From Production Skills to Scientific Knowledge,
and Onward to Fusion with Medical Science

Dental Adhesive

Safety Evaluation Report
Physical Properties and Safety of the Dental Adhesive,
Multi Primer
Vol.11
Vol.11 inin aa Series
Series on
on Safety
Safety Reports
Reports

YAMAKIN CO., LTD.

Head Office: 3-7 Sanadayama-cho Tennoji-ku Osaka 543-0015, Japan
Biological Science Safety Laboratory:
Laboratory in the Department of Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University
Kohasu, Oko-cho, Nankoku-shi, Kochi 783-8505, JAPANBranch Office: Tokyo, Osaka, Sendai, Nagoya, Fukuoka, JAPAN
P: +81-887-55-0281 F: +81-887-55-0053
E: contact@yamakin-gold.co.jp
INTERNATIONAL20190208

Organic Material Development Section
Biological Science and Safety LaboratoryIndex
1. Introduction ・・・・・・・・・・・・・・・・・・・・・・・・・ 2
2. Material Composition ・・・・・・・・・・・・・・・・・・・・ 4
3. Adhesion ・・・・・・・・・・・・・・・・・・・・・・・・・・・ 4
4. Durability ・・・・・・・・・・・・・・・・・・・・・・・・・・ 7
5. Biocompatibility ・・・・・・・・・・・・・・・・・・・・・・・ 9
6. Conclusion ・・・・・・・・・・・・・・・・・・・・・・・・・・ 12

Physical Properties and Safety of the Dental Adhesive,“Multi Primer”

metal alloy, and zirconia; their durability and biocompatibility were also evaluated.
We then compiled the results in "Safety Test Report Vol. 11, Physical Properties and Safety of the Dental
Adhesive ‘Multi Primer.’”
We hope that this test report will be of help as technical information for dental practitioners,
technicians, and patients.

1. Introduction
Teruo Anraku, Ph. D. in Engineering, Corporate Advisor of YAMAKIN CO., LTD.

Ritaro Matsuura, Ph. D. in Agriculture, Senior Chief Researcher, Biological Science and Safety Laboratory

Kato, T., Ph. D. in Engineering, Executive Officer, Head Researcher, Development Department

The resin material used for repairing a dental crown is built up on a frame and it can reproduce natural
teeth easily with excellent operability; as a result, hard resin is widely used. Also, for the implantsuperstructure, hybrid hard resin— which has the convenience of hard resin, and strength and aesthetics
superior to hard resin—is often used. On the other hand, cast precious metal alloy is generally used for asa material in the frame for repairing a dental crown. However, with the advance of digitization, it is now
possible to process dental materials with CAD/CAM, and zirconia, which suitable for cutting work, is
now widely used. It is expected that in the future there will be an increase in the number of cases using
non-precious metal alloys such as titanium or cobalt chromium alloy, which are difficult to process.
In frames produced by casting, a strong bond between the resin and frame is mechanically maintained byapplying retention beads. On the other hand, in the cutting process, unlike in the casting process,retention beads cannot be used. Therefore, a strong bond between resin and cutting frame cannot be
obtained; the chemical adhesion effect of the primer is therefore important. However, the chemicaladhesion of the adherend has a different optimum compound depending on the material of the adherend;
as a result, it is necessary to use primers appropriately for each frame material, resulting in complicatedtechnical operations.
Given the problem above, we have investigated a new primer with the development concepts of: (1) highadhesion strength; (2) long-term durability; and (3) excellent versatility (i.e., that it can be used forvarious materials in a more simpler manner). We then succeeded in developing the "Multi Primer" series.
The "Multi Primer" series is made up of three products. All of them can be used for building up our"Luna wing" and "TWiNY" hybrid resin for crowns.
The liquid-type primer "Multi Primer LIQUID" can also be applied to frames made of precious metalalloys, non-precious metal alloys or zirconia. The paste-type primer "Multi Primer PASTE" is a primer
for metals (precious metal alloys and non-precious metal alloys) and also achieves the opaquer functionof Invisible Opaque of "Luna-Wing" and "TWiNY." The liquid-type primer "Multi Primer REPAIR
LIQUID ONE" is a pretreatment liquid for additional layering by hard resin, when shape modification iscarried out. Each product has achieved greatly improved versatility by expanding and developing thefunctions of primers and the additional layering solutions adopted for "Luna Wing" and "TWiNY."

