Dental Composite Resin Notes

Composite Resins

Resins Composition: Resin matrix/binder, ground quartz, colloidal silica glasses/ceramics containing heavy metals, filler, coupling agents, and organosilanes.

BIS GMA (Bisphenol – a – Glycidyl methacrylate).

Classification of Composite Resins

Based on the mean particle size of the major filler

Read And Learn More: Basic Dental Materials Notes

Properties of Composite Restorative Material

Other Important

Acid etch technique- The most effective way of improving the bond and marginal seal between the resin and enamel.

The most commonly used- is 37% phosphoric acid.

Dental Amalgam Composition

Mechanism of action – Creates micro porosities, increases surface area, and increases the surface energy of enamel.

Bonding Agents Enamel bonding agent – BISGMA / TEGDMA

Dentin bonding agents – 3 generations

• 1st Generation – Glycero- Phosphoric acid methacrylate
• 2nd Generation – Chloro substituted phosphate esters of various monomers –
• 3rd Generation – A primer is applied followed by the application of polymerizable monomers
• 4th Generation
  • Prisma – NPG GMA and BPDM
  • Resin adhesive (40% BIS GMA, 30 % VDMA, 30% – HEMA)
  • HEMA – Hydroxy Ethyl Methacrylate
  • EDTA- Ethylene Di Amine Tetra Acetic acid
  • META – Methoxy Ethyl Trimellitic Acid

Bond Strength of Dentin Bonding Agent

Pit and Fissure Sealants

The most commonly and successfully used one is BIS – GMA resin

Dental Amalgam Composition

Resin Teeth Composition:

• Polymethyl methacrylate copolymerized with a cross-linking agent.
• High fractures toughness.
• Crazing if not cross-linked
• Dimensional change with water sorption

Porcelain teeth:

• Made with high fusing porcelains.
• Excellent biocompatibility
• The most suitable tooth-colored restorative material used to make denture teeth.
• Brittle, may chip
• Dimensionally stable
• Susceptible to crazing by thermal shock.

Dental Amalgam

Dental Amalgam Definition:

An amalgam is an alloy that contains mercury as one of its constituents.

Dental Amalgam Composition:

Phases of amalgam

Unique Properties of Amalgam

• Microleakage
• Dimensional change
• Effect of moisture contamination
• Strength
• Creep

Dental Amalgam Composition

Dental Amalgam Manipulation

• Selection of material – Alloy, mercury
• Mercury: alloy ratio (Proportioning) -Eames technique – Hg: Alloy = 1:1
• Trituration

Dental Amalgam Purpose: To wet all the surfaces of alloy particles with mercury.

Under triturated mix- Rough grainy, compressive, and tensile strength decreases, Normal-Shining surface with smooth and soft consistency, greatest compressive and tensile strength and resistance to tarnishing and resistance.

Over triturated- Mix is soupy, working time decreases, and higher contraction of amalgam.

• Mulling
• Condensation
  • Hand
  • Mechanical
• Trimming and carving
• Burnishing
• Polishing

Advantages and disadvantages of dental amalgam

Dental Amalgam (ADA-1)[Spotter]

Dental Amalgam Composition Example:

• Ag, Sn, Cu
• Recommended by GV Black
• ADA Requires That Amalgam alloys be predominantly Ag and Sn

Uses: Permanent filing material in classes 1,2 and 2 5, where esthetics is not a prime consideration in taking dies in retrograde root canal filling restoration of the crown.

Dental Amalgam Composition

Dental casting alloys

 

Dental casting alloys

Cobalt chromium alloy (ADA 14) [Spotter]

• High strength excellent corrosion resistance
• Bright lustrous hard strong and non tarnishing qualities

Dental casting alloys Applications:

• Denture base
• Surgical Implants

Dental casting alloys Composition:

 

Gold Alloys

Classification and composition of gold Alloys 

Direct filling gold

Gold Foil [Spotter] Applications:

• Pits and small class I restorations
• For repair of casting margins
• For class II & class V restorations

Dental Amalgam Composition

Gold Foil [Spotter]  Thickness:

• No 4 – weight 4 gms, 0.51 um thick
• No 3 – weight 3 gms, 0.38 um thick
• Used in the manufacture of electrolytic and powder products.

 

Abrasive And Polishing Agents

Typical Dentifrice Components 

Pumice: [Spotter]

It is a highly siliceous material of volcanic origin and is suited for use either as an abrasive or polishing agent depending and particle size.

Pumice Uses:

• Smoothing dentures.
• Polishing teeth in the mouth