L116: Fundamentals of Dental Materials Science Flashcards
What are the main things to consider when choosing a dental material?
- What is available for the treatment?;
- Is it fluoride releasing?;
- Composition;
- Characteristics;
- Working and setting time.
What is amalgam creep?
The movement (change of shape and protrusion) of amalgam over time.
What kind of forces can cause amalgam to fracture over time?
Continuous low level forces
What component of composite filling determines its viscosity?
Glass filler particles
What is the purpose of etching teeth prior to the application of composite?
To create a rough surface on the tooth, leading to better adhesion to the tooth material and surrounding enamel
What is the purpose of fluoride releasing restorative materials?
To increase the enamel’s resistance to development of caries
Does amalgam or composite resist compressive strength/ fracturing best?
Amalgam
What is thermal expansion and why must restorative material expand/contract?
Expansion and contraction with the tooth material to prevent microleakage and further caries
Low viscosity impression materials…
are most accurate for recording tooth surface detail.
High viscosity impression materials…
are most dimensionally stable after setting and removing.
Which type of impression material is used in impression trays?
High viscosity
Which type of impression material is used around individual teeth?
Low viscosity
Give an example of a negative replica:
Impression
Give an example of a positive replica:
Dental cast
Young’s modulus =
Elasticity
Viscosity is:
The ability to flow
Elasticity is:
The ability to return to to its original shape upon the removal of an applied force
Rigidity is:
A measure of how much force is needed to cause a temporary change in the shape of material
Compressive strength is:
The ability to withstand applied compressive forces without fracturing
Hardness is:
The ability of a surface to withstand indentation and resist abrasion (i.e. removal of a surface layer)
Creep is:
Change in shape due to repetitive application of small forces