Dental materials are medical devices used in the oral cavity. Therefore, excellent biocompatibility isrequired for dental materials. However, the oral cavity, in which dental materials are used for long
periods of time, features harsh environmental conditions such as temperature swings, fluctuations in pH,
and chewing force. Thus, there is concern about adverse effect of poor-quality dental materials on thehuman body, since intraoral abrasion and dissolution of such products could cause human tissue to be
exposed to the components.
In order to resolve such concerns, our Biological Science and Safety Laboratory has established acollaborative research program with the Department of Oral and Maxillofacial Surgery, Kochi Medical
School, Kochi University to provide evidence about the biocompatibility of dental materials. For example,
we have conducted evaluations according to ISO 10993 "Biological evaluation of medical devices" 1) alongwith original in-house experiments and evaluations using cells, tissues and genetic engineering. We havesubsequently published the findings of our investigation as Safety Test Reports. Our Safety Test Reports(Vol. 4, “Biological Evaluation of Luna-Wing” and Vol. 8, “Biological Evaluation of Hybrid Resin,
TWiNY”), academic conference presentations 2), and academic papers 3) have shown excellent
biocompatibility of dental resin materials.
Resin material for dental crown restoration is built up on a frame, and reproduces natural teeth. Dental
primers are used to adhere the resin material to the frame tightly. Direct contact between dental primer
and human tissue in the oral cavity is unlikely but not impossible. Therefore, the biocompatibility ofdental primers should be evaluated.
In order to evaluate the biocompatibility of dental primers, we prepared clinical-mimetic test specimens
in which TWiNY was additionally built up on TWiNY using the newly developed "Multi Primer REPAIR
LIQUID ONE." We then conducted two cytotoxicity tests (Trypan blue-exclusion test and WST-8
cytotoxicity test) to investigate the effect of test specimens on the human monocytic leukemia cell line
THP.1.
Our series of Safety Test Reports has been issued in line with our mission to provide Safety andSoundness. We hope that this test report will deepen your interest in the biocompatibility of dental
materials, and resolve any concerns you may have about them.

In these tests, we examined adhesion between "Multi Primer" and precious metal alloy, non-precious

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· Multi Primer LIQUID
The main component of “Multi Primer LIQUID” is a volatile solvent (ethanol); small amounts of thiol
compound and silane coupling agent are included as priming components. The thiol compound is for
precious metals, and the silane coupling agent is effective for pretreatment of adhesion to non-precious
metals and ceramics.
· Multi Primer PASTE“Multi Primer PASTE” is mainly composed of monomers (urethane dimethacrylate and triethylene
glycol dimethacrylate) and silica fillers. It also contains small amounts of polymerization initiator,
polymerization co-initiator, pigments and priming components. The thiol compound and silane coupling
agent are employed for priming; a the thiol compound is for precious metals, and the silane coupling
agent is effective for adhesion to non-precious metals and ceramics. It also functions as an opaquer
corresponding to Invisible Opaque for “Luna-Wing” and “TWiNY.”· Multi Primer REPAIR LIQUID ONE“Multi Primer REPAIR LIQUID ONE” is mainly composed of monomers (urethane dimethacrylate andtriethylene glycol dimethacrylate). It also contains small amounts of polymerization initiator,
polymerization co-initiator, and a silane coupling agent as a priming component. Since hard resin ismainly composed of inorganic fillers and monomers, ceramics derived from the fillers is abundantly
exposed on the surface. We have designed the “Multi Primer” series so that a molecule of silane coupling
agent attaches effectively to a reaction site on the surface of the ceramics.
Table 1 Application of Primers
Application

