Aesthetic Resin Restorations

Question 1

What are the 3 types of aesthetic resin restorations

Answer 1

Composite resin
Poly-acid modified Resins ( Compomers )
Resin Modified Glass Ionomers

Question 2

Requirements for ideal composite resin?

Answer 2

Biologically acceptable
Dimensional stability
Acceptable mechanical properties
Acceptable physical Properties
Adhesion to tooth structure using a enamel-dentine bonding system
Insoluble in Saliva
The material must imitate normal tooth structure
Radiopaque

Question 3

How can polymerization shrinkage be reduced?

Answer 3

Incremental packing,keeping the C-Factor in mind, correct application of the bonding system and the use of highly filled composite resins.

The more organic fillers ,the less organic resin monomer matric —> the less polymerization shrinkage and stress.

Question 4

How does water absorption affect dimensional stability?

Answer 4

Water absorption results in expansion — which is also referred to as hydroscopic expansion.

This results in the weakening of the bond between the filler particles and resin within the composite

Question 5

What are some mechanical properties?

Answer 5

Compressive Strength, Tensile strengh, Surface hardness, acceptable physical properties

Question 6

What are some good aesthetic properties of resin materials

Answer 6

Opaque
Acceptable refraction index
Resistance to discoloration due to food ,smoke
Colour stability
Variation in color for good aesthetics

Question 7

What are the 4 major components in dental composites resins

Answer 7

An Organic monomer matrix - Di-methacrylate resin monomers

Inorganic dispersed fillers - Glass, quartz, silica

A coupling agent - Saline which adheres the monomer matrix to the filler particles

A polymerization initiator - Camphorquinone to get the process of polymerization started

Question 8

What are a few organic resin monomers

Answer 8

Bis-GMA resin
UDMA
TMA
4-META
TEGDMA

Question 9

What are inorganic fillers?

Answer 9

They are either large particles of quartz or small particles of silica or a combination of both

Question 10

Advantages of filler particles

Answer 10

Fracture resistance increases, the more filler in the composite the more viscous it becomes.

Question 11

Functions of fillers

Answer 11

Improves mechanical properties
Reduces polymerization shrinkage
Reduces the COTE
Reduce amount of water absorption
Reduces the exothermic reaction
Improves aesthetics
Adds radio-opaque

Question 12

What is a Coupling agent

Answer 12

It helps to produce a bond between the inorganic fillers and organic monorms matrix.

Silane is a bi-functional molecule as it is capable of reacting with the inorganic fillers, as well as with the organic resin monomer matrix.

Question 13

What is the critical role of the coupling agent?

Answer 13

Preventing crack propagation

Question 14

An example of a polymerization initator?

Answer 14

Camphorquinone

Question 15

An example of a polymerization inhibitor

Answer 15

Butylhydroxytoluene

Question 16

What does a polymerization inhibitor due?

Answer 16

It prevents premature or spontaneous polymerization of the resin monomers

Question 17

What are nano-filled/ nano-hybrid composites?

Answer 17

They are extremely small particles, due to their size higher filler levels can be achieved in the restorative materials which results in

improves aesthetics and excellent physical properties

Question 18

Examples of Nano-filled/nano-hybrid composites

Answer 18

Filtek Supreme ETE, Filtek Z350, Filtek Supreme Ultra universal

Question 19

What are composites with spherical filler particles

Answer 19

Granulated spherical fillers are used in combination with an optimised resin matrix system

Example - Ceram.X

Question 20

What is a composite core?

Answer 20

The primary purpose of a core build-up material is to replace missing tooth structure and to permit creation of ideal retention form and resistance form for crown and bridge preparations

Question 21

Example of composite core

Answer 21

Filtek one bulk fill restorative (3M)

Question 22

What is condensable composite?

Answer 22

These materials have a very high filler content therefore high viscosity.

only used in posterior teeth

Due to high viscosity there is a potential lack of adaptability.

Question 23

Flowable composites

Answer 23

These materials contain less filler particles and are therefore not as strong as the universal composite
- they undergoe high polymerization shrinkage due to low filler content
-
Example - filtek z350 xte flowable

Question 24

Flowable are most often used as?

Answer 24

Preventative resin restorations and restoration of attrition facets

Question 25

What are bulk fill composites

Answer 25

They are compositesdveloped to save time and incremental packing uptil 4mm is possible

Question 26

Characteristics of Bulk fill composites

Answer 26

Low poly shrinkage and shrinkage stress to decrease micro leakage
Improved depth of cure atleast 4mm
More Flowable to all better cavity adaptation
very good compressive strength

Question 27

Indications for bulk fill Composites

Answer 27

• Liner/base for class 1 and class 2 direct restorations
• Pit and fissure sealant
• Conservative Class 1 restoration with low occlusal forces
• Core build up
• Restoration of primary molars

Question 28

Advantages of hybrid /nano-filled composites?

Answer 28

Are radioopaque
Good finishing and polishing can be achieved
Durable and able to withstand occlusal forces
More favourable co-efficent of thermal expansion

Question 29

Why do we bevel cavity preps for composite restorations?

Answer 29

It increases the surface available for bonding and results in a better aesthetic result

Question 30

How does micro-leakage occur?

Answer 30

Incorrect placement techniques ( poor adaptation and marginal leakage )

Polymerization shrinkage also causes micro-leakage

Inadequate light curing will cause micro-leakage