Quiz 1: Bonding to Dental Substrates Flashcards
Defined enamel bonding using MACRO and MICRO tags:
Where do they form?
With what kind of gel?
- Macro and micro tags formed on etching with phosphoric acid gel
What are the three steps/procedures in Dentin bonding?
- Etching
- Priming
- Bonding
( Remember: Dentin is almost 25% water making its surface strongly hydrophilic. The goal is to produce microtags for micro-mechanical retention
In etching:
- What two things does etch remove and from which layer?
- What two things does etch expose? ( One is a layer type and the other are certain tubules.. what are they).
- Removes the smear layer
- Removes HA from the outer dentin layer (about 5 µ)
- Exposes a collagen sponge layer
- Exposes the dentin tubules
In etching:
Why must care be taken after etching?
– Care must be taken after etching to prevent drying of the dentin surface to keep the collagen sponge layer from collapsing on itself
In priming:
Define the HYBRID LAYER formation:
– What is of importance of the hybrid layer?
- The process of impregnation of the etched dentin by the resin in the primer.
- Hybrid layer is critical to bonding and creates necessary microtags.
In priming on the dentin layer, the hybrid layer may vary in what?
– If this zone (dentin) is not fully impregnated with primer, What will happen?
- May vary in thickness
- - A space may create a mechanically weak zone.
What are the purpose of the solvents present in primers?
The primers have solvents to enhance wetting and carry the monomers into the tags
Why are several layers of primer may be needed?
May be needed to carry the monomers deep as the solvent evaporates.
What is hemin?
The primary chemical in primer
Where does the primer penetrate into?
Primer penetrates into open dentinal tubules (generally under cured and may be of little value to bonding as flexible tags)
What happens if etching is too deep?
May be difficult to fill the hybrid zone with primer.
Bifunctional monomer in primer links to what?
- Hydrophilic collagen
- - Hydrophobic resin
What is Self-Etch?
- How many steps?
- What two things are present in self-etch?
- Two-step system
- - Combined conditioner and primer
In bonding, most bonding is a result of what type of retention?
– Micro-mechanical retention
