Restorative Resins Essay Question And Answers

Restorative Resins Important Notes

1. Definition of composites

It is a compound composed of at least two different materials with properties that are superior or intermediate to those of an individual component.

2. Composition of composites

3. Classification Of Composites

• According to the particle size
  • Traditional composite – 8-12 pm
  • Small-sized composite – 1-5 pm
  • Microfilled composite – 0.4-0.9pm
  • Hybrid composite – 0.6-1 pm
• According to filler particles
  • Megafilled
  • Macrofilled
  • Midfilled a Minifilled
  • Microfilled e Nanofilled
• According to the polymerization method
  • Self-curing
  • Ultraviolet light curing
  • Visible light curing
  • Dual curing

4. Chemically Activated Composites

• Supplied in two pastes
• Base – contains initiator benzoyl peroxide
• Accelerator – contains tertiary amine as an activator
• Manipulated by mixing in proper proportions on a mixing pad with an agate spatula
• The cavity is slightly overfilled
• Shrinkage occurs towards the center of the material

5. Light-Activated Composites

• Contains single paste
• Initiator – Camphoroquinone
• Activator – ‘diethyl-amino-ethyl-methacrylate
• They are activated to the light of wavelength 400-500 nm
• Ultraviolet light is not indicated

Read And Learn More: Dental Materials Question and Answers

• Source of light – tungsten halogen bulb
• The tip should be kept as close as possible
• Cured in increments
• Exposure time – 40-60 sec
• Shrinkage occurs towards the light source.

Restorative Resins Long Essays

Question 1. Classify composite resin restorative materials. Describe its composition, properties, and uses of it.
Answer:

Composite Resin:

A solid formed from two or more distinct phases that have been combined to produce properties superior to or intermediate to those of the individual constituents is described as a dental composite

Composite Resin Classification:

• According to the particle size
  • Traditional composite- 8-12 μm
  • Small-sized composite-1-5 μm
  • Microfilled composite- 0.4-.0.9 μm
  • Hybrid composite- 0.6-1 μm
• According to Filler particles
  • Mega filled
  • Macrofilled
  • Midfilled
  • Minifilled
  • Microfilled
  • Nanofilled
• According to the polymerization method
  • Self-curing
  • Ultraviolet light curing
  • Visible light curing
  • Dual curing

Composite Resin Composition:

Composite Resin Properties:

Composite Resin Uses:

• Restoration of classes 1, 2, 3, 4, 5, 6
• Discolored tooth
• Midline Diastema Cases
• Veneers And Laminates
• Bonding Of Orthodontic appliances
• Restorations of non-carious lesions
• Core foundation
• As indirect restoration
• For periodontal splinting

Question 2. Discuss the advantages and disadvantages of light cure composite resins.
Answer:

Light Cure Composites:

• They are of two types
  • Visible light composite resin
  • UV light composite resin

Light Cure Composites Advantages:

• Easy manipulation
• No mixing required
• Infinite working time
• Short controlled setting time
• The amount of finish and polish required is much less
• Less waste of material

Light Cure Composites Advantages of Visible Light Over UV Light:

• Can be cured to a greater depth
• Elimination of health hazard
• No warm-up time required
• No decrease in the intensity of the light source
• To maintain adhesion to cavity walls in a deep cavity incremental technique can be used

Light Cure Composites Disadvantages:

Question 3. What are anterior restorative materials? Discuss in detail composite resins.
Answer:

Anterior Restorative Materials:

• Silicate cement
• Glass ionomer cement
• Acrylic resin
• Composite resin
• Porcelain
• Composites

Question 4. write details about the various components of composite resins. Add a note on the posterior composite.
Answer:

Posterior Composites

Posterior Composites Indications:

• Small, incipient lesion
• Possible to control moisture
• As core foundation
• Patient with low caries index

Posterior Composites Contraindications:

• Difficult to control moisture
• Extensive lesion
• High occlusal stresses
• Presence of parafunctional habits
• Patients with high caries index and poor oral hygiene

Posterior Composites Advantages:

• Esthetic
• Conservative
• Micromechanical bonding
• Economical compared to indirect restoration
• Absence of galvanism

