Exam 1- Biomaterials Flashcards
sealants, flouride, chlorohexidine
preventative dent materials
replace, repair, or rebuild
restorative materials-direct (in mouth) and indirect (out of)
Auxillary materials
used to form, do not become a part of device (i.e. gypsum and dental wax)
composite material
mix of 2 of the 3 (metal, ceramic, or polymer)
example of composites
glass/resin/silica
mouth is usually ___ temp
warmer than RT
Class I device
low risk; good manufacturing
Class II
meet performance standards; most
Class III
requires data to support; for newer materials
Sets standards and regulations for america
ADA-1859
set the international standard
ISO
electrical insulators
covalent bonds-electrons don’t move
Metallic Bonds
Sharing of e- between two solids; electrons are free thus they are electrical and thermal conductors
Interatomic Primary Bonds
Metals are able to deform due to rearrangement of electric forces whereas ionic solids would have repulsive forces that cause cracks to form
Amorphous
irregular arrangement of atoms with no long range order upon solidification (glass and many polymers)
Crystal
A regular arrangement of atoms that exhibit long range order upon solidification (most metals and some ceramics)
Atomic Crystal Structure
Depends on length of axis connecting adjacent atoms and angles between them
most dental materials are
cubic
number of ways lattice exist
14
adhesion
force of attraction between molecules on two different
cohesion
force of attraction within a material
undercuts
mechanical bonding
Phosporic acid
leaves rough surface for bonding
wetting
degree an adherent will spread on a surface-measured by contra angle
Smaller angle
greater wetting
theta equal to 180
no wetting
ideal adhesive
low surface tension and adheres with high energy
High energy
balls up
low energy
spreads flat
long range order
crystak
number of crystal structures
7
no long range order
amorphous
