorption?
Can occur in unrestored tooth
Infra-occlusion (if patient still growing)
Erythematous gingivae
No colour change, swelling, apical tenderness, sinus
High pitched noise on percussion (if 20% of root surface affected)
No physiological mobility
Positive to sensibility testing
What happens to root in External replacement resorption?
Root disappears and becomes filled in with bone
-> Lost PDL
What commonly causes External replacement resorption?
Trauma - significant injuries to the periodontium such that bone (osteoclasts) is then in contact with external root dentine to begin resorption
-> Avulsion
-> Intrusion/lateral luxation injury
How are infra occluded teeth which have occurred due to ERR treated in growing patients? Why?
If infraocclusion is more than 1mm in a growing patient
-> Remove crown to alveolar level and allow root to resorb
-> preserves bone volume
-> Adjacent teeth and periodontium develop normally
-> Tooth replacement with denture or RBB
How are infra occluded teeth which have occurred due to ERR treated in non-growing patients?
Add composite to restore to normal height
What are the restorative issues with infra-occluded teeth?
- Teeth tip in- cannot replace with restoration of same shape
- Significant hard and soft tissue defect- asymmetrical implant crown
Why is RCT not done for ERR?
Resorption continues after endodontic treatment (will not stop it)
-> Difficult to remove GP from bone when replacing with implants
Do not do endo for this issue
What should be done with canals in avulsed teeth in adults?
Do not obturate, fill with CaOH instead of GP (this will resorb with tooth)
What are the clinical findings in teeth with external cervical resorption? (high incidence, high variation between cases)
Can be unrestored
Gingival inflammation- profuse BOP
Pink spots
Subgingival cavities- may give transparent look if underlying cavity
Pus
Usually normal mobility
-> Infra-occlusion may occur- no mobility
Positive to sensibility testing
How does ECR appear radiographically?
Apple core shape radiographically- from level of CEJ (still see tramlines too)
What additional imaging can be helpful for ECR?
CBCT
What are the pico-coronal classifications of ECR?
▸ 1. crestal
▸ 2. coronal 1/3
▸ 3. middle 1/3
▸ 4. apical 1/3
What are the circumferential classifications of ECR?
1/4
1/2
3/4
More than 3/4
What are the risks for ECR?
Orthodontics
Trauma - avulsion and luxation
Historical non vital whitening when heat was applied
Wind instruments
Viral infection
Systemic disturbance - thyroid
How does ECR appear histologically?
Irregular front of resorption
-> Predentine remains intact- protects pulp (resorption goes around- pulp not involved)
What can be done to remove areas of ECR?
Hypochlorite on a micro brush can cause coagulation necrosis and help remove strands of resorptive cells
What are the treatment options for ECR?
Monitor
Extraction and prosthetic replacement
Internal repair with orthograde endo
Why is GIC used for cavities caused by ECR?
- Subgingival- allows moisture control
- Not on occlusal loading
- Good with PDL
How may proximal ECR be treated?
Cannot access surgically
Treated internally like perforation repair
Try to seal resorption of from gingivae
Flowable composite into defect
