Lining Materials Flashcards
What are examples of a liner?
Setting calcium hydroxide
GIC
RMGIC
ZOE
What is the purpose of a liner?
Protect the pulp against:
- chemical stimuli (unreacted monomer for example)
- thermal stimuli (during reaction if exothermic or during curing)
- protects from bacteria and endotoxins
- promote pulpal healing through irritating odontoblasts which leads to formation of tertiary dentine
What is setting calcium hydroxide
This is a liner material that is bactericidal and protects the pulp via irritating odontoblast layer which leads to necrosis and formation of tertiary dentine as protective mechanism
What is setting calcium hydroxide composed of?
Base (calcium hydroxide, filler)
Catalyst (butylene glycol disalicylate - reactive element, filler)
REACTION IS CHELATION RXN THAT OCCURS BETWEEN ZINC OXIDE AND REACTIVE ELEMENT FORMING ALKALINE LINER
What is issue with setting calcium hydroxide?
unstable and soluble in wet dentine
What is ZOE?
Zinc oxide eugenol that is composed of
ACID = Eugenol
BASE = Zinc Oxide
An acid base chelation reaction occurs to form a zinc eugenolate matrix
What is ZOE used for?
Root canal sealer
Liner
What are some properties of ZOE?
Adequate Wirkung time
quick setting time
Low thermal conductivity
radioqpaque
low strength
What cant be used under composite resin?
ZOE as eugenol is constantly released from ZOE which can interfere with resin set - softens and discolours the resin
What is resin modified ZOE?
This is where resin is added to the ZOE - it doesn’t take part in the reaction but it increases strength of material
Wha liner should we use in dentine cavities?
RMGIC
What liner should we use when close to pulp?
Setting calcium hydroxide
followed by RMGIC
