6. Root Canal Prepartion

Question 1

What are the aims of obturation?

Answer 1

Entomb (completely surround with the filling material) any residual microorganisms within the root canal system.

Completely seal all anatomical portals of entry/exit to root canal systems

Prevent reinfection of the root canal system by preventing ingress of oral microbes (i.e. coronal leakage from saliva contamination)

Prevent entry of periradicular fluid, which may act as a source of nutrients for any microorganisms inhabiting the root canal system

Question 2

what are the Requirements of an ideal root filling material/

Answer 2

-Biocompatible
-Non-toxic and non-mutagenic
-Easy to handle and have a long working time
-Bactericidal or at least bacteriostatic
-Sterile
-Easy to apply and remove
-Conforms and adapts to the irregular shape of the root canals
-Dimensionally stable on setting
-Insoluble in tissue fluids
-Not stain the tooth
-Stimulates periapical healing
-Radiopaque

Question 3

what is gutta percha?

Answer 3

the “core” material of the root filling.

Question 4

how many forms are there?

Answer 4

Two forms:
α-form – used in injectable Gutta-percha forms

β-form – used in Gutta-percha cones

Question 5

What is the composition of gutta percha?

Answer 5

Zinc Oxide (60-75%)
GP (19-22%)
Metal sulphates (radiopacity) (1-17%)
Additives, pigments, trace metals (1-4%)

Question 6

what the different types of cones?

Answer 6

Standardised cones (International Organization of Standardization)

Accessory cones used in conjunction with spreaders

Greater taper cones (ProTaper GP point)