Which base is contraindicated under composite resins?

# Which of the following is contraindicated beneath composite resins as liner/ base? The correct answer is B. Zinc oxide -eugenol. The advantages of ZOE cement are that it gives excellent seal, has a sedative effect on prepared sensitive teeth, cost-effectiveness, and ease of removal of cemented temporary restorations.

Why is it not used under a composite resin?

However it is not compatible with resin composite materials because it blocks adhesion and has a detrimental effect on the bonding properties.

Can you use Dycal under composite?

Further studies are necessary to suggest that Dycal can be used without any inhibitions under composite resin restorations, may be in vivo studies with long-term follow-up of the outcome are required.

What base materials can be used with composite restorations?

A suitable base material for composite resin restorations: zinc oxide eugenol.

Is zinc oxide eugenol compatible with composite?

Zinc oxide–eugenol cements should be used with caution under resin-based composite restorations because the eugenol can inhibit the polymerization of the resin. A glass ionomer cement base may be placed over zinc oxide–eugenol before the placement of resin-based composite in order to avoid polymerization.

TheraCal LC as a liner in a Class II resin based composite restoration

Why is zinc oxide-eugenol contraindicated under composite?

... Traditional base materials, such as zinc oxide-eugenol cements, have been contraindicated for composite restorations due to inhibition of resin polymerization by the phenolic hydrogen of eugenol.

Can calcium hydroxide be used under composite?

Studies have shown that calcium hydroxide “softens” under amalgam and resin-based composite restorations. The results are attributed to hydrolysis of the calcium hydroxide by fluid contamination from dentinal tubules and microleakage.

Why Zoe is not used as a base under composite?

One of the most accepted and indisputable statements in restorative dentistry is that cavity bases containing Zinc-Oxide-Eugenol (ZOE) have a negative effect on polymerization of conventional composites, yielding weaker restorations.

What lining can be used under a composite filling?

In our practice, we have traditionally used resin modified glass ionomer (RMGI) liner/bases for deep cavities and composite procedures. By their nature, RMGI liners are typically fluid materials that can adapt more readily to the internal aspects of a cavity preparation.

What base is used under amalgam?

Zinc oxide eugenol (ZOE) is the traditional base for amalgam restorations.

Can we use Dycal under GIC?

CaOH under GIC is redundant and counterproductive. One is placing a hard compressive strength materiral (GIC) on a softer one (Dycal). The rate of reparative dentin is constant and is not determined by the use of Dycal.

Can you use Dycal and Vitrebond together?

Both studies demonstrated that the pulp–dentin complex response to Vitrebond and Dycal indicated acceptable biocompatibility of these materials and there are no statistically significant difference between calcium hydroxide and Resin-Modified Glass Ionomer.

Is Dycal a liner or base?

Dycal® Calcium Hydroxide Liner is a two-component, rigid-setting, self-curing material designed for use in direct and indirect pulp capping and as a protective liner under dental adhesives, varnishes, filling materials, cements, and other base materials.

What is a disadvantage of calcium hydroxide as a lining material?

Calcium hydroxide has significant drawbacks; the low elastic modulus and low compressive strength of calcium hydroxide cavity liners restricts their usage to thin layers in specific areas, which is not critical to the support of restorations.

What is a base for a filling?

Common bases under dental fillings are glass ionomer cement and zinc phosphate cement. The purpose of the base is to insulate the tooth and protect it from temperature changes in the mouth. Both the dentist and patient can choose various materials to be used as the tooth filling.

Is calcium hydroxide a base or liner?

Calcium hydroxide is a low strength base that can be used as a liner, intermediary base or pulp-capping agent.

Why is a lining used under a filling?

Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure.

Can you use ZOE with composite?

According to many investigations, a resin-based composite material should not be used over ZOE because it increases microleakage and produces poor bond strength to dentin because eugenol suppresses the polymerization of composite resin [11,12].

What is zinc oxide eugenol used for?

Zinc oxide/eugenol cements are mixtures of zinc oxide (powder) and eugenol (liquid). They are mainly used as a lining or base under amalgam restorations and as temporary luting cements or filling materials.

Can IRM be used as a base?

IRM may also be used as a base under cements and restorative materials that do not contain resin components, such as amalgams, and inlays and onlays. Its strength properties approach those of zinc phosphate cement. IRM has excellent abrasion resistance, good sealing properties and low solubility.

What is Dycal composition?

Dycal® is a paste-paste calcium hydroxide dental cement uses as pulp capping and liner in dentistry. First paste (base paste) contains titanium dioxide and barium sulphate in glycol disalicylate and second paste (catalyst paste) contains calcium hydroxide, zinc oxide and zinc stearate in ethyl toluene sulphonamide.

Is calcium hydroxide base?

Calcium hydroxide, also known as slaked lime (with the chemical formula Ca(OH)2) is a source of hydroxide ions when dissolved in aqueous solutions. Therefore, this compound is a base.

Do you etch before Dycal?

10 The loss of material from Dycal as a result of acid contact is generally regarded as disadvantageous. Therefore, etching procedure should be done before Dycal application.