CHAPTER 44: DENTAL LINERS, BASES & BONDING SYSTEMS Flashcards
What is a cavity liner
- placed in the deepest area of excavation of cavity preparation
-protects the pulpal tissue from irritation
calcium hydroxide properties
-protects the pulp from irritation caused by physical, mechanical and biologic elements
-stimulation of secondary dentin
- It is compatible with all types of restorative materials.
Types of cavity liners
calcium hydroxide
glass ionomer
which liner is compatible with all restorative materials?
calcium hydroxide
forms strong bond to dentin and reduces microleakage
glass ionomer
What is a cavity sealer?
provides a protective layer within the PREPARED cavity.
types of a cavity sealer
Varnish
Flouride varnish
Desensitizer
has a higher fluoride concentration than any other fluoride marketed, being 5% or 22,600 ppm fluoride
fouride varnish
a type of sealer that consists of one or more natural resins dissolved in an organic solvent
varnish
application of varnish does what?
seals dentinal tubules
reduces microleakage around a restoration
protects the tooth from a highly acidic base (ie. zinc phosphate)
the use of fluoride varnish are as follows:
• Professional fluoride application
•hypersensitivity
• Orthodontic patients
• Cavity varnish
• Dentin sealant
when should varnish be applied?
after the liner is applied
What does dental varnish interfere with ?
composite resin
glass ionomer restorations
what is a desensitizer?
a type of sealer used to protect the tooth from hypersensitivity
what is the difference between a varnish and a desensitizer?
The chemical makeup of the product.
desensitizer is made out hydroxyethyl methacrylate (HEMA) and glutaraldehyde
in what areas of the tooth should a desensitizer NOT come in contact with ?
soft tissue
What is a dental base?
placed before the permanent restorative material when a tooth preparation becomes moderately deep to deep.
placed when it is necessary to protect the pulp before the restoration is placed. Without this protection, postoperative sensitivity and damage to the pulp may occur.
protective base
placed in a deep cavity preparation to protect the tooth from thermal shock. (Thermal shock occurs when sudden temperature changes occur within the tooth.)
insulating bases
base that help soothe a pulp that has been damaged by decay or has been irritated during the process of removing the decay.
sedative bases
types of dental bases (cement bases):
Zinc oxide–eugenol (ZOE)
Zinc phosphate cement
Polycarboxylate cements
Glass ionomer cement
cannot be used under composite resins, glass ionomers, or other resin restorations. The eugenol in the liquid will affect the setting process of the resin materials.
zinc oxide eugenol
this liquid has a soothing effect on a painful, irritated pulp.
eugenol
properties of zinc phosphate
-pros: thermal insulation qualities
-cons: acidic, irritating to the pulp
can be selected for use as an
insulating base and as a
sedative base
Zinc oxide–eugenol
which bases are nonirritating to the pulp and can be placed under all types of direct and indirect restorations.
Polycarboxylate
where is the base applied during restoration
between the pulp and the restoration
The entire pulpal floor is covered with a base to a thickness of 1 to 2 mm
what is a dental etchant?
prepares enamel for the attachment of a bonded restoration
what is the tooth surface etched with
acidic tooth conditioner
The preparation of a tooth surface is critical for both ____and _____ surfaces of a cavity preparation to form a better chemical bond between the tooth and the permanent restorative material.
enamel
dentin
what is removed when etchant is applied to a tooth
smear layer
how many seconds should an etchant be applied
15-20 seconds
the process of attaining a solid and/or liquid contact of one material with another at a single margin
dental bonding
types of dental bonding
enamel bonding
dentin bonding
examples of enamel bonding
placement of sealants, braces, and use of resin bonded bridges.
what does enamel bonding do
bonds dental materials to the enamel by hardening them into place
A major factor in the success of bonding a material to dentin is the removal of what ?
smear layer
thin layer (5–10 microns) of debris composed of fluids and tooth components that remain on the dentin after cavity preparation has been completed
smear layer
why is the smear layer removed before dentin bonding?
allows the dentin tubules to become opened for the bonding material to flow into.
process of removing smear layer
application of an etchant
If dentin is completely dried, the tooth structure could be harmed. TRUE OR FALSE
TRUE
The following general description outlines what occurs in the bonding system:
tooth receives etchant which removes smear layer
hardens and acts as a hybrid layer
or
remain in a liquid state while restoration is being placed.
one of the most frequently selected types of cavity liner
calcium hydroxide
