HELIOFORM GOLD-BASED ALLOY by C. HAFNER GMBH & CO.

Crowns Inlays, Onlays, Overlays, Partial Crowns Telescopes, Cones, Overdentures Direct Technique Double Crown Systems Implant Suprastructures Bridge Structures Baseplates

Detailed descriptions of the above indications can be found in the instructions for Use under 5.1 to 5.7

Device Description

The Helioform System is used to fabricate i. e. inlays, onlays and crowns by a electroforming process. Electroformed gold framework that can be fitted with ceramic facings are an ideal combination of function, esthetic appeal and biocompatibility. The galvano-forming procedure of the Helioform System is as follows:

An electroconductive polyurethane duplicate die is used as a cathode in an electroplating tank. The electrolyte in this tank contains fine gold in solution (HF-Elektrolyt).

When the electric current between the anode and cathode is activated, positively charged gold ions will travel from the electrolyte to the cathode, where they are deposited and form a gold plating.

Galvanoformed parts are produced in Helioform technique using polyurethane dies. The dies are coated with a conductive silver spacer and serves as the cathode of the electroplating circuit.

The electrolyte consists of a non-cyanide gold sulfite solution to which non-cyanide gold concentrate (HF-Goldkonzentrat) is continuously released to replace the gold precipitated on the cathode.

When the electric current is turned on, gold will be deposited on the polyurethane die. The thickness of the laver depends on the duration of the live cycle (approximately 20 um per hour). It can be selected between 200 - 400 um.

The galvanoformed item contains only fine gold with a fineness of 99,99 %. The amount of material required is only about 60 % of what a comparable casting alloy with high gold content would require.

AI/ML Overview

This document is a 510(k) premarket notification for the Helioform dental device. The primary goal of a 510(k) submission is to demonstrate that the new device is substantially equivalent to a legally marketed predicate device. This submission focuses on comparing the physical properties and clinical applications of the Helioform System to the predicate Progold Electrocoping System.

Here's an analysis of the provided text regarding acceptance criteria and study information:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not present explicit "acceptance criteria" in the typical sense of numerical thresholds for a new device to meet. Instead, it relies on demonstrating that the Helioform System possesses comparable or superior physical properties and clinical effectiveness to its predicate device, the Progold Electrocoping System. The "performance" often refers to physical properties of the fine gold and general clinical outcomes.