Product

Conventional
Product

New Product

Luna-WingTWiNYMulti Primer

Name
PrimerState
LiquidNon-precious metal

Precious metal

Ceramics

Ti andTi Alloy

Ni-Cr Alloy

Co-Cr Alloy

Au Alloy

Au-Ag-Pd
Alloy

Zirconia
ZrO2

−

−

−

✓

✓

−

PrimerLiquid

−

−

−

✓

✓

−

Multi Primer LIQUID

Liquid

✓

✓

✓

✓

✓

✓

Multi Primer PASTE

Paste

✓

✓

✓

✓

✓

−

3. Adhesion

In the case "Multi Primer LIQUID", test specimens were prepared by the following steps. After applicationof Multi Primer LIQUID on the adherends, opaque resin was applied on the masked surface, the surface
was irradiated by light to polymerize it, and a stainless steel forming rod for tension was fixed on the cured
surface with resin cement.
In the case of "Multi Primer PASTE", test specimens were prepared by the following steps. Multi Primer
PASTE was applied on the surface of the masked adherends, the surface of the adherend was irradiated bylight to polymerize it, and a stainless steel forming rod for tension was fixed on the cured surface with resin
cement (Figure 1). The test specimens were kept in water at 37 °C for 1 day and then subjected to a test to
pull the stainless steel molded rods vertically to the adhesion surface at a speed of 0.5 mm/min, and thestress at fracture was taken as the tensile bond strength.
∙ In the case of Multi Primer REPAIR LIQUID ONE

Applying

Masking―4―

Applying Opaque(IVO)
and light curing

Fixing a stainlesssteel forming rod

Applying
and light curing

Fixing a stainlesssteel forming rod

Figure 1 Preparing test specimens for tensile bond strength test
As shown in Figure 2, it can be confirmed that the adhesive strength of the resin improves for each metal byuse of "Multi Primer LIQUID" and "Multi Primer PASTE". We also confirmed that "Multi Primer LIQUID"
is effective for zirconia.
60

Ti Alloy
Ni-Cr Alloy50

Co-Cr Alloy
Au Alloy40

Au-Ag-Pd Alloy
ZrO2

30
20
10
0

In the field of dentistry, it has been known that thiols are suitable for precious metals, phosphates for
non-precious metals 4) and silane coupling agents for resin materials 5) for priming. Recently, we have foundthat not only phosphate compounds but also silane coupling agents have an effect of improving resin
adhesion to non-precious metals 6). As a results, we have established that both thiol and silane coupling
agent can be applied in the priming of various materials 7).

Masking∙ In the case of Multi Primer PASTE

Tensile Bond Strength (MPa)

2. Material Composition

Without Primer

Multi Primer LIQUID

Multi Primer PASTE

Figure 2 Tensile bond strength between resin and each adherend

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25

Tensile Bond Strength (MPa)

Table 2 shows the compositions of metals (alloys) as adherend for the test.
Table 2 Compositions of metals (alloys) as adherend for the test
Adherend

Composition

Ti (ASTM standard Grade 4)

