Exam 2: Surfaces and Interfaces

Question 1

adhesion concern in operative dentistry

Answer 1

dentin bonding in direct restorations/fillings

Question 2

adhesion concern in fixed prosthodontics

Answer 2

ceramic/metallic restorations and prostheses

Question 3

adhesion concern in pedodontics

Answer 3

sealants for prevention of decay

Question 4

adhesion concern in orthodontics

Answer 4

direct cementation of bracket and bands

Question 5

adhesion concern in endodontics

Answer 5

sealers to fill canal space

Question 6

when two unlike substances join together on being brought into contact because of forces of attraction b/t them

Answer 6

adhesion

Question 7

attraction between like molecules

Answer 7

cohesion

Question 8

a material used to produce adhesion

Answer 8

adhesive

Question 9

the substance to which an adhesive is applied

Answer 9

adherend

Question 10

example for adhesion: enamel/dentin and metal core of PFM are _____; dental cement is ______

Answer 10

adherends, adhesive

Question 11

overall, _____ adhere _____

Answer 11

adhesives, adherents

Question 12

adhesion ___ relates to properties of surface (____ ones of bulk of the materials)

Answer 12

directly, unlike

Question 13

adhesion requires…(4)

Answer 13

• fluid adhesive
• reactive adherend/solid surface
• interaction b/t adhesive and adherend
• creation of a stable interface

Question 14

surface tension relates to what substance?

Answer 14

liquids

Question 15

surface free energy relates to what substance?

Answer 15

solids

Question 16

the atoms in the surface interact _______ between them than the ones in the ____

Answer 16

more strongly, bulk

Question 17

the atoms in the surface are _____ than the ones in the bulk

Answer 17

more reactive

Question 18

force of attraction exerted on surface molecules of a liquid by the molecules beneath the surface

Answer 18

surface tension

Question 19

adhesion of atoms/ions/biomolecules or molecules of gas/liquid/dissolved solids to a surface

Answer 19

adsorption

Question 20

the incorporation of the molecules into the bulk of a material

Answer 20

absorption

Question 21

absorption: absorbed incorporated into _____

Answer 21

bulk of material

Question 22

adsorption: adhesion of substance to _____

Answer 22

surface

Question 23

when the adsorption involves a chemical reaction/strong bonding b/t adsorbed substance and surface

Answer 23

chemisorption

Question 24

when the adsorption involves establishment of weak/secondary/van der Waals bonds b/t adsorbed substance and surface

Answer 24

physiosorption

Question 25

if a surface is poorly wetted by water, it is _____ and has a ___ reactivity with water

Answer 25

hydrophobic, low

Question 26

if a surface is very much wetted by water, it is ____ and has a ___ reactivity with water

Answer 26

hydrophilic, high

Question 27

three mechanisms for adhesion

Answer 27

1. chemical bonding 2. micromechanical adhesion 3. hybridization bonding

Question 28

where a liquid flows into irregularities/pores/crevices in the adherend surface

Answer 28

micromechanical adhesion

Question 29

where one phase penetrates by diffusion into the surface of a 2nd phase, forming a hybrid layer

Answer 29

hybridization bonding

Question 30

chemical adhesions in dentistry

Answer 30

- glass-ionomer cements to tooth substance - adhesive resins to alloys - silane agents to ceramics - PFM (metal-ceramic interaction)

Question 31

micromechanical adhesion in dentistry

Answer 31

- adhesion to etched enamel - contributes to dentin bonding - abraded alloy surfaces - etched ceramics (HF)

Question 32

hybridization bonding in dentistry

Answer 32

-bonding to dentin