2/1: Intro to Biomaterials-Amalgam & Class I and Class V Restoration Flashcards
What are the 4 major classes of dental materials?
- Metals and alloys
- Porcelains and ceramics
- Polymers
- Composites
What are the two different types of polymers?
Elastomer (impression materials)
Plastics (denture base, sealants)
What are composites?
Polymers with fillers
How many specifications for dental materials, instruments, and equipment?
More than 10
What are restorative material specifications: related to material properties that should reflect clinical function?
In vitro (in glass)- tested in lab
In vivo (in the living beaing)
*Exploration of in vitro data to in vivo conditions should be done with caution
What two things does the food and drug administration focus on?
Safety, efficacy
What is the FDA’s goal?
Protect the public from hazardous or ineffective medical materials and devices
What class has the lowest risk?
Class I
What class has the highest risk?
Class III
Performance of all dental materials depends on ________
Atomic structure
What does atomic structure determine?
Mechanical and physical properties of materials
What are the two types of interatomic bonds?
Primary and secondary
What are primary interatomic bonds?
Ionic, covalent, metallic
What are secondary bonds?
Hydrogen bonds, Van der Waals forces
What are ionic bonds?
Electrostatic attraction of positive and negative charges
What do ionic bonds involve?
Electron transfer between ions (one becomes positive, one becomes negative ex: NaF)
What are properties of ionic bonds?
Non-directional, strong bonds
100-200kcal/mole
No free electrons, good thermal and electrical insulators
what are examples of ionic bonds?
Ceramics, gypsum
What are covalent bonds?
2 atoms share an electron
What are properties of covalent bonds?
Directional bonds
50-100kcal/mole
Low electrical and thermal conductivity
Water insoluble
What are examples of covalent bonds?
Water, glass, polymers, composite
What are metallic bonds?
Cluster of positive metal ions surrounded by a gas of electrons
What are properties of metallic bonds?
- non directional bonds (100 kcal/mole)
- high electrical and thermal conductivity
What are examples of metallic bonds?
Amalgam and gold alloys
What are biological classifications of material properties?
The biological response to a material when in contact with the human body
What is an example of a biological material?
Gingivitis from plaque
What is the surface classification of material properties?
The unique properties of a material associated with its surface
What is an example of a surface material?
Denture retention, adhesive bonding
What is the physical classification of material properties?
Depend on the type of atoms and the bonding present in material
What has NO EFFECT on physical classification of material properties?
Size or shape