CAVITY LINERS AND BASES Flashcards
thin layers of material used primarily to provide a barrier to protect the dentin from residual reactants diffusing out of a restoration and/or fluids which may penetrate leaky tooth-restoration interface
LINERS
LINERS FUNCTIONS [4]
→ chemical insulator
→ stimulate formation of tertiary dentin
→ sterilize residual carious dentin with its anti-bacterial action
→ direct and indirect pulp capping
insulating materials that provide thermal protection for the pulp and to supplement mechanical support for the restoration by distributing local stresses from the restoration across the underlying dentin surface
BASES
BASES FUNCTIONS [3]
→ thermal insulation
→ mechanical insulation
→ provides strong support during insertion of permanent
restorations
MATERIALS USED AS CAVITY LINERS AND BASES [6]
→ Zinc Oxide Eugenol Cement
→ Calcium Hydroxide
→ Zinc Phosphate Cement
→ Polycarboxylate Cement
→ Varnishes
→ Glass Ionomer Cement (GI)
zinc oxide
A. Powder
B. Liquid
A
eugenol
A. Powder
B. Liquid
B
setting time acceleration:
ZINC OXIDE EUGENOL CEMENT
o increase powder-liquid ratio
o increase temperature and humidity
o adding water to the mix after mixing is complete and
seated in the preparation
T/ F
ZINC OXIDE EUGENOL CEMENT increase pressure, movement, and time during mixing
T
T/ F
ZINC OXIDE EUGENOL CEMENT
Has least amount of shrinkage
And least irritating
T
T/ F
ZINC OXIDE EUGENOL CEMENT thermal insulation at 0.25 mm thickness
T
T/ F
ZINC OXIDE EUGENOL CEMENT cannot be used as a base for composite because it can inhibit polymerization
T
T/ F
CALCIUM HYDROXIDE has 2 paste system, the Acidic Paste and Basic Paste
T
T/ F
CALCIUM HYDROXIDE packing factor is high; mass is porous
False
(packing factor is LOW; mass is porous)
used as a subbase
CALCIUM HYDROXIDE
0.5 mm-1.0 mm thickness is sufficient to treat a near or actual pulp exposure
CALCIUM HYDROXIDE
T/ F
CALCIUM HYDROXIDE
pulp tissue in contact with CaOH will undergo coagulation
(necrosis)
T
alkyl salicylate + filler
A. Acidic Paste
B. Basic Paste
A
calcium hydroxide
A. Acidic Paste
B. Basic Paste
B
promotes secondary dentin formation
CALCIUM HYDROXIDE
resinous solution in which calcium hydroxide and zinc oxide are suspended
FORMS OF CAVITY LINER
aqueous solution of calcium hydroxide in methyl cellulose or hydroxyethyl cellulose base
FORMS OF CAVITY LINER
resinous solution that is light-activated
FORMS OF CAVITY LINER
ZINC PHOSPHATE CEMENT Powder Form
zinc oxide with magnesium oxide + tribismuth oxide + silicon dioxide
ZINC PHOSPHATE CEMENT Liquid form
45-55% orthophosphoric acid