Modulus of Rupture and Hardness of Opaque Dental

8/10/2019 Modulus of Rupture and Hardness of Opaque Dental

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Modulus of Rupture and

Hardness of Opaqueental Porcelain

Fathie Kundie

Universiti Kebangsaan Malaysia

International Conference of Engineering & Built Environment (ICEBE) 2013, Puri Pujangga, UKM Bangi, Selangor, Malaysia.

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Introduction

Porcelain plays a vital role in restorative dentistry.

It has many uses, such as crowns, veneers, artificial

teeth inla s and onla s brid es and castable

ceramics.

A desirable feature of ceramics is that theirappearance can be customized to simulate the

colour, translucency and fluorescence of natural

teeth.International Conference of Engineering & Built Environment (ICEBE) 2013, Puri Pujangga, UKM Bangi, Selangor, Malaysia.

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Introduction

Malaysia has to import the dental porcelain,

this led to an increase of it price and therefore

to increase the treatment costs.

porcelain at the School of Materials

Engineering - Universiti Sains Malaysia.

The purpose of this study was to evaluate

modulus of rupture and hardness of locally

produced opaque dental porcelain.International Conference of Engineering & Built Environment (ICEBE) 2013, Puri Pujangga, UKM Bangi, Selangor, Malaysia.

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Materials and Methods

Combination of 13 different raw materials was

used to produce opaque dental porcelain.

Preparation of the opaque dental porcelain

powder begins with characterization of the raw

materials.

Three different additives i.e. zirconium, cerium

and vanadium oxides are selected for this task.International Conference of Engineering & Built Environment (ICEBE) 2013, Puri Pujangga, UKM Bangi, Selangor, Malaysia.

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Each pellet was sintered using dental furnace

for three minutes.

The soaking time at the maximum temperature

980C is 1 minute.


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Materials and Methods The locally prepared Opaque Dental Porcelain

was compared with the Commercially Available

Opaque Dental Porcelain.

Both powders were prepared as a pellet and

sintered at the same temperature.

Both pellets were subjected to the same testing

procedures.


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Hardness test was carried out using Vickers

Hardness Tester (FUTUER-TECH, Model FV-7).

Modulus of Rupture (MOR) test was applied by

Instron 3366.


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Results

Hardness test

The specimens of opaque dental porcelain have

higher values of hardness compared to the

commercially available opaque dental porcelain

as shown in Figure 1.


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Results/Hardness

357.72

496.42

400

500

600

700

essH

V

0

100

200

300

Commercial opaque dental porcelain Opaque dental porcelain

Hard

FIGURE 1: Vickers hardness for commercial and opaque

dental porcelains.International Conference of Engineering & Built Environment (ICEBE) 2013, Puri Pujangga, UKM Bangi, Selangor, Malaysia.

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Results Modulus of Rupture (MOR) Test

It was found that the MOR for commercial opaque dental

porcelain is higher than the opaque dental porcelain due

to differences in the microstructure.

Furthermore, there are differences in the composition

and sintering temperature for both porcelains which

affects the microstructure consequently affects the

strength.

Figure 2 shows the Youngs modulus for two groups of

opaque dental porcelain.International Conference of Engineering & Built Environment (ICEBE) 2013, Puri Pujangga, UKM Bangi, Selangor, Malaysia.

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Results/ MOR

40.2481

25

30

35

40

45

50

atYield

17.9752

0

5

10

15

20

Commercial opaque dental porcelain Opaque dental porcelain

Stres

FIGURE 2: Youngs modulus for commercial and opaque

dental porcelains.International Conference of Engineering & Built Environment (ICEBE) 2013, Puri Pujangga, UKM Bangi, Selangor, Malaysia.

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Conclusion

The experiments to produce opaque dental

porcelain show that opaque dental porcelain can

be obtained and its hardness was higher than

the commercial one.

The comparison between both opaque dental

porcelains showed that more systematic studies

are needed to obtain good properties of opaquedental porcelain.


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THANK YOU


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Modulus of Rupture and Hardness of Opaque Dental