Ti 99.0%, Cmax 0.08%, Hmax 0.015%, Omax 0.40%, Nmax 0.05%, Femax 0.50%

Ni-Cr Alloy

Ni 65%, Cr 22.5%, Mo 9.5%, Nb 1%, Si 1%, Fe 0.5%, Ce 0.5%, Cmax 0.02%

Co-Cr Alloy

Co 61%, Cr 26%, Mo 6%, W 6%, Si 1%, Fe 0.5%, Ce 0.5%, Cmax 0.02%

Au Alloy

Au 83%, Ag 11.97%, Cu 5%, Ir 0.03%

Au-Ag-Pd Alloy

20
15
10
5
0

Au 12%, Ag 49.5%, Pd 20%, Cu 16.85%, (Zn, In, Ga, Ir) 1.65%

In the additional layering of "TWiNY," the amount of ceramics filler contained in the product is large.
Therefore, it is necessary to restore the surface of the unpolymerized layer with the additional layer
solution “TWiNY” Repair Primer after the silane coupling treatment. (On the other hand, "Luna-Wing"
uses organic-inorganic composite filler, so "Luna-Wing REPAIR LIQUID" alone is sufficient.) Therefore,"TWiNY" has one more step of additional layering than "Luna-Wing."
In the case of "Multi Primer REPAIR LIQUID ONE," test specimens were prepared by the following
steps. Multi Primer REPAIR LIQUID ONE was applied on the surface of masked adherend (resin), andthe flowable resin TWiNY FLOW was applied and cured by light. A stainless steel forming rod fortension was then fixed on the cured surface with resin cement (Figure 3). The test specimens were kept
in water at 37 °C for 1 day and then subjected to a test to pull the stainless steel molded rods vertically tothe adhesion surface at a speed of 0.5 mm/min, and the stress at fracture was taken as the tensile bondstrength.

TWINY REPAIR PRIMER＋TWINY REPAIR LIQUID

Multi Primer
REPAIR LIQUID ONE

Figure 4 Tensile bond strength between resin materials

4. Durability
When evaluating the durability of composite materials, a thermal cycle test is commonly performed inwhich alternate immersion in hot water and cold water damages the bonding interface between different
materials due to the difference in thermal expansion coefficient. In the ISO standard (ISO 10477: 2018)
for hard resin for dental crowns, when adhesion to the lower structure without mechanical maintenancesuch as retention beads is indicated, the standard value of the shear bond strength after 5,000 thermal
cycles is 5 MPa or more 9).
For shear tests, a frame with cylindrical holes was used to polymerize body resin in a columnar shape on
the cured surface of opaque resin (Figure 5). The test specimens were kept in water at 37 °C for 1 day,and testing for 5,000 thermal cycles (5-55 °C, 30 sec. each) was carried out. A load was applied to thecylinder of the resin along the adhesion surface at a speed of 1 mm/min, and the stress at break was
defined as the shear bond strength.

∙ In the case of Multi Primer REPAIR LIQUID ONE∙ In the case of Multi Primer LIQUID

Masking

Applying

Applying flowable resin
and light curing

Fixing a stainlesssteel forming rod

Applying

Masking

Applying Opaque (IVO)
and light curing

Applying Opaque (OA3)and light curing

Figure 3 Preparing test specimens for tensile bond strength test
Application of "Multi Primer REPAIR LIQUID ONE" can simultaneously perform silane coupling
treatment and recovery of the unpolymerized layer on the surface. However, as shown in Fig. 4, it was
confirmed that the adhesive strength was equivalent to that of the conventional products 8). By using"Multi Primer REPAIR LIQUID ONE," it will be possible to simplify the additional layering operationof "TWiNY" from 2 steps to 1 step. Of course, it can also be used for "Luna-Wing."

Setting a frame

Filling Body (DA3)and light curing

Removing the frame∙ In the case of Multi Primer PASTE

Masking

Applying
and light curing

Applying Opaque (OA3)and light curing

Setting a frame

Filling Body (DA3)and light curing

Figure 5 Preparing test specimens for shear test

―6―

―7―

Removing the frameLongitudinal shear strength (MPa)As shown in Figure 6 and 7, both "Multi Primer LIQUID" and "Multi Primer PASTE" have alongitudinal shear strength exceeding the standard value of 5 MPa even after the thermal cycle, and resin("TWiNY") was fixed to each adherend. Sufficient durability was thus confirmed. In "Multi Primer
REPAIR LIQUID ONE," the adhesive strength was not measurable because the resin on the adhered side
cracked while the bonded resin remained fixed, before the bond site was broken, but it was confirmedthat the durability is sufficient.

