Lining Materials

Question 0

What is a cavity lining?

Answer 0

A thin coating (<0.5mm) over exposed dentine

Question 1

What is the purpose of a lining material?

Answer 1

Prevents gaps and therefore microleakage.
Acts as a protective barrier from fluids and bacteria.
Makes intimate contact with the tooth to provide good adaption.
Pulpal protection from chemical & thermal stimuli and bacteria & endotoxins.
To calm down inflammation within the pulp and promote healing.

Question 2

What chemical stimuli could harm the pulp of the tooth?

Answer 2

Unreacted chemicals in the filling material

Initial pH of the restoration

Question 3

What thermal stimuli could harm the pulp of the tooth?

Answer 3

Exothermic setting reaction of composite

Heat conducted through metal fillings with high thermal conductivity

Question 4

What should the thermal properties of a lining material be?

Answer 4

Low thermal conductivity
Thermal expansion similar to dentine (11.4 ppm C^-1)
Thermal diffusivity similar to dentine or lower (0.0026cm^2/sec)