Feature / Property	Predicate Device (Progold) Performance (where specified)	Helioform Performance	Comparison/Acceptance (Implied)
Material	99.96% electroformed fine gold	99.99% electroformed fine gold	Superior fineness: Helioform has higher fineness (99.99%) compared to Progold (99.96%), which is highlighted as an advantage for biocompatibility. This implicitly surpasses the predicate's performance in this aspect.
Dies used	Stone dies	Polyurethane dies	Difference noted: Helioform uses polyurethane dies, while Progold uses stone dies. The impact on performance is discussed in terms of bond strength and compatibility with porcelains. Both are stated to have "excellent bond strength."
Bond strength to porcelains	Excellent bond strength to conventional porcelains	Excellent bond strength and compatibility to conventional porcelains as well as to low firing porcelains with high coefficient of thermal expansion	Comparable/Extended: Helioform claims "excellent bond strength and compatibility" comparable to Progold's "excellent bond strength" with an added benefit of compatibility with "low firing porcelains with high coefficient of thermal expansion," suggesting an extended range of use without compromising bond strength.
Production Speed/Capacity	16 gold copings in 6-7 hours	10-20 gold copings in 10 hours	Comparable/Slower per coping: Progold produces approximately 2.3-2.6 copings per hour, while Helioform produces 1-2 copings per hour. However, Helioform produces a similar batch size (10-20 vs 16) but over a longer duration. This is presented as a difference, not necessarily an inferior performance that would hinder acceptance in a 510(k) context given other benefits.
Gold Electrolyte content	15 g/l gold content	10 g/l gold content	Difference noted: This is a difference in formulation and process, not directly a performance criterion for the final product in this context.
Concentrate gold content	Not specified	100 g gold content	Difference noted: Similar to electrolyte content, a process difference.
Recovery capabilities	Recovery capabilities of precious metals from solution	Recovery recommendations of fine gold from Electrolyte	Similar functionality: Both systems address precious metal recovery, indicating a comparable aspect of responsible manufacturing, even if the details of the "recommendations" versus "capabilities" differ slightly in phrasing.
Die Divesting/Separation	Stone divesting capability	Thermal separation of polyurethane dies	Difference in method: Both systems have a method for separating the die, suited to their respective die materials. This is a functional difference in the manufacturing process, not a final device performance.
Density (final product)	N/A	19.3 g/cm³	Reported property: This is a specific physical property of the Helioform fine gold, which is generally consistent with pure gold. There's no specific acceptance criterion against a predicate value given.
Melting point	N/A	1064 °C	Reported property: This melting point is characteristic of pure gold. There's no specific acceptance criterion.
Vickers Hardness (after galvanoforming)	N/A	100 HV	Reported property: A measure of the material's hardness. No specific acceptance criterion provided.
Vickers Hardness (after firing on porcelain)	N/A	25 HV	Reported property: Hardness after processing, indicating its workability and durability. No specific acceptance criterion provided.
Grain size (after galvanoforming)	N/A	< 2 µm	Reported property: Indicates a fine-grained structure. No specific acceptance criterion.
Grain size (after firing on porcelain)	N/A	50 µm	Reported property: Grain size after processing. No specific acceptance criterion.
Coefficient of thermal expansion (CTE)	N/A	15.2 µm/m·K (25-500 °C)	Reported property: Important for compatibility with ceramic facings. The document states, "All porcelains which are used together with ceramic alloys with coefficient of thermal expansion between 13.8 and 17.2 um/m·K can be fired on galvanoformed Helioform items," implying that Helioform falls within this acceptable range for dental porcelains. This serves as an implicit acceptance range.
Marginal fit	N/A (predicate comparison mentioned generally in b)(1))	Better than full ceramic or titanium crowns	Claimed superiority: Helioform crowns are stated to have a better marginal fit than full ceramic or titanium crowns. This implies meeting or exceeding the fit of the predicate, though not directly quantified against Progold.
Fracture resistance	N/A (predicate comparison mentioned generally in b)(1))	Better than base metals (including titanium)	Claimed superiority: Helioform crowns show better fracture resistance than base metals. This implies meeting or exceeding the fracture resistance of the predicate.
Biocompatibility	N/A (implied for predicate)	High degree of biocompatibility	Claimed superiority: A specific advantage of Helioform's higher gold fineness (99.99%) is stated to yield better biocompatibility compared to Progold (99.96%).
Precision of fit	N/A	High degree of precision of fit	Claimed advantage: Listed as one of the important advantages.
Pulp protection	N/A	Pulp protection	Claimed advantage: Due to the thin gold jacket leaving more space for ceramic.
Cementability	N/A	Cementability	Claimed advantage: Listed as one of the important advantages.
Esthetics	N/A	Esthetics	Claimed advantage: Listed as one of the important advantages.
Production costs	N/A	Reasonable production costs	Claimed advantage: Listed as one of the important advantages.

Summary of Acceptance Criteria and Device Performance:

The primary acceptance criterion is substantial equivalence to the predicate device, K980613 Progold Electrocoping System. This is demonstrated by:

Similar technological characteristics and intended use.
Comparable or superior physical properties of the final gold structure (especially higher fineness for improved biocompatibility).
Clinical effectiveness for various dental restorations, shown through "numerous in-vitro and clinical studies" that claim advantages in marginal fit, fracture resistance, pulp protection, and overall biocompatibility.

2. Sample Size Used for the Test Set and Data Provenance

Test Set Sample Size: The document does not provide specific numerical sample sizes for "test sets" or the number of samples used in the in-vitro or clinical studies. It uses general terms like "numerous in-vitro studies" and "clinical studies."
Data Provenance: The document implies the studies were conducted to support the Helioform system's development and market introduction. There is no explicit mention of data provenance in terms of country of origin or whether the data was retrospective or prospective. Given the context of a 510(k) from a German company (C. Hafner GmbH & Co. Bleichstraße 13-17 D-75173 Pforzheim), it's highly likely that the supporting data originated from studies conducted in Europe, possibly Germany. The language "Since 1988 intensive efforts were made to introduce galvanoforming to crown and bridge technology. These efforts were preceded by studies..." suggests a prospective and ongoing research and development process.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

The document mentions "A large number of publications" and "numerous in-vitro studies" and "Clinical studies." However, it does not specify the number of experts, their qualifications, or how they established "ground truth" for any specific test set. The claims about marginal fit, fracture resistance, etc., are presented as conclusions from these studies rather than direct expert consensus on a test set.

4. Adjudication Method for the Test Set

No information is provided regarding an adjudication method (e.g., 2+1, 3+1, none) for any specific test set.

5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

No, an MRMC comparative effectiveness study was not done. This document describes a dental material and process (electroforming of fine gold for dental restorations), not an AI-assisted diagnostic or decision-support device that would typically involve human readers and result in an "effect size of how much human readers improve with AI."

