1 - Resorption Flashcards
Define root resorption.
Non-bacterial destruction of dental hard and soft tissue due to the interaction of clastic cells
What cells initiate root resorption?
- osteoclast by definition, although referred to as dentinoclast when on dentine
- originate from multinucleated giant cells
What are the features of dentinoclasts?
- motile (can move from bone to dentine root surface when PDL is not present)
- ruffled border that releases proteolytic enzymes
What stimulates dentinoclasts?
RANKL
What up-regulates RANKL?
Unknown although below answers are thought possible
- parathyroid hormone
- bacterial lipopolysaccharides
- trauma
- chronic inflammation
Give an examples of a RANKL inhibitor.
Denosumab
What trauma are most likely to result in root resorption?
- avulsion
- lateral luxation
- intrusion
What surfaces protect against root resorption?
- PDL
- cementum (non mineralised layer)
- predentine (non-collagenous component)
How is root resorption classified?
- internal
- external
What are the types of internal root resorption?
- inflammatory
- replacement
What are the types of external root resorption?
- inflammatory
- replacement
- cervical
- surface
How do you differentiate between external and internal resorption on a radiograph?
- external, tramlines are still visible, parallax applies
- internal, bulbous deformity in tramlines, parallax does not apply
Describe the clinical findings in internal inflammatory resorption.
- no pocketing unless root surface perforated
- no sinus unless periradicular disease
- no TTP
- no mobility
- positive response to sensibility
Describe the radiographic findings in internal inflammatory resorption.
- centred in canal, tramlines move with bulbosity
- does not move with beam shift
- usually no PA radiolucency
Describe the pathogenesis of internal inflammatory resorption.
- coronal pulp is necrotic, apical pulp is vital
- lesion includes inflammatory and vascular tissue and will communicate with PDL if perforation present
- lesion progresses until apical pulp becomes necrotic and blood supply is lost
How do you manage internal inflammatory resorption?
- orthograde endodontics only
- CaOH used as intervisit medicament due to caustic properties that chemically disinfect areas that are unable to be instrumented due to morphology of resorption
Describe the radiographic findings in internal replacement resorption.
- incidental finding
- pulp is replaced by bone/PDL/cementum and appears radiopaque with trabecular pattern
Describe the clinical findings in internal replacement resorption.
No abnormal clinical findings
How do you manage internal replacement resorption?
- no treatment until symptomatic
- if symptomatic or fractures, requires tooth replacement option
- RCT very unpredictable
Describe the clinical findings in external surface resorption.
- increased physiological mobility
- positive response to sensibility
Describe the radiographic findings in external surface resorption.
- roots appear short
- PDL intact
- pulp normal
- root can appear with trabecular pattern after healing of previous surface resorption
How do you manage external surface resorption?
- remove source of resorption
- endodontics ineffective
- splint teeth if mobile
- DWP risk associated with perio, as less supporting root structure and tooth loss more likely
Describe the pathogenesis of external surface resorption.
- orthodontics, as teeth move through bone the root is resorbed away, teeth used for anchorage are worst affected
- ectopic teeth
- cysts
- idiopathic
What is the percentage of teeth experience external surface resorption?
- 90% experience
- 2-5% have severe
Describe the clinical findings in external inflammatory resorption.
- usually previously restored teeth
- may have increased mobility
- negative to sensibility testing (pulp necrotic)
- possible sinus, swelling, TTP or apical tenderness
Describe the radiographic findings in external inflammatory resorption.
- restoration can be close to pulp horn
- apical area associated with resorption
Describe the pathogenesis of external inflammatory resorption.
- inflammatory reaction
- necrotic pulp drives resorptive process
- bacterial or dental trauma origin
- PA inflammatory lesion precipitates resorption process
How do you manage external inflammatory resorption?
- remove cause of inflammation
- orthograde endodontics (or re-RCT)
- XLA
- if lack of apical stop, refer
Describe the clinical findings in external replacement resorption.
- infraoccluded
- no TTP, but high pitch percussion note
- NO physiological mobility
- positive to sensibility
Describe the radiographic findings in external replacement resorption.
- no PA radiolucency
- no PDL
- pulp normal
Describe the pathogenesis of external replacement resorption.
- trauma in which significant injury to PDL and allows osteoclasts to contact root dentine
- most commonly avulsion and lateral luxation
How do you manage external replacement resorption?
- decoronate if infraocclusion >1mm in growing patient
- remove crown to alveolar level and allow root to resorb to preserve bone volume and tooth replacement with denture or RBB
- camouflage with composite if smile line suitable
Describe the clinical findings in external cervical resorption.
- if extensive, pocketing and +++ BOP
- gingiva can be inflamed
- pink spot lesion
- normal mobility
- positive to sensibility
Describe the radiographic findings in external cervical resorption.
- radiolucent area on root surface
- tramlines intact
- parallax applies with cone shift
- CBCT shows pulp spared
Describe the spread of external cervical resorption.
- regular invasive pattern
- predentine protects pulp
How do you manage external cervical resorption?
- can monitor although likely resorption will continue
- decoronate with hypochlorite to disinfect and destroy resorptive cells
- XLA and prosthetic replacement
- internal repair and orthograde endodontics (specialist)
How is external cervical resorption classified?
Apico-coronal
1 - crestal
2 - coronal 1/3
3 - middle 1/3
4 - apical 1/3
Circumferential
1/4
1/2
3/4
>3/4
What are the risk factors for external cervical resorption?
- orthodontics
- trauma (avulsion/luxation)
- historical non-vital whitening with heat
- wind instruments
- viral infection
- systemic disturbance eg thyroid
