Fundamentals of Dental Materials Flashcards
A narrow space around 3/4 of each rod giving enamel a keyhole shape. It makes the boundary between rod and interrod enamel.
Rod sheath
Structural component of the hydroxyapatite-embedded collagen matrix
Intertubular dentin
Composes the bulk of dentin
Intertubular dentin
limited to the lining of the tubular walls and densely packed with apatite crystals
Peritubular dentin
- What structure is in red?
- What strucutre is in blue?

- Red- Intertubular dentin
- Blue- Peritubular dentin
What is the strongest and simplest molecular bond?
Covalent bonds
What property of dental materials causes toxicity and sensitivity reactions that occur locally or systemically within associated tissues?
Biological
Why will a low surface energy liquid readily spread over a high surface energy substrate?
Surface energy
What is the measure of the affinity of a liquid for a solid as indicated by the spreading of a drop?
Wettability
What are the two surface properties of materials
- Surface energy
- Wettability
Adsorption
dissimilar substances in intimate contact with the surfaces of a solid (i.e. adherence)
Will high or low energy surfaces adsorb molecules more readily?
High…. on a mountain top
Absorption
The uptake of liquid by a bulk solid. The substance absorbed diffuses into the solid material.
What happens when there is an uptake of liquid by a bulk solid?
Absorption
What describes the action of dissimilar substances in intimate contact with surfaces of a solid?
Adsorption
Which biocompatibility test is performed by placing a material in a situation indentical to its inteded clinical use? (i.e. in animals or humans)
Usage tests
What happens when materials may not bond with sufficient strength to resist contraction on polymerization, wear, orthermal cycling?
Microleakage
Microleakages can lead to
Gaps between tooth and restoration which allows influx of materials that may irritate the pulp.
What pulpal reaction is caused by insufficiant bonding strength of materials which then influx to irritate the pulp?
Microleakage
What is the most important protection of the pulp?
Remaining Dentinal Thickness (RDT)
What is the minimum thickness of the RDT?
0.5mm