Dental Cements Ch14 (W11) Flashcards
What is a thin layer of resinous material placed on the floor and walls of prep to seal tubules and minimize micro-leakage
Cavity varnish
What is the purpose of a liner
Thin layer of material placed to protect the pulp
What is a thick layer of cement used to protect the pulp from chemical and thermal irritation
Base
What does luting refer to
Cementing two components togetehr
In dentistry when the cement is set how does it appear
Hard and brittle
Type I cements are
Luting agents
What would you use a type I cement for? (Luting agent)
Glue crowns, bridges, onlays& inlays
Cement or bond ortho band/bracket
*can be perm or provisional
Type II cements are used for
Provisional/intermediate restorations or long term
Type II cements may include
Glass ionomer cements
Dental sealants
Type III cements are
Bases or liners for cavity preps
Strength of a cement is controlled by amount of
Powder incorporated
The strongest dental cements are
Resin cements
The weakest dental cement is
Zinc oxide eugenol
Cements are ____ materials with good ____ strengths
Brittle; compressive
Resin containing cements are
Insoluble cements
Retention is accomplished by
Adhesion
What are two types of adhesion
Mechanical
Chemical
Interlocking of one material with another is what kind of adhesion
Mechanical
At molecular level- ionic bonding or covalent bonding describes what kind of adhesion
Chemical
In many dental applications, chemical and mechanical adhesion occurs
Together
Adhesive agent will decrease? It aids in ?
Decrease microleakage
Aids in retention
What are factors that may weaken the strength of adhesion between two materials
Coefficient of thermal expansion
Dimensional changes
Contamination
Material with low viscosity =
Luting agent
Luring cements help prevent microleakage by sealing the interface between the
Tooth and the restoration
Luring cements are classified according to their composition; what are the 3
Water based
Resin based
Oil based
Water based: zinc phosphate disadvantages
Pulp irritation
Weaker than other cements
Highly soluble (will wear away/wash away in time)
Water based: zinc carboxylate advantages
Adheres to tooth structures
Non irritating to pulp
Inexpensive
Disadvantages of zinc carboxylate
Higher solubility
Short working time
Lower strength
Water based: glass ionomer cement advantages
Chemical adhesion to tooth and metal
FLUORIDE RELEASE
Easy to mix
Moderate strength
Water based: glass ionomer cement disadvantages
Postoperative sensitivity
Does not bond to glazed porcelain
Marginal solubility
Resin based luting cements help increase retention of crowns or teeth with less than ideal preps. What are the 4 groups? (Insoluble)
Esthetic resin cements
Adhesive resin cements
Self adhesive resin cements
Provisional resin cements
Oil based luting cements: ZOE. What is it used for
Provisional cementation
Provisional and intermediate restos
Low strength bases
Root canal sealers
Perio dressing
ZOE should NOT be used when because it may inhibit the set of the resin
Under composite restos or as provisional cement before final cementation with resin modified glass ionomer or resin cements.
What causes pulpal irritation
Bacteria effect of caries
Biologic response to chemicals in dental materials
Cutting off tooth structure
What can be used to act as protective layers between the dentin and the restorative material
Cavity varnishes
Liners
Bases
Cavity varnish is applied in 2 or 3 thin layers where in the prep?
Floor and walls
Cavity varnishes are used under what restos? What are they not used under?
Used under amalgam restos
NOT used under composite resins
What does a protective base do
Protects the pulp before the resto is placed
What does an insulating base do
Protects the tooth from thermal shock
What does a sedative base do
Soothes the pulp that has been damaged by decay or irritated by mechanical means
Low strength base is aka
A liner
Examples of low strength base (aka liner)
Calcium hydroxide (dycal)
Class ionomer
Zinc oxide eugenol (has sedative effect)
What does a low strength base aka liner do?
-Provides minimal strength to support forces of condensation
-stimulates growth of secondary dentin
-provides a barrier btwn pulp & resto
-used as a direct pulp capping agent
High strength base is aka
Base
What does a high strength base aka base do
-Provides thermal insulation & support for resto
A base is placed in areas where there is less than
2mm of remaining dentin over the pulp
What thickness is a base placed in
0.5mm or greater
Examples of bases
Reinforced ZOE
Zinc phosphate
Zinc polycarboxylate
Glass ionomer
What is the purpose of surgical dressings
Provide protection and support for the surgical site
Patient comfort
Helps control bleeding
What consistency are provisional and intermediate restorations mixed to
Secondary consistency
ZOE should not be used as a base or provisional cement if
Composite resin or resin bonding agents are used
Glass ionomer cements release what? Therefore what effect do they have
Release fluoride
Have anti cariogenic effect
Do Products that do not release fluoride, only contain fluoride have antiocariogenic effects?
No
