Dental cements

Question 1

process of attaching one structure to another w/ use of intermediate agents like cement
-prosthesis are attached to teeth

Answer 1

luting

Question 2

• to protect pulp

- therapeutic like stimulation of secondary dentin formation

Answer 2

liner

Question 3

• thicker/stronger than liner
• thermal insulation
• condensation forces

Answer 3

base

Question 4

a very thin layer applied on wall of cavity including margins

• prevents chemical irritants from entering pulp
• prevent initial microleakage

Answer 4

varnish

Question 5

Classification

Answer 5

• based on application:
  
  • temporary cementation-zinc oxide eugenol
  • permanent
• based on composition

Question 6

cements for pupal protection

Answer 6

• calcium hydroxide

- ZOE cement

Question 7

Types of cement

Answer 7

• Silicate
• Zinc silicophosphate
• zinc phosphate (zinc cement)

Question 8

zinc phosphate cement
commercial names: de Trey, Harvard cement

-classification

Answer 8

• powder:yellowish/cream color
• liquid: clear
• Type 1: luting cement film thickness 25um<
• typeII: all other use 40 um

Question 9

Zinc phosphate cement

powder compostion

Answer 9

• zinc oxide
• magnesium oxide (to reduce temp of calcination process)
• silicone dioxide aids in calcination
• bismuth trioxide-imparts smoothness
• stannous fluoride

Question 10

zinc phosphate

liquid

Answer 10

• phosphoric acid
• aluminum, zinc, their compounds: help in partial neutralization of the acid to reduce the reactivity. est smooth, nongranular, workable cement mass during mixing

Question 11

zinc phosphate

chemistry of setting

Answer 11

• zinc oxide + phosphoric acid -> zince phosphate

- zinc phosphate + aluminum (in liquid)-> zincealuminophosphate gel

Question 12

zinc phosphate

consistency of mix

Answer 12

• luting consistency: fluid, glossy, stringed up
• base/filling: appears dull, thick, formed into rope
• mixing time: 60-90sec
• setting: 5-9min

Question 13

zinc phosphate

mechanical properties

Answer 13

• compressive strength
• tensile strength
• Influenced by:
• initial powder and liquid comp/ratio
• method of mixing
• handling of cement during placemnet

Question 14

copper cements

Answer 14

• similar to zinc phosphate, contain zinc oxide and phosphoric acid
• antibac effects
• black’s copper cement containing cupric oxide
• used in temporary restorations in pedodontic patients
• irritant to pulp

Question 15

zinc silico phosphate

-fluorothin, kryptex

Answer 15

• powder: pigmented opalescent powder
  
  • silicate glass in high zinc oxide powder
• liquid: clear, 50% phosphoric acid
• water
• aluminum/mercuric chloride

Question 16

zinc silicophosphate

properties

Answer 16

• doesn’t bond to tooth structure
• sim to zinc phosphate
• solubility to water high
• contains fluoride for release
• translucent
• manipulation:
  
  • powder incorporated in in 2-3 increments, mixing time <1min
• use: porcelain jacket crown
• filling deciduous teeth
• die material
• ortho brackets

Question 17

zinc silicophosphate
advantage
disadvantage

Answer 17

• high strength, anticariogenic, translucent

- high initial pH

Question 18

silicate cement
biotrey, silcap
Powder

Answer 18

• silica and alumina
• fluorides
• calcium phosphate

Question 19

silicate cement

liquid

Answer 19

• phosphoric acid
• aluminum silicate
• zinc phosphate
• water

Question 20

silicate cement

• advantage
• disadvantage

Answer 20

• high compressive strength
• anticariogenic property:fluoride is released to prevent caries in adj toothstructure
• esthetics
• high pH, injurious to pulp
• tends to stain
• high solubility