5. Biocompatibility
Cytotoxicity could cause toxicity in tissues, organs, and organisms. Therefore, essential requirements inthe evaluation of biological safety of dental materials include the evaluation of cytotoxicity. In order toevaluate the biocompatibility of "Multi Primer," we conducted cytotoxicity tests using the humanmonocytic leukemia cell line THP.1 cell (distributed by the Department of Oral and Maxillofacial
Surgery, Kochi Medical School, Kochi University).

20
15
10

ISO standard
5 MPa or more

50

Ti Alloy

Ni-Cr Alloy

Co-Cr Alloy

Au Alloy

Au-Ag-Pd Alloy

ZrO2

Figure 6 Longitudinal shear strength of resin after thermal cycle (Multi Primer LIQUID)
Figure 8 Human monocytic leukemia cell line THP.1 cell
Test specimens were prepared as follows. Hybrid resin “TWiNY” was cured to a diameter of 12 mm × a
thickness of 1 mm. Subsequently, another layer of "TWiNY" was additionally built up on it, using "Multi
Primer REPAIR LIQUID ONE." As a reference, a test specimen of “TWiNY" was superposed on anotherlayer of "TWiNY" without "Multi Primer REPAIR LIQUID ONE."Longitudinal shear strength (MPa)

20

15

10

ISO standard
5 MPa or more

50

Ti Alloy

Ni-Cr Alloy

Co-Cr Alloy

Au Alloy

Test specimen
TWiNY

Multi Primer
REPAIR LIQUID ONE

Au-Ag-Pd Alloy

Figure 7 Longitudinal shear strength of resin after thermal cycle (Multi Primer PASTE)
Reference material

Figure 9 Preparation of specimens for cytotoxicity test
Each test specimen was placed in a well of a24-well plate, and 100,000 THP.1 cells were seeded on thespecimen. THP.1 cells were cultured at 37°C for 3 days under 5% CO2 , and then harvested for thefollowing cytotoxicity tests.
Trypan blue dye exclusion test 10)
When cells are damaged by the toxic components, the cell membrane are destroyed. Since cell membrane
exclude dye compounds such as trypan blue, living cells with cell membrane could not be stained,
whereas dead cells without membranes could be stained blue. Therefore, counting living cells and deadcells with a hematocytometer enabled evaluation of the effect of the test specimen on cell proliferationand cell viability.

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―9―

When toxic components are eluted froma test specimen, cells are damaged andcell membranes are destroyed.

THP.1Cell
Test Specimen

WST-8 Cytotoxicity test 11, 12)
In this experiment, the indicator WST-8 was metabolized by living cells to orange-colored WST-8 formazan(λmax = 450 nm). Therefore, quantification of WST-8 formazan by measuring the absorbance at 450 nm
could evaluate influence of the test specimen on the metabolic activity of the cell. The value of absorbanceincreased with the increase in the number of living cells.

Toxic components
NO2

SO3-

SO3N

SO3-

NO2

N

TB

MeO

Dehydrogenase

WST-8

Trypan blue

H
N

N
N+

SO3-

NO2

N
N

N

NO2

MeO

WST-8 formazan

Dead cell
WST-8 is reduced to orange-colored WST-8 formazan by the activity of dehydrogenase in cells.

TB
NO2

Living cell

SO3N
SO3-

Orange: light

H
N
N

NO2

N
MeO

Trypan blue are taken up to the cell with destroyed cell membrane, and stains the cytoplasm.

High toxicity: Amount of formation of
WST-8 formazan decreases due to loweringof metabolic activity of cells.

Figure 10 Principle of Trypan blue dye exclusion test
Cells were mixed with Trypan blue, and living cells and dead cells were then individually counted with ahematocytometer. Cell viability was calculated from the ratio of living cell number to total cell number.

NO2

SO3SO3-

Orange: dark

H
N

N
N

N

NO2

MeO

Low toxicity: Amount of formation of
WST-8 formazan is high due to continuationof metabolic activity of cells.