Posterior Composites Disadvantages:

• Polymerization shrinkage
• Technique sensitive
• Time-consuming
• Expensive compared to amalgam

Posterior Composites Procedure:

• Tooth preparation
  • Use small round bur initially
  • Extend preparation using fissure bur
  • Maintain minimal depth
  • Faciolingual dimension 1/4th of the intercuspal distance
  • No need for retentive features
  • Converge occlusal walls
  • Round line angles
  • Bevelling of enamel margins
• Matrix placement
• Etching of the preparation with 37% phosphoric acid
• Application of primer and adhesive
• Pulp protection
• Use of calcium hydroxide as base
• GIC as liner
• Composite placement
• Done in increments with subsequent curing it
• Finishing and polishing

Restorative Resins Short Essays

Question 1. Hybrid Composites
Answer:

Hybrid Composites

• Hybrid composites are developed to have better surface smoothness and esthetic characteristics
• It contains two kinds of filler particles

Hybrid Composites Filler Type

• Heavy metal glasses
• Average particle size- 0.4-1 μm
• Colloidal silica
• Size- 0.04 μm

Hybrid composites Properties:

Question 2. Fillers and their role in composite resins
Answer:

Fillers and their role in composite resins

• Fillers are added to the resin matrix to improve its properties
• Composites are classified on the basis of the average size of major filler component

Composite Resins Functions:

• Increases hardness
• Increases strength
• Decreases wear
• Reduces polymerization shrinkage
• Reduces thermal expansion and contraction
• Increases viscosity
• Decreases water sorption, softening, staining
• Increases radiopacity
• Decreases curing shrinkage

Composite Resins Factors Affecting Filler Selection:

• Amount of Filler added
• Size of particle
• Shape of Filler
• Index of refraction
• Radiopacity
• Hardness

Composite Resins Types:

• Quartz Filler
• Glasses or ceramics containing heavy metals
• Boron silicates
• Lithium aluminum silicates
• Ytterbium trifluoride
• Colloidal silica

Question. 3. Classification and uses of composite resins
Answer:

Composite Resins Classification

• According To The Particle Size
  • Traditional composite- 8-12 μm
  • Small-sized composite-1-5 μm
  • Microfilled composite- 0.4-.0.9 μm
  • Hybrid composite- 0.6-1 μm
• According To Filler Particles
  • Mega filled
  • Macrofilled
  • Midfilled
  • Minifilled
  • Microfilled
  • Nanofilled
• According To The Polymerization Method
  • Self-curing Ultraviolet light curing
  • Visible light curing
  • Dual curing
• Composite Resins Use:

• Restoration of Class 1,2 3, 4, 5, 6
• Discolored tooth
• Midline diastema cases
• Veneers and laminates
• Bonding of orthodontic appliances
• Restoration of non-carious lesions
• Core foundation
• As indirect restoration
• For periodontal splinting

Question 4. Dual cured composites
Answer:

Dual cured composites

• Dual cure resins combine chemical curing and visible light curing components in the same resin
• So-called dual cure resins

Dual cured composites Composition:

• Supplied in two pastes system
• One contains benzoyl peroxide and the other contains an aromatic tertiary amine

Dual cured composites Action:

• When two pastes are mixed and then exposed to light, light curing is promoted by the amine or chloroquine combination
• Chemical curing occurs by amine/ benzoyl peroxide combination

Dual cured composites Advantages:

Can be used for cementing crowns or bulk restorations where there is limited light penetration

Dual cured composites Disadvantages:

• Air inhibition
• Porosity

Question 5. Microfilled composites
Answer:

Microfilled composites

Microfilled composites were developed to overcome the surface roughening and translucency of traditional Composites.

