What is a good way to prevent contamination of saliva or oils?
rubber dam
What do you have to do if contamination at any step of the bonding process occurs?
re-etch
What term is used to describe the process of attaching restorative materials by adhesion?
bonding
What is the first step in the bonding process?
preparation of the surface of the tooth including removing plaque and debris
How do you remove plaque and debris from the tooth surface in preparation for bonding?
etching or conditioning enamel or dentin with acid
What is the most commonly used acid in etching? And what does it do?
phosphoric acid
removes tooth mineral to create porosity
What happens when a resin bonding agent or primer is flowed over the etched surface?
it penetrates into the microscopic pores
What happens when the resin bonding agent hardens?
creates a mechanical bond called 'resin tags' that lock into the tooth (mechanical bond)
What type of bond is a resin to resin or composite to resin?
chemical bond or primary bond
What type of bond is a true adhesion between atoms or molecules of the composite resin and the bonding resin?
chemical bond
true or false. the chemical bond is stronger than the weak physical bond
true
acid etching increases the ability of liquids to wet the surface of the tooth by creating a _________
high surface energy
good __________ increases the intimate contact of the bonding resin with the etched tooth structure, improving the penetration of resin to form tags and thereby improving the bond
wetting
What helps to attract the resin to the etched surface?
high surface energy
surfaces that are poorly wet will cause what?
beading of the liquid
Etching of enamel removes a small portion of the __________, reduces the ends of the _________ __________, and opens _________ between adjacent rods
surface
enamel rods
porosities
What is the optimal time for etching?
20-30 seconds
What type of teeth may require up to 60 seconds of etching?
highly mineralized teeth such as fluorosis
How long should you etch primary teeth?
60 seconds
Why do primary teeth have to be etched for longer amounts of time?
because the surface of the enamel has a prism pattern that is not as well structured, it is aprismatic
What is the recommended rinsing time for acid etch gels?
10 seconds or longer
true or false. rinsing time for liquid etch can be shorter, like 5-10 seconds
true
Does dentin or enamel have a higher water and organic content?
dentin
What are 3 components of dentin?
collagen matrix
mineral (hydroxy appetite)
dentinal tubules
layer formed when a cavity preparation is cut with rotary or hand instruments, a layer of cutting debris forms on the surface of the cut dentin and enamel
smear layer
why does dentin need to be etched for a shorter amount of time than enamel?
because enamel is more highly mineralized
How long should dentin be etched?
10 seconds
What happens if you etch dentin for too long?
opens dentinal tubules too wide and removes hydroxyapatite mineral to too great a depth
It decreases bond strength and increases hypersensitivity
What happens if the dentin is dried too much during the dentin acid process?
collagen fibrils collapse and form a dense surface that occludes the tubules and blocks adequate penetration by the dentin bonding resins
___________ are low-viscosity resins that flow well into the microscopic porosities and irregularities of the etched surfaces
bonding agents
agents bonding to what material alone requires only a low-viscosity liquied resin monomer that will penetrate into the spaces on and between __________ _________ created by acid etching
enamel
enamel rods
What allows resins to penetrate water on the dentin and in the dentinal tubules and to penetrate around collagen fibrils and into porosities in the tooth surfaces created by etching?
solvents
aceton, ethanol, or a combination of ethanol and water are what?
solvents
What are the 2 components of dentin bonding agents?
resin primer
resin adhesive
Which resin penetrates etched dentin and enamel and is a mechanical bond?