Figure 12 Principle of WST-8 cytotoxicity test

100

Cells cultured on a test specimen were transferred to wells of a 96-well culture plate, and WST-8 reagent
was then added. After incubation at 37 °C. for 2 hours, the absorbance of WST-8 formazan was measured
at 450 nm.

80
60
40

3.000

20

2.500

0

Multi Primer
REPAIR LIQUID ONE
＋
TWiNY

TWiNY

Figure 11 Proliferation of THP.1 cells cultured on resin
We have reported excellent biocompatibility of the reference material "TWiNY" 2). There were no
significant differences in cell proliferation and cell viability between the test specimen and referencematerial.

Absorbance (450 nm)

Number of cells (×104/mL)

120

2.000
1.500
1.000
0.500
0.000

Multi Primer REPAIR
LIQUID ONE
+
TWiNY

TWiNY

Figure 13 Metabolic activity of THP.1 cells cultured on specimen
In this assay, the test specimen showed equivalent absorbance to the reference material. Therefore, we
considered that there is no adverse effect of "Multi Primer REPAIR LIQUID ONE" on the metabolic
activity of THP.1 cells.

― 10 ―― 11 ―

6. Conclusion

References∙ Adhesion
Each component of "Multi Primer" series was confirmed to have adhesion to the material to be applied.
∙ Durability
It was confirmed that adhesion of each component of the "Multi Primer" series to the object ofapplication was maintained over the long term. The use of "Multi Primer" is thought to greatly reduce therisk of resin falling out of the frame in the oral cavity.
∙ Biocompatibility
A test specimen, in which "TWiNY" was additionally built-up on another layer of "TWiNY" using "Multi
Primer REPAIR LIQUID ONE," showed no cytotoxicity to THP.1 cells. Therefore, we considered thatMulti Primer has excellent biocompatibility.
The cytotoxicity test was carried out in collaboration with the Department of Oral and Maxillofacial
Surgery, Kochi Medical School, Kochi University.

1) ISO 10993-5: 2009，Biological evaluation of medical devices -- Part 5: Tests for in vitro cytotoxicity.
2) Matsuuta R, Mikagi E, Horiguchi K, Anraku T, Yamamoto T: Involvement of residual monomer oncytotoxicity of resin for dental crown. The journal of the Japanese Society for Dental Materials and Devices,29(5): 464, 2010.
3) Matsuuta R, Mikagi E, Anraku T, Yamamoto T: Biological Investigation on the Cytotoxicity of theAdditives in the Hard Resin for Dental Crowns. Journal of the Japanese Society for Dental Materials andDevices, 28: 1-7, 2009.
4) Kadoma Y: Surface Treatment Agent for Dental Metals using a Thiirane Monomer and a Phosphoric
Acid Monomer．Dent. Mater. J., 21(2): 156-169, 2002.
5) Kamada K, Taira Y, Yoshida K, Atsuta M: Effect of Four Silane Coupling Agents on Bonding of Two
Resin-modified Glass Ionomer Cements to a Machinable Ceramic. Dent. Mater. J., 26(2): 240-244,
2007.
6) Kimura H, Kato T, Saigo K, Yamada B, Yamauchi J, Yamamoto S: Evaluation of adhesive strength
between resin and titanium with a primer containing a silane coupling agent. The journal of theJapanese Society for Dental Materials and Devices, 30: 344, 2011.
7) Kimura H, Kato T, Saigo K, Yamada B, Anraku T: Evaluation of the adhesive strength of resins with a
newly developed primer against precious metals, non-precious metals and ceramics. The journal of theJapanese Society for Dental Materials and Devices, 32: 357, 2013.
8) Kimura H, Kato T, Saigo K, Yamada B, Yamauchi J, Anraku T: Development of a repairing liquidcontaining a silane coupling agent for hybrid resins. The journal of the Japanese Society for Dental
Materials and Devices, 31: 469, 2012.
9) ISO 10477: 2018, Dentistry -- Polymer-based crown and veneering materials.