6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not applicable. This device is a material/process for fabricating dental prosthetics, not a software algorithm.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

The "ground truth" for the claims in this document would primarily be based on:
- Physical Property Measurements: Direct measurements of density, melting point, hardness, grain size, and coefficient of thermal expansion using standard material science testing methods. These are objective measurements rather than subjective expert consensus.
- In-vitro Study Outcomes: Results from controlled laboratory experiments evaluating fit, marginal leakage, adhesion, stability, and fracture resistance. These would involve objective measurements (e.g., gap width measurement, force at fracture).
- Clinical Outcomes Data: The "clinical studies" mentioned would have gathered data on the performance of the restorations in patients, likely focusing on longevity, patient comfort, biocompatibility, and functional integrity. This would be observed "outcomes data."
- Peer-Reviewed Publications: The repeated reference to "a large number of publications" suggests that the broader scientific and clinical community's findings on galvanoforming technology, including studies from independent researchers, informed the claims.

8. The Sample Size for the Training Set

Not applicable. This document describes a manufactured product and process, not a machine learning model that requires a "training set."

9. How the Ground Truth for the Training Set was Established

Not applicable. As above, there is no training set for this type of device submission.

Summary

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$\mathcal{K}$ 990670

Image /page/0/Picture/2 description: The image shows the logo for C. Hafner. The logo consists of the text "C. HAFNER" in a bold, sans-serif font, with a stylized symbol to the right. Below the name is the text "GOLD- UND SILBERSCHEIDEANSTALT" in a smaller, sans-serif font, set against a black background.

510 (k) Summary

(a) (1) C. HAFNER GmbH & Co Bleichstraße 13-17 D-75173 Pforzheim

Telephone:	07231/920-210
Fax:	07231/920-207

Contact person Dr. Helmut Knosp

1999-01-29 Date:

Name of device: Helioform (a) (2) consisting of HF-Goldkonzentrat HF-Elektrolyt Electrolytic gold
Classification name: gold based alloy
Legally marketed equivalent device: (a) (3) Progold Electrocoping System 510 (k) number: K 980613
The Helioform System is used to fabricate i. e. inlays, onlays and (a) (4) crowns by a electroforming process. Electroformed gold framework that can be fitted with ceramic facings are an ideal combination of function, esthetic appeal and biocompatibility. The galvano-forming procedure of the Helioform System is as follows:

An electroconductive polyurethane duplicate die is used as a cathode in an electroplating tank. The electrolyte in this tank contains fine gold in solution (HF-Elektrolyt).

When the electric current between the anode and cathode is activated, positively charged gold ions will travel from the electrolyte to the cathode, where they are deposited and form a gold plating.

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Image /page/1/Picture/0 description: The image shows the logo for C. Hafner Gold- und Silberscheideanstalt. The logo consists of the company name in bold, sans-serif font, with the words "GOLD- UND SILBERSCHEIDEANSTALT" in a black rectangle below the name. To the right of the name is a stylized graphic of a crucible or other metallurgical vessel.

Galvanoformed parts are produced in Helioform technique using polyurethane dies. The dies are coated with a conductive silver spacer and serves as the cathode of the electroplating circuit.

The electrolyte consists of a non-cyanide gold sulfite solution to which non-cyanide gold concentrate (HF-Goldkonzentrat) is continuously released to replace the gold precipitated on the cathode.

The galvanoformed item contains only fine gold with a fineness of 99,99 %. The amount of material required is only about 60 % of what a comparable casting alloy with high gold content would require. All porcelains which are used together with ceramic alloys with coefficient of thermal expansion between 13.8 and 17.2 um/m·K can be fired on galvanoformed Helioform items. Physical properties of galvanoformed Helioform gold are:

Density:	19,3 g/cm³
Melting point:	1064 °C
Vickers Hardness after galvanoforming:	100 HF
Vickers Hardness after firing on porcelain:	25 HV
Grain size after galvanoforming:	< 2 μm
Grain size after firing on porcelain:	50 μm
Coefficient of thermal expansion:	15,2 µm/m·K(25-500 °C)

(a) (5) Since 1988 intensive efforts were made to introduce galvanoforming to crown and bridge technology. These efforts were preceded by studies of the stability under load and the bond strength of galvano-ceramic crowns. Based on a large number of publications, it may be stated that the range of possible indications has been extended considerably from inlays, crowns, partials to bridges, baseplates, biteplates, telescopic and conical crown systems and implant suprastructures. Even the fabrication of bridges in a single-piece galvanoforming technique has been tested.

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Image /page/2/Picture/0 description: The image shows the logo for C. Hafner Gold- und Silberscheideanstalt. The logo consists of the company name in bold, sans-serif font, with the "C. HAFNER" on the top line and "GOLD- UND SILBERSCHEIDEANSTALT" on the bottom line. To the right of the name is a stylized graphic of a crucible.

