D2 Biomaterials Lecture 11: Endodontic Materials

In what way is the root canal prepared in endodontic treatment?

Mechanically

What two conditions are prevented by temporary restorations?

1. Coronal leakage

2. Salivary contamination

What is done to help flush out debris and microorganisms in the root canal?

Irrigation

What is the primary antimicrobial irrigant?

Sodium hypochlorite

What is the irrigant used to remove the smear layer?

EDTA

What is the most widely used intracanal medicament?

Calcium hydroxide

Which component of sodium hypochlorite is the more potent antimicrobial species?

HOCl

What is the concentration rage for sodium hypochlorite irrigation?

0.5 - 6%

What is the major advantage of sodium hypochlorite irrigation?

Dissolves organic tissue

What is the concentration of EDTA irrigation?

17%

What is the other irrigation that can remove the smear layer?

Citric acid

What does the removal of the smear layer open?

Dentinal tubules

What is the broad-spectrum antimicrobial agent that does not dissolve organic tissue?

CHX

What does CHX provide for the tooth?

Substantivity

Why should CHX not be mixed with sodium hypochlorite?

Precipitate

What is released by calcium hydroxide for antimicrobial activity?

Hydroxyl ions

What type of environment is produced by calcium hydroxide?

Highly alkaline (pH = 12.5)

What is the most widely used core material for obturation?

Gutta-percha

What is prevented by gutta-percha and sealent?

Microbial leakage

What is the major inorganic filler of gutta-percha?

Zinc oxide

What gives gutta-percha thermoplastic properties?

Waxes/Resins

What gives gutta-percha radiopacity?

Metal sulfates

Why is sealer needed with gutta-percha?

Does not chemically bind to dentin

What is the synthetic polymer-based alternative to gutta-percha?

Resilon

What is the sealer system used with Resilon?

Epiphany/RealSeal

What is formed when Resilon is used with sealers?

Monoblock

What are the three main components of MTA?

1. Calcium

2. Silicon

3. Aluminum

What is formed by mixing tricalcium aluminate with water?

Ettringite

When is MTA used as a root-end filling material?

Apical surgery

What must be formed by sealers?

Hermetic seal

What should the radiographic appearance of sealers be?

Radiopaque

Should the setting time for sealers be fast or slow?

Slow

What reaction does Zinc Oxide-Eugenol-Based Sealers use to set?

Acid-Base reaction

What is provided by eugenol before setting?

Antimicrobial activity

What might be interfered with eugenol?

Polymerization of resin-based restoration

Which resin-based sealer has good dimensional stability and flow?

Epoxy

Which resin-based sealer promotes adhesion to root dentin?

Methacrylate

What is the main concern with methacrylate resin-based sealers?

Polymerization shrinkage

What is the methacrylate resin-based sealer made for Resilon?

Epiphany

What reaction with Calcium Silicate-Based sealers allow the release of ions that make an alkaline environment?

Hydration

What are the three main advantages of Calcium Silicate-Based sealers?

1. Hydrophilic

2. High pH

3. Good flow

What are the two main disadvantages of Calcium Silicate-Based sealers?

1. Solubility

2. Retreatment difficulty