Body of related technological presentations
Monographs submitted
Kato T，Kimura H，Saigo K，Yamada B，Yamauchi J，Anraku T：Effects of a silane coupling agent
on the tensile adhesive strength between resin and titanium. J. Appl. Polym. Sci., 129(5)： 2922-2930，
2013．
Academic conference presentations· 58th Japanese society of dental materials and devices ( 22-23 Oct. 2011)
Kimura H, Kato T, Saigo K, Yamada B, Yamauchi J, Yamamoto S: Evaluation of adhesive strength
between resin and titanium with a primer containing a silane coupling agent (Poster presentation)· 60th Japanese society of dental materials and devices ( 13-14 Oct. 2012)
Kimura H, Kato T, Saigo K, Yamada B, Yamauchi J, Anraku T: Development of a repairing liquidcontaining a silane coupling agent for hybrid resins (Poster presentation)· 61th Japanese society of dental materials and devices ( 13-14 Apr. 2013)
Kimura H, Kato T, Saigo K, Yamada B, Yamauchi J, Anraku T: Development of primer for zirconia
using silane coupling agent (Poster presentation)· 62th Japanese society of dental materials and devices ( 19-20 Oct. 2013)
Kimura H, Kato T, Saigo K, Anraku T: Evaluation of the adhesive strength of resins with a newly
developed primer against precious metals, non-precious metals and ceramics (Poster presentation)10) Correa GT, Veranio GA, Silva LE, Hirata Junior R, Coil JM, Scelza MF: Cytotoxicity evaluation of
two root canal sealers and a commercial calcium hydroxide paste on THP1 cell line by Trypan Blue
assay. J. Appl. Oral Sci., 17(5): 457-461, 2009.
11) Ishiyama M, Miyazono Y, Sasamoto K, Ohkura Y, Ueno K: A Highly water-soluble disulfonatedtetrazolium salt as a chromogenic indicator for NADH as well as cell viability. Talanta, 44(7):1299-1305, 1997.
12) Tominaga H, Ishiyama M, Ohseto F, Sasamoto K, Hamamoto T, Suzuki K, Watanabe M: A
water-soluble tetrazolium salt useful for colorimetric cell viability assay. Anal. Commun., 36: 47-50,
1999.

Previously Published Safety Test Reports
Vol. 1 Pursuing International Standards in Quality and Safety (Dec. 2004)
Vol. 2 ZEO METAL Series Elution Test and in Vitro Cytotoxicity Test ( Jun. 2005)
Vol. 3 Elution Test and in Vitro Cytotoxicity Test of Precious-Metal Alloys and Gold Alloys for Metal Ceramic Restoration Use (Dec. 2005)
Vol. 4 Biological Evaluation of Luna-Wing ( Jun. 2006)
Vol. 5 Report on Physical Properties and Safety of High-Carat Gold Alloys (Oct. 2007)
Vol. 6 Examination of the Biological Impact of the Physical Properties of Dental-Material Alloys and Gold Alloys for Hard Resin and Metal Ceramic Restoration
Use (May 2008)
Vol. 7 Report on the Physical Properties and Safety of the Gold Alloy Nexo-Cast (Oct. 2008)
Vol. 8 Biological Evaluation of the Hybrid Composite Resin, TWiNY ( Jun. 2010)
Vol. 9 Chemical and Biological Characteristics of Precious-Metal Alloys: Elution Characteristics Produced Through Mixture with Titanium (Feb. 2011)
Vol. 10 Physical Properties and Safety of the Precious-Metal Alloy for Metal Ceramic Restoration Use Brightis (Oct. 2011)
Vol. 11 Physical Properties and Safety of the Dental Adhesive, Multi Primer (Mar. 2014)
Vol. 12 Safety of the Dental Pulp Capping Material, TMR-MTA CEMENT ( Jan. 2018)

Editor: Teruo Anraku
Publisher: Takahiko Yamamoto
Date of publication: 20 Mar. 2014
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