Dentine bonding

Question 1

why do we do wet bonding?

Answer 1

over-drying of etched dentine results in collapse of the collagen layer -> reduced bond strengths

Question 2

how does dentine caries affect bond strength

Answer 2

lower bond strength
dentine softer
hybrid layer thicker -> deeper acid penetration

Question 3

how does sclerotic dentine affect bond strength?

Answer 3

Reduced acid and resin penetration
Lower bond strength

Question 4

how does age of dentine affect bond strength?

Answer 4

bond strength similar throughout life
dentine thickness and hardenss increases with age
reduced tubule diameter, fluid and permeability

Question 5

how does toot depth affect bond strength?

Answer 5

lower bond strength deeper in dentine
Inner dentine wetter and less tubular

Question 6

how does the smear layer affect dentine bond strength?

Answer 6

Smear layer has low bond strength to dentine
The way dentine is cut can determine the thickness of the smear layer for example diamond burs give dense smear layers

Question 7

how does dentine permeability affect bond strength

Answer 7

Permeability increases with depth
Wetness reduces bond strength

Question 8

how does pulpal pressure affect bond strength?

Answer 8

Increased pulpal pressure decreases bond strength

Question 9

what affect does LA with adrenaline have on bond strength?

Answer 9

lower pulpal pressure -> better bond strength

Question 10

what affect does LA plain have on bond strength

Answer 10

increases pulpal pressure -> reduces bond strength

Question 11

how does treatment like desensitisers affect dentine bonding?

Answer 11

Oxalate salts occlude tubules -> reduces resin penetration and bond strengths