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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
31 March 2008 to 25 April 2008
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP compliant, guideline study, available as an unpublished report. Test substance is 84.8 % gold.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Deviations:
no
Principles of method if other than guideline:
Also in accordance with:
ISO 10993-1:2003
ISO 10993-3:2003
ISO 10993-12:2007
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Gold
EC Number:
231-165-9
EC Name:
Gold
Cas Number:
7440-57-5
Molecular formula:
Au
IUPAC Name:
gold(1+)
Details on test material:
Name (as cited in test report): Esteticor®Royal H, dental alloy for metal-ceramic restorations, ISO 22674 and ISO 9693
Batch No: 0000124845
White solid
Composition: 84.8% Au; 8.9% Pt; 2.0% In; 0.2% Fe; 0.2% Ir
Melting Range: 1100-1275°C

Method

Target gene:
Histidine gene
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 100, TA 1535, TA 102, TA 98, TA 1537
Metabolic activation:
with and without
Metabolic activation system:
S9
Test concentrations with justification for top dose:
10, 20, 40, 60, 80, and 100 % concentrations of the test item extract. The 100 % extracts correspond to a surface/volume-ratio of 3 cm2/mL 0.9 % NaCl.
Vehicle / solvent:
distilled water; DMSO
Controls
Untreated negative controls:
yes
Remarks:
untreated
Negative solvent / vehicle controls:
yes
Remarks:
vehicle alone
Positive controls:
yes
Positive control substance:
other: Sodium azide, 4-nitro-o-phenylene-diamene, Methyl methane sulfonate, 2-aminoanthracene.
Details on test system and experimental conditions:
Pre-incubation temperature: 37°C
Period: 60 mins

Incubation temperature: 37°C
Period: 48 hr in the dark
Evaluation criteria:
The mutation factor is calculated by dividing the mean value of the revertant counts through the mean values of the extract vehicle control. A test item is considered mutagenic, if a clear and dose related increase in the number of revertants occurs, and/or a biologically relevant positive response for at least one of the dose groups occurs.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA 100, TA 1535, TA 102, TA 98, TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
No toxic effect of the test item extract noted
No biologically relevant increases in revertant colony number of any of five tester strains observed
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1. TA 98

Treatment Dose/plate Revertant colonies per plate Mutation Factor
    Without activation (-S9) With activation (+S9)
    mean  SD mean  SD (-S9) (+S9)
A. Dest.   25 1.7 34 5 1 1
0.9%NaCl   25 5 33 15.7 1 1
Test Item  10% 32 5.1 35 2.1 1.3 1.1
Test Item  20% 27 5.9 37 1.7 1.1 1.1
Test Item  40% 30 6.7 38 10.8 1.2 1.1
Test Item  60% 30 2.1 32 5 1.2 1
Test Item  80% 35 3.1 43 8.4 1.4 1.3
Test Item  100% 28 4.6 34 4.5 1.1 1
4-NOPD 10 µg 482 41.8 / / 19 /
2-AA 2.5µg / / 2282 129.1 / 68.5

Table 2. T100

Treatment Dose/plate Revertant colonies per plate Mutation Factor
    Without activation (-S9) With activation (+S9)
    mean  SD mean  SD (-S9) (+S9)
A. Dest.   131 7.2 116 12.5 0.9 0.9
0.9%NaCl   150 8.7 132 9.6 1 1
Test Item  10% 123 8.7 98 18 0.8 0.7
Test Item  20% 143 4 111 8.2 1 0.8
Test Item  40% 146 9 116 18.5 1 0.9
Test Item  60% 143 8.3 122 4.5 1 0.9
Test Item  80% 139 2.5 109 7.6 0.9 0.8
Test Item  100% 135 10.4 110 9.1 0.9 0.8
NaN3 10 µg 1032 35.7 / / 6.9 /
2-AA 2.5µg / / 1649 160.5 / 12.5

Table 3. TA 1535

Treatment Dose/plate Revertant colonies per plate Mutation Factor
    Without activation (-S9) With activation (+S9)
    mean  SD mean  SD (-S9) (+S9)
A. Dest.   16 1 15 0 0.6 1.1
0.9%NaCl   25 5 14 3.6 1 1
Test Item  10% 14 4.9 15 1.7 0.6 1.1
Test Item  20% 17 1.2 18 2.5 0.7 1.3
Test Item  40% 17 5.7 12 2.3 0.7 0.9
Test Item  60% 17 3.6 11 2 0.7 0.8
Test Item  80% 19 5.9 14 1.5 0.8 1
Test Item  100% 18 3.5 12 2.6 0.7 0.9
NaN3 10 µg 1190 97.9 / / 47.6 /
2-AA 2.5µg / / 159 15.2 / 11.4

Table 4. TA 1537

Treatment Dose/plate Revertant colonies per plate Mutation Factor
    Without activation (-S9) With activation (+S9)
    mean  SD mean  SD (-S9) (+S9)
A. Dest.   18 3.8 17 3.1 1 1.1
0.9%NaCl   18 3.2 16 5.5 1 1
Test Item  10% 19 2.1 20 1.5 1.1 1.3
Test Item  20% 20 4.4 22 2.3 1.1 1.4
Test Item  40% 17 2.9 17 1 0.9 1.1
Test Item  60% 15 4.2 16 4.7 0.8 1
Test Item  80% 23 4.2 19 2.5 1.3 1.2
Test Item  100% 23 3 21 4 1.3 1.3
4-NOPD 40 µg 140 15.5 / / 7.9 /
2-AA 2.5µg / / 223 13.5 / 14.2

Table 5. TA 102

Treatment Dose/plate Revertant colonies per plate Mutation Factor
    Without activation (-S9) With activation (+S9)
    mean  SD mean  SD (-S9) (+S9)
A. Dest.   177 27.7 267 7.8 0.9 1
0.9%NaCl   188 19 273 16.1 1 1
Test Item  10% 149 24 224 27.4 0.8 0.8
Test Item  20% 172 4 243 11.3 0.9 0.9
Test Item  40% 177 13.5 263 15.6 0.9 1
Test Item  60% 204 13.5 258 6.2 1.1 0.9
Test Item  80% 190 10.8 269 19.5 1 1
Test Item  100% 204 10.2 263 22.5 1.1 1
MMS 1 µg 1769 83.7 / / 9.4 /
2-AA 10µg / / 1270 214.8 / 4.7

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

During the described mutagenicity test, the test item extract did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used. Therefore the test substance is considered to be non-mutagenic in this bacterial reverse mutation assay.
Executive summary:

In a GLP Compliant, Guideline test following standard guidelines (OECD 471 and others), the test substance was found to be non-mutagenic to S. typhimurium TA98, TA 100, TA1535, TA 1573 and TA 102 at concentrations up to 100% using a preincubation method. Tests with and without metabolic activation were conducted.