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Classification of Materials, Medinna Rasha - 2506557816 - Coggle Diagram
Classification of Materials
Metals
Composition
Pure metals (one type of atom)
Example: Gold, Titanium
Alloys (≥2 elements, at least one metal)
Metal–metal (Au–Ag)
Metal–non-metal (Steel = Fe + C)
Structure
Crystalline lattice
Closely packed atoms in layers
Layers can slide → malleability & ductility
Crystal types:
FCC → ductile (gold)
BCC → strong, less ductile (iron)
HCP → strong, less ductile (titanium)
Bonding
Metallic bonding
Positive metal ions + delocalised “sea of electrons”
Non-directional bonding
Properties
Good strength
Malleable & ductile
Good thermal & electrical conductivity
Clinical Relevance
Amalgam restorations
Orthodontic wires
Titanium implants
Ceramics
Composition
Metal + oxygen
Examples: SiO₂, Al₂O₃, ZrO₂
Structure
Ionic bonds in 3D lattice
Crystalline + amorphous phases
Crystal–glass ratio affects strength & translucency
Bonding
Ionic bonding
Strong, directional bonds
Properties
Hard
Brittle
High melting point
Chemically resistant
Clinical Relevance
Crowns
Veneers
Inlays
Fixed partial dentures
Polymers
Composition
Long-chain macromolecules
Elements: C, H, O, N
Made from monomers
Structure
Linear
Branched
Cross-linked (most dental polymers)
Amorphous or partially crystalline
Bonding
Primary: Covalent bonds (within chains)
Secondary: Hydrogen bonds, Van der Waals forces
Additives
Initiators
Accelerators
Plasticizers
Fillers
Pigments & stabilizers
Coupling agents
Properties
Lightweight
Flexible
Easy to manipulate
Gradual softening (no sharp melting point)
Clinical Relevance
Denture bases
Impression materials
Resin restorations
Composites
Definition
Combination of ≥2 materials with superior properties
Components
Matrix
Resin (Bis-GMA, UDMA)
Binds components
Reinforcement
Fillers (particles, fibers)
Increases strength & wear resistance
Coupling Agent
Silane
Bonds matrix to filler
Structure
Matrix (continuous phase)
Reinforcement (dispersed phase)
Interface / interphase
Fiber orientation:
Unidirectional
Bidirectional
Multidirectional
Bonding
Covalent bonds (resin matrix)
Silane coupling bonds
Secondary interactions
Clinical Relevance
Composite restorations
Esthetic fillings
Medinna Rasha - 2506557816