ENDO root resorption Flashcards
what is the definition of root resorption?
a physiological or pathological event mainly occurring due to the action of activated clast cells
what is root resorption characterised by?
the transitory or progressive loss of cementum or cementum/ dentine
what is the onset of root resorption associated with?
significant necrosis of cementoblasts and/or injury to the PDL
what are the 2 phases required to cause root resorption?
injury and stimulation
what types of injury cause root resorption?
mechanical
infection of root canal or PDL
chemical
what types of mechanical injury causes root resorption?
trauma
surgical procedures
excessive pressure (impacted teeth, cyst tumours, ortho tx)
what type of chemical injury causes root resorption?
bleaching agents (30% hydrogen peroxide)
what type of stimulation causes root resorption?
infection
pressure
transient resorption (without a constant stimulus the process if self limiting)
lost systemic and endocrine disease which may cause root resorption?
hypo and hyperthyroidism
calcinosis
gauchers syndrome
turner syndrome
pagets disease
herpes zoster
what type of cells colonise damaged surfaces and initiate the resorptive process?
odontoclasts/ osteoclasts
what are howships lacunae?
depressions of odontoclasts/ osetoclasts
what cells regulate the physiological and pathological resorption of mineralised tissue?
receptor-ligand system RNAKL/RANK/OPG - part of the TNF family
what cells carry the RANK receptor?
osteoclast precursor cells and dendritic cells
what induces the fusion of osteoclast precursor cells into multinucleated cells?
binding of RANKL to RANK
what is the most common cause of resorption?
pulp infection
what are causes of resorption, based on stimulation factors?
pulp infection
PDL infection
ortho pressure
ankyloses
tumour
impacted pressure
what does EIR affect?
the external root surface
what usually causes EIR?
trauma - intrusion, lateral luxation and avulsion