Sales Training 2014 - Dentistry

Ch_14_DM.indd 237 5/13/2013 12:35:47 PM

Table 14.2 Summary of materials used as liners, bases, and sub-bases. Material Used Commercial Names Composition

Type of Reaction

Clinical Situation

Advantages

Disadvantages

• Can be coated on internal surfaces close to the cavosurface margin • Seals margins of freshly inserted amalgam restorations • Capable of inducing secondary dentin formation • Forms a stable, adherent layer • Command set with light, so ample working time • Available in single tube, no mixing required

• Cannot be used under GIC or composite resins • Provides only initial thermal and electrical insulation under metallic restorations • Very short working time • High solubility • Placement is difficult; tends to stick to the instrument • It does not provide thermal and electrical insulation

Solution liner

Varnish

Copal varnish

Natural copal/nitrated cellulose resin, acetone/ alcohol May contain eugenol, thymol, or fluorides Calcium hydroxide and organic solvent (methyl ethyl ketone/ethyl alcohol or aqueous solution of methyl cellulose) UDMA resin, Ca(OH) 2 , barium sulfate, HEMA, photoinitiator

No reaction Evaporation of solvent leaves a thin film

RDT ≥ 2 mm Used under amalgam restorations

Suspension liner/low strength bases

Calcium

Dycal, Calcimol, Pre-line

RDT < 1 mm Used under GIC and composite resin restorations

hydroxide

Calcimol LC, Septocal LC

Photo- polymerization

RDT < 1 mm Used under GIC and composite resin restorations RDT = 1–2 mm Used under interim restorations RDT = 1–2 mm Used under composite restorations

Light-cured Ca(OH) 2

Powder: Zinc oxide, rosin, zinc acetate, zinc stearate Liquid: Eugenol

• Adequate working time

• Difficult to maintain consistency after mix

Zinc oxide eugenol (type IV)

Kalzinol

Chelation reaction

• Highly biocompatible • Chemical adhesion • Anticariogenic • Good sealing due to CTE close to that of tooth • Obtundent effect on the pulp

• Technique and moisture sensitive • Increased solubility • Removal of excess is difficult

High

GIC

Fuji Lining LC, Vitrebond, Ketac-Bond

Acid–base reaction

strength bases

Powder: Zinc oxide, hydrogenated rosin, zinc acetate, zinc stearate Liquid: Eugenol, polystyrene/ methylmethacrylate Powder: Zinc oxide, magnesium oxide, other oxides Liquid: Orthophosphoric acid Powder: Zinc oxide, magnesium oxide, and other oxides Liquid: Polyacrylic acid, copolymers of other acids

Reinforced ZOE IRM

Chelation and polymerization reaction

RDT = 1–2 mm Under amalgam restorations

Chapter 14 * Dental Cements 237

• High compressive

• Pulpal irritant due to low initial pH • Mechanical retention only

Reinforced ZOE Zinc phosphate

Harvard Cement, Hy-Bond

Acid–base reaction

RDT = 1–2 mm Under amalgam restorations and inlays/onlays

strength to withstand forces of condensation

• Good thermal and electrical insulator • Chemical adhesion • Biocompatible • Anticariogenic

• Short working time • Difficult manipulation

Zinc polycarboxylate

Hy-Bond Polycarboxylate Durelon, Poly F

Acid–base reaction

RDT = 1–2 mm Used under composite and amalgam restorations

CTE, coefficient of thermal expansion; GIC, glass ionomer cement; HEMA, hydroxyethyl methacrylate; IRM, intermediate restorative material; RDT, remaining dentin thickness; UDMA, urethane dimethacrylate; ZOE, zinc oxide eugenol.