Microfilled composites Properties:

Microfilled Composites Clinical Considerations:

• Mechanical properties are inferior to another types of composite
• Esthetic is better than other composites
• Thus it is for anterior teeth in non-stress-bearing areas because decreased physical properties do not create a problem here
• In stress-bearing areas, they have a potential for fracture
• Sometimes chipping occurs at the margins

Question 6. Contents and their role in composite resins
Answer:

Contents and their role in composite resins

Question 7. Light cure composites.
Answer:

Light Cure Composites Are

• There are two types of light cure composites
• Visible light composite resin
• UV light composite resin

Light Cure Composites Advantages:

• Easy manipulation
• No mixing required
• Infinite working time
• Short controlled setting time
• The amount of finish and polish required is very less
• Less waste of material

Light Cure Composites Light Sources:

• Light emitting diodes
• Quartz tungsten halogen lamps
• Plasma arc curing lamps
• Argon laser lamps

Restorative Resins Short Question And Answers

Question 1. Composite resin
Answer:

Composite resin

A solid formed from two or more distinct phases that have been combined to produce properties superior to or intermediate to those of the individual constituents is described as a dental composite

Composite Resin Uses:

• Restoration of Class 1,2 3, 4, 5, 6
• Discolored tooth
• Midline diastema cases
• Veneers and laminates
• Bonding of orthodontic appliances
• Restoration of non-carious lesions
• Core foundation
• As indirect restoration
• For periodontal splinting

Question 2. Filler in composite resin
Answer:

Filler in composite resin

• Fillers are added to the resin matrix to improve its properties
• Composites are classified on the basis of the average size of major filler component

Filler In Composite Resin Functions:

• Increases hardness
• Increases strength
• Decreases wear
• Reduces polymerization shrinkage
• Reduces thermal expansion and contraction
• Increases viscosity
• Decreases water sorption, softening, staining
• Increases radiopacity
• Decreases curing shrinkage

Question 3. Visual light cure composite
Answer:

Visual light cure composite

Wavelength used- 460-470 nm

Visual light cure composite Mechanism:

• On activation, the photoinitiator combines with an amine accelerator
• Release of free radicals
• Polymerization

Visual light cure composite Photoinitiator Used

The photoinitiator used is camphor quinone

Visual light cure composite Advantages:

Improved color stability

Question 4. Photoinitiators
Answer:

Photoinitiators

• Camphoroquinone is a commonly used photoinitiators
• It absorbs blue light with a wavelength between 400-500 nm
• Exposure to light in the blue region produces an excited state of the photoinitiator
• It interacts with the amine to form free radicals that initiate addition polymerization
• Only small quantities of camphor quinone are required
• A number of amine initiators are suitable for interaction with camphor quinone such as dimethylamino-ethyl methacrylate

Question 5. Coupling agents in composite resins
Answer:

Coupling agents in composite resins

• The coupling agent bonds the filler particles to the resin matrix
• The most commonly used coupling agent is organosilanes
• In the presence of water, the methoxy group of it forms an ionic bond with the filler particle
• On the other end, the methacrylate group forms a covalent bond with resin when it is polymerized

Coupling Agents Functions:

• Transfers stress to filler particles
• Improves physical and mechanical properties
• Inhibits leaching by preventing water from penetrating along the filler resin interface

Question 6. Composition of composite resin
Answer:

Composition of composite resin

Question 7. Light-activated composites
Answer:

Light-activated composites

• There are two types of light-activated composites
• They are
• Visible light-activated composites
• UV light-activated composites

Light-Activated Composites Advantages:

• Easy manipulation
• No mixing required
• Infinite working time
• Short controlled setting time
• The amount of finish and polish required is very less
• Less waste of material

Light-Activated Composites Light Sources:

• Light emitting diodes
• Quartz tungsten halogen lamps
• Plasma arc curing lamps
• Argon laser lamps

Question 8. Microfilled vs conventional composite resins
Answer:

Microfilled vs conventional composite resins

Question 9. Bis-GMA
Answer:

Bis-GMA

• It was developed by RL Bowen in early 1960
• It is a high molecular weight monomer formed by a reaction between a molecule of ethylene glycol of bisphenol A and glycidyl methacrylate

Bis-GMA Functions:

• Reduces polymerization shrinkage
• Increasesstrengthandrigidity
• Increases viscosity

Bis-GMA Limitations:

• High viscosity
• Difficulty in synthesizing a pure composition
• Strong air inhibition to polymerization
• High water sorption because of diluents used
• Polymerization shrinkage
• It does not adhere to tooth structure