lining materials Flashcards
what are the roles of a lining material?
to protect the pulp
Thermal & chemical stimuli
bacteria and endotoxins
how does a liner protect the pulp?
by providing a bacterial barrier and preventing fluid movement down the dentinal tubules
what is thermal conduction produced by?
cutting a cavity
what is the hydrodynamic effect?
when the dentinal tubules are exposed at the pulp causes changes in fluid flow
lining materials should?
have short setting time
have low solubility (non dissolving)
good strength
what are different lining materials?
calcium hydroxide
resin modified glass ionomer cements
zinc oxide eugenol
flowable composite
varnish
bonding agents
what are properties of calcium hydroxide?
‘Dycal’, ‘Hypocal’
secondary dentine formation
indirect direct pulp capping
Some thermal insulating properties
its biocompatible
what are properties of zinc oxide and eugenol?
‘Kalzinol’, ‘Sedanol’
Effective thermal barrier
effective on the pulp – leached eugenol from set material
what is a disadvantage of zinc oxide and eugenol?
it cannot be used under resin based fillings – interferes with polymerisation
properties of glass ionomer ? either traditional mixed or resin modified light cured
‘Chemfil’, ‘Ketac’, ‘Fuji’, Riva
‘Vitrebond’
releases fluoride
Adhesive to enamel and dentine
Biocompatible (not harmful or toxic)
(its water sensitive & its not radiopaque)
properties of flowable composite?
Used as lining under composite fillings
Flow into cavities
Elastic properties may absorb some of the stresses caused by polymerisation shrinkage
properties of cavity varnish?
Seals dentinal tubules
Prevents irritating chemicals found in some materials from entering tubules
properties of bonding agents? Etch, (Prime and Bond)
Provides elastic interface between tooth and restorative materia
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Seals dentinal tubules
Under composite – retains filling and seals dentine
