LIVE Aesthetic Zirconia: High Translucency

YTZP Zirconia Translucency Test Results

Comparison of 9 commercially available brands in USA

ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia

Objectives:

The purpose of this comparative test is to show the translucency level (total light transmittance: TLT) of 9 commercially available brands of zirconia discs that are most widely used in U.S.A. The level of translucency is one of the most important components in optical characteristics of crown and bridge restorative bio-material

 

Methods:

1. Sample Preparation

Total of 9 commercially branded zirconia discs were chosen for a test comparison of translucency levels.

Company

Brands

Enlargement

Factor

Shrinkage

Rates

Lot/Ref/

SN/Batch#

Manufacturer

Manufacturing

Method

1

Zirkon Zahn

Prettau

1.2508

20.05%

ZA9101B

Italy

Isosatically/Biaxial

2

Doceram

Nacera ZT

1.2489

19.93%

3090109

Germany

Isosatically/Biaxial

3

German

Conventional Substructure

1.2598

20.62%

I10332

Germany

Isosatically/Biaxial

4

Origin

Live Plus

1.2282

18.58%

NS0098-46

USA

HSD Method*

5

Glidewell

BruxZir

1.2239

18.29%

BZHT12ZI

USA

Colloidal

6

Sagemax

NexxZr

1.2406

19.39%

WTCLJ

USA

Isosatically/Biaxial

7

Crystal

Diamond

1.2406

19.39%

DTBEC

USA

Isosatically/Biaxial

8

3M

LAVA Plus

1.2383

19.24%

479361

3M

Isosatically/Biaxial

9

Talladium

Luminesse HT

1.2512

20.08%

2428

USA

Isosatically/Biaxial

2. Test Sample Size and CNC Milling

Multiple small disc samples were created as STL files using Solidworks (Dassault Systems SolidWorks Corporation, MA, USA) 3D design software. Then the samples were milled using each manufacturers enlargement factor so that the dimensions of each sample would measure 17.5 mm (diameter) X 1.00 mm (thickness) after final sintering and polishing (the samples were slightly thicker than 1.00 mm after milling to allow an exact thickness of 1.00 mm after polishing). An enlargement factor of 1.2500, for example, is equivalent to a shrinkage rate (1/1.2500=0.200) of 20%. This clarification is given since these concepts of enlargement factor and shrinkage rate are often used interchangeably by mistake in the dental industry.

 

The sample thickness of 1.00 mm was chosen, instead of 0.6mm or 0.5mm, since these zirconia materials being tested are primarily and preferably used for full contour crown and bridge applications of which the thickness of the body portion, mesial, ligual and distal area would be normally 1-2 mm in thickness. Test samples of 0.5 - 0.6 mm thick that are found in publications of other manufacturers would be more appropriate for the application of crown and bridge substructures (copings or frameworks).

ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia

3. Polishing & Sintering

After precision CNC milling, both sides of each of the samples were mirror polished using 3M Imperial Wetordry 401 Q (2500A grit) and then surface cleansed with Isopropanol alcohol ((CH3)2CHOH). Each surface was polished to an extent to clearly reflect the light to minimize surface deflection of the light source in the spectrophotometer.

 

Each different brand of zirconia was sintered according to each manufacturer's recommendation as appears in their Instructions For Use manual or published website information. The sintering schedule for each material type is below. To ensure accuracy and consistency in temperature of the sintering chamber, Process Temperature Control Rings (PTCR from Ferro, Netherlands) were used each time multiple samples were sintered. After going through this sintering process, the samples are understood to be fully sintered and no post HIP processing was done.

 

Sintering Schedule of Test Samples (Manufacturer’s recommendation)

Brands

Doceram Nacera ZT

Zirkon Zahn

Crystal Diamond

SageMax NexxZr T

Talladium

Pentron Zirlux FC

3M Lava Plus

BruxZir

Origin Live Plus

C°/min

 

 

 

 

 

10

 

 

 

Temp 1

 

 

 

 

 

600

 

 

 

C°/min

8

8

3

3

10

2 - 5

10

10

25

Ramp up time

 

 

 

 

 

 

150 min

150 min

60 min

Temp 2

1600

1600

1500

1510 - 1530

1500

1500

1450

1530

1530

Dwell Time

2:00

2:00

1

2

1:00

2:00

2:00

2:00

1:00

Cooling (°C/min)

-8

-8

Natural

-7

Natural

Natural

Natural

Natural

Natural

ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia

4. Measuring the Translucency

One method of measuring translucency is by determining total transmission, including scattering, using a spectrophotometer with an integrating sphere as shown below. Translucency of a material can be expressed as a transmission coefficient or total (direct and diffused) light transmittance(%) as the relative amount of light passing through the unit thickness of the material. Total light transmittance was measured by a double beam-system spectrophotometer (LAMBDA 35, UV/Vis Spectrophotometer manufactured by Perkin Elmer, USA) based on “Standard test method for transmittance and color by spectrophotometer using hemispherical geometry” of ASTM E1348-11 and “Materials and articles in contact with foodstuffs – Test methods for translucency of ceramic articles” of Dansk Standard/EN 1184.

 

All the samples were cleaned with isopropyl alcohol before light transmittance measurement. Light emitted from a light source (deuterium lamp and halogen lamp) was passed through a sample and scattered, and the light transmission amount was measured using an integrating sphere.

 

5. Equipment Used

Perkin Elmer LAMBDA 35 UV/VIS Spectrophotometer, USA

ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia

6. Measure of Total Light Transmittance (TLT)

Visible light which had passed through the sample was collected with an integrating sphere to determine the intensity of the visible light (I) as it passed through the sample. On the other hand, the intensity of visible light (I.sub.0) was measured without placing the sample. The total light transmittance was calculated in terms of the proportion of the former to the latter intensity (=I/I.sub.0). A transmission spectrum and digital data record were obtained for each measurement with the light beam entering the samples.

ORIGIN LIVE Plus Dental Zirconia
ORIGIN LIVE Plus Dental Zirconia

YTZP Zirconia Translucency Test Results

Comparison of Commercially Available High Translucent Zirconia Brands in USA