(a)(6) Helioform System and Progold Electrocoping System are based on similar technological characteristics.
Differences are as follows:

Progold	Helioform
Using of stone dies excellentbond strength toconventional porcelains	Using of polyurethane diesexcellent bond strength andcompatibility to conventionalporcelains as well as to low firingporcelains with high coefficient ofthermal expansion
99,96% electroformed finegold 16 gold copings in 6-7hours	99,99% electroformed fine fold 10-20 gold copings in 10 hours
Gold Electrolyte with 15 g/lgold content	Gold Electrolyte with 10 g/l goldcontent Concentrate with 100 ggold content
recovery capabilities ofprecious metals from solution	Recovery recommendations of finegold from Electrolyte
Stone divesting capability	Thermal separation ofpolyurethane dies

(b)(1) Numerous in-vitro studies were conducted that looked at fit, marginal leakage, adhesion of bonding materials, stability and fracture resistance as well as on the metal/ceramic interface. What is particularly interesting in this respect is that the marginal fit of Helioform crowns is evaluated as better than those of full ceramic or titanium crowns. Studies of the fracture resistance, too, have shown better results of Helioform crowns than for base metals - including titanium.
(b)(2) Clinical studies have proved that crown and bridge prosthodontics with or without implants fabricated with the galvanoforming process has enormous advantages over other technologies. The thin gold jacket leaves more space for the ceramic layer which permits a more conservative preparation and thus protects the dental pulp better than an all ceramic or conventional metal ceramic restoration.

273611/C/1 8B6B01_

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Image /page/3/Picture/0 description: The image shows the logo for C. Hafner Gold- und Silberscheideanstalt. The logo consists of the company name in bold, sans-serif font, with the words "GOLD- UND SILBERSCHEIDEANSTALT" in a black rectangle below the name. To the right of the name is a stylized image of a crucible.

(b)(3) Inlays, crowns, and bridges produced by galvanic precipitation of fine gold has become firmly established in dental technology. The advantages are obvious. In the Heliform procedure 99,99% fine gold is precipitated in the form of a hard, fine-grained structure. By contrast with casting there are no impurities of porosities. Worked procedures at the dental office and at the dental laboratory either remain practically unchanged, or they are even simplified. A high degree of biocompatibility, precision of fit, pulp protection, cementability, esthetics, and reasonable production costs are the most important advantages of galvanoformed restorations.
The Helioform System is as safe and as effective as the legally marketed Progold Electrocoping System. An advantage of Helioform precipitations is higher fineness of gold (99,99%) which yields to a better biocompatibility.

273611/C/1 8B6B01

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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

APR 2 1999

C. Hafner GmbH & Company C/O Mr. John F. Lemker Bell, Boyd & Llyod Three First National Plaza 70 West Madison Street, Suite 3300 Chicago, Illinois 60602-4207

Re : K990670 Helioform Gold-Based Alloy Trade Name: Regulatory Class: II Product Code: EJT February 26, 1999 Dated: March 2, 1999 Received:

Dear Mr. Lemker

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. ਬੈ substantially equivalent determination assumes compliance with the Good Manufacturing Practice for Medical Devices: General (GMP) regulation (21 CFR Part 820) and that, through periodic GMP inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP requlation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of

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Page 2 - Mr. Lemker

the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 510 (k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling requlation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4692. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note one regulation entitled, "Misbranding by reference fo
the regulation entitled, "Misbranding by reference to information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

Palmeux Coccimite/for

Timothy A. Ulatowski Director Division of Dental, Infection Control, and General Hospital Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Image /page/6/Picture/0 description: The image shows the text "K990670 C. HAFNER GOLD- UND SILBERSCHEIDEANSTALT". The text is in black and is on a white background. The text is arranged in two lines, with the first line containing the number "K990670" and the second line containing the text "C. HAFNER GOLD- UND SILBERSCHEIDEANSTALT".

K990670

Helioform

510 (k) Number:

Device Name:

Indications For Use:

Indicated for fixed and removable dental tooth replacement as follows:

Crowns Inlays, Onlays, Overlays, Partial Crowns Telescopes, Cones, Overdentures Direct Technique Double Crown Systems Implant Suprastructures Bridge Structures Baseplates

Detailed descriptions of the above indications can be found in the instructions for Use under 5.1 to 5.7

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use
(per 21 CFR 801.109)
✓

Over-the-Counter Use

Angela Blackwell for MSR

(Division Sign-Off) Division of Dental, Infection Control, and General Hospital Devices 510(k) Number 490670

Regulation Number and Section

§ 872.3060 Noble metal alloy.

(a)
Identification. A noble metal alloy is a device composed primarily of noble metals, such as gold, palladium, platinum, or silver, that is intended for use in the fabrication of cast or porcelain-fused-to-metal crown and bridge restorations.(b)
Classification. Class II (special controls). The special control for these devices is FDA's “Class II Special Controls Guidance Document: Dental Noble Metal Alloys.” The devices are exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 872.9. See § 872.1(e) for availability of guidance information.