Etching and Bonding

Question 1

What is the smear layer

Answer 1

A layer of organic debris that remains after prep pf dentine and normally contains bacteria
it interferes with adhesion and must be removed

Question 2

3 components of total etch

Answer 2

detine conditioner/etch
Primer
adhesive/bond

Question 3

What does the dentine conditioner do

Answer 3

it opens up the dentinal tubules by removing smear plugs
decalcifies the upper most layer of dentine

Question 4

What does the primer do?

Answer 4

It is a coupling aget
a biofunctional molecule
HEMA

Question 5

What does the adhesvie do

Answer 5

BIS GMA and HEMA
it also is light cued (camphorquinone)
it pentrates the primed dentine which has hydrophobic surface and forms micromechancal bond with tububles and exposed collagen and forms a hybrid layer

Question 6

What are the disadvantages of total etch

Answer 6

mositure denpendent (dry = dentine surface collapses, wet = primer dilute leading to reduced strength)
tech sens
over etching causes collapes of collagen fibres so resin can’t pentrate

Question 7

Advantages of self etch

Answer 7

no rinsing
no detine collapes
decrease in tech sens
reduced sesn due to no drying stage

Question 8

Disadvantages of self etch

Answer 8

greater variability between products in pH (lower intial pH may not etch enamel effiecntly)