3/11: Types of Cement and Their Uses Flashcards
What are types of cements?
Zinc phosphate
Zinc oxide eugenol
Zinc polycarboxylate
Glass ionomer
Resin-modified glass ionomer
Provisional cements
Note that no cement will perform to it’s optimal level clinically without an ______________________ that includes good resistance and retention form
Adequate preparation
What are characteristics of cements?
Biocompatibility
Retention
Mechanical properties - withstand occlusal forces, high tensile strength
Marginal seal
Low film thickness
Ease of use
Radiopacity
Esthetics
What is the first cement appearing in dental literature?
Zinc phosphate
What cement is the standard which other cements are assessed?
“gold standard”
Zinc phosphate
What are advantages of zinc phosphate?
Thin film thickness and proven reliability
Low solubility which resists breakdown in the mouth
Low thermo-conductivity - provide less sensitivity to hot and cold
Long shelf life
What are disadvantages of zinc phosphate?
Initial low pH- can lead to pulpal irritation
No chemical adhesion/bond
No antibacterial properties
Poor esthetics (for all porcelain)
Long setting time: 2.5-8 minutes
Exothermic - chill glass slab when mixing, small amounts of powder added to liquid
What are two types of Zinc oxide eugenol (ZOE) cement?
Type I
Type II
How do the two types of ZOE differ?
In their properties and uses
Describe type I ZOE
Less strong and used for temporary restorations and for temporary cementation (temp-bond)
Describe type II ZOE
Reinforced and stronger
Last for 6-12months in the mouth
Used for a tooth that cannot ber estored immediately (IRM)
What cement is referred to as an intermediate restoratie?
Type II ZOE
What is the benefit of ZOE?
Neutral pH
Has a sedative or soothing effect on the dental pulp
!A protective or insulating base or liner is not required
When is ZOE not used?
Under composite or acrylic restorations because eugenol is incompatible with these materials and retards their setting process
What determined whether the powder is incorporated into the liquid in increments or all at once?
The type adn intended use
What is the mixing/setting time of ZOE?
Mixing: Usually 30-60 sec
Setting: 3-5 min
When and why was zinc polycarboxylate developed?
1968 - to circumvent pulpal problems associated with low pH
What was the first cementing system to obtain an adhesive agent that bonded to enamel and dentin?
zinc polycarboxylate