Liners and cements

Liners and bases are materials placed as thin coatings between the dentin and the restoration, that mainly act as a barrier against chemical irritation, to provide pulpal protection and resist the condensation force.

Liners protect the dentin from residual reactants diffusing out of the restoration or oral fluids that may penetrate the leaky tooth restoration interfaces.

Bases are materials used as barriers against chemical irritation, and resist the condensation force.

Types of cements and liners:

· Cavity Liners: Glass ionomer, Calcium hydroxide (Resin based cement)

· Cavity Sealers: Varnish, Adhesive sealers

· Bases: (conventional cement)

1) Zinc phosphate cement

2) Glass ionomer

3) Reinforced zinc oxide

4) Zinc poly-carboxylate cement

· Cavity Liners: (Resin based cement)

Resin cements are composite resin filling materials with higher mechanical properties and are insoluble in oral fluids. They need pulp protection, as they are irritating to the pulp.

Calcium hydroxide (CaOH) is a liner suspended in a solvent with a thickening agent. It has 2 components: a base and a catalyst.

· Cavity Sealers:

VARNISH: A varnish is a solution of one or more resins derived from synthetic resin and natural gums.

Bases: (conventional cement)

1) Zinc phosphate (ZOP) — (90%) magnesium oxide (10%).

2) Zinc oxide — In ZnOE cements are designed particularly for permanent cementation of inlays, crowns and bridges. ZOE products are available in paste-paste or powder-liquid varieties

3) Zinc polycarboxylate (ZPC) — This powder-liquid material bonds to the tooth due to the polyacrylic acid reacting with the calcium on the surface of the enamel and dentin, with the bond to enamel being greater than that to dentin.

Polycarboxylate cement is cohesive to metal but it is adhesive to the tooth. The wettability of the cement should be improved with the metal to achieve a metallic bond at the cement metal interface, failing which it can lead to a weak bond at the cement metal interface.

Based on their properties and uses, the dental cements are of 3 types:

Luting agents — Permanent and temporary cements

Restorative materials — Glass ionomers

Liners — Cavity preparation

Source: Google Images

This video demonstrates the procedure for doing corono-radicular restoration with resin composite core material.

Dentals Inc. has the best range of cements and liners.

Contact Dentals.ca for all your specific needs.

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