Riva Star is a two-component device made up of Riva Star Step 1, containing silver diamine fluoride liquid, and Riva Star Step 2, containing aqueous potassium iodide liquid. Riva Star Step 1 silver diamine fluoride solution is applied to the tooth, immediately followed by Riva Star Step 2 aqueous potassium iodide, which forms an immediate reaction precipitate of silver iodide, thereby reducing tooth sensitivity by physically occluding the open dentinal tubules. Riva Star as well as predicates are liquids or gels that are applied to the teeth using an applicator brush or similar application.

AI/ML Overview

The provided text describes the performance and equivalency of the device "Riva Star" to predicate devices, primarily "Advantage Arrest" and "Super Seal," for the treatment of dentinal hypersensitivity. However, the text does not contain a formal table of "acceptance criteria" and subsequent "reported device performance" against those criteria in a structured format. Instead, it discusses comparability to predicate devices and results from various tests, which indirectly serve as evidence of the device's acceptable performance.

Based on the information provided, here's a structured response outlining the key aspects:

1. Table of Acceptance Criteria and Reported Device Performance

As there is no explicit table of quantitative acceptance criteria provided in the text, I will infer what appears to be the implicit acceptance criteria from the non-clinical and clinical performance testing sections and present the reported performance of Riva Star against those objectives. The primary objective is substantial equivalence to predicate devices.

Implicit Acceptance Criterion	Reported Riva Star Performance
I. Substantial Equivalence to Predicate Devices
1. Similar Indications for Use	Met: Indications for Use are identical to primary predicate device Advantage Arrest ("Treatment of dentinal hypersensitivity. For use in adults over the age of 21."). Differences in phrasing with reference predicates do not change the overall intended purpose.
2. Similar Technological Characteristics/Mode of Action	Met: Both Riva Star and primary predicate Advantage Arrest employ silver diamine fluoride to form precipitates and occlude open dentinal tubules. While Riva Star uses potassium iodide for an immediate silver iodide precipitate, and Advantage Arrest reacts with hydroxyapatite, both achieve tubule occlusion. This is considered substantially equivalent. The mode of action (tubule occlusion) is also similar to the oxalate-based reference predicates.
3. Effective Reduction of Fluid Flow through Dentin (Hydraulic Conductance)	Met: Hydraulic Conductance study demonstrated Riva Star is an effective agent to reduce fluid flow through dentine and is "substantially equivalent to Super Seal in treating dentinal hypersensitivity."
4. Formation of Precipitate to Occlude Dentinal Tubules (SEM)	Met: Scanning electron microscope (SEM) images showed both Riva Star and Super Seal formed a precipitate to occlude the open dentinal tubules.
5. Safety (Biocompatibility/Ion Release)	Met: - Ion Release: Riva Star released less fluoride and silver ions compared to primary predicate Advantage Arrest in a 7-day in vitro study, "demonstrating that Riva Star is as safe as Advantage Arrest." - Biocompatibility: Passed Cytotoxicity (ISO Agarose, ISO Direct contact), Sensitisation (ISO Guinea Pig Maximization Sensitization), Oral Mucosal Irritation (Hamsters, collar method, 7 day), and Oral Acute Toxicity (Mice - 7 day) tests, providing "evidence of biocompatibility." Cytotoxicity results were "equivalent" to Advantage Arrest.
6. Shelf Life	Met: Stability testing established a shelf life of "25 months when stored between 2ºC (35ºF) to 8ºC (45ºF)."
7. Clinical Effectiveness in Reducing Dentinal Hypersensitivity	Met: A double-blind randomized clinical trial showed that "Riva Star was more effective than Super Seal in reducing dentine hypersensitivity after 7 days." This demonstrates clinical effectiveness, furthering the case for substantial equivalence.

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

Non-Clinical Hydraulic Conductance Study: Not explicitly stated how many dentin samples were used.
Non-Clinical In Vitro Ion Release Study: Not explicitly stated how many samples of Riva Star and Advantage Arrest were tested.
Biocompatibility Studies (Animals):
- Sensitization: Guinea Pigs (sample size not specified)
- Oral Mucosal Irritation: Hamsters (sample size not specified)
- Oral Acute Toxicity: Mice (sample size not specified)
Clinical Performance Testing:
- Sample Size: Patients with "recognisable tooth sensitivity on both sides of their upper arch" (Exact number of patients/teeth not specified, but implied to be sufficient for a randomized clinical trial).
- Data Provenance: The study was a "double blind randomised clinical trial on patients." The country of origin is not explicitly stated in the provided text.
- Retrospective or Prospective: Prospective (clinical trial).

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

Clinical Performance Testing: Ground truth (reduction in dentinal hypersensitivity) was established by patient responses recorded on a Visual Analogue Scale (VAS). This indicates self-reported patient pain levels, not expert consensus as the primary ground truth.
Non-Clinical Studies: Ground truth for hydraulic conductance, SEM imaging, ion release, and biocompatibility was established through objective laboratory measurements and biological assays, not expert consensus on images or interpretations.

4. Adjudication Method for the Test Set

Clinical Performance Testing: The primary "ground truth" was patient-reported pain levels via Visual Analogue Scale (VAS). This is a self-adjudication method. The trial was "double blind randomized," suggesting measures were taken to prevent bias in data collection and interpretation. No external expert adjudication method (e.g., 2+1, 3+1) is mentioned for the clinical trial.
Non-Clinical Studies: No adjudication method as these involved objective laboratory measurements.

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 involving human readers or AI assistance was not mentioned. The device, Riva Star, is a dental product (tooth desensitizer), not an imaging or diagnostic AI-powered device that would typically undergo such a study design.

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

Not applicable. Riva Star is a physical product (liquid solution) applied by a clinician, not an algorithm.

7. The Type of Ground Truth Used

Non-Clinical Studies (Hydraulic Conductance, SEM, Ion Release, Stability): Objective laboratory measurements and observations (e.g., fluid flow rate, microscopic images showing precipitate formation, ion concentrations, physical property measurements).
Biocompatibility Studies: Biological assay results (e.g., cell viability, observed irritation/sensitization responses in animal models).
Clinical Performance Testing: Patient-reported outcomes (self-reported pain levels) using a Visual Analogue Scale (VAS).

8. The Sample Size for the Training Set

Not applicable. Riva Star is a physical medical device, not an AI/machine learning algorithm requiring a training set.

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

Not applicable, as there is no training set for this device.

Summary

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Image /page/0/Picture/0 description: The image contains the logos of the Department of Health & Human Services and the Food and Drug Administration (FDA). The Department of Health & Human Services logo is on the left, and the FDA logo is on the right. The FDA logo includes the text "FDA U.S. FOOD & DRUG ADMINISTRATION" in blue.

SDI Limited Rav Cahill Chief Quality and Compliance Officer 3-13 Brunsdon Street Bayswater, Victoria 3153, Australia

Re: K172047

Trade/Device Name: Riva Star Regulation Number: 21 CFR 872.3260 Regulation Name: Cavity Varnish Regulatory Class: Class II Product Code: PHR Dated: March 2, 2018 Received: March 7, 2018

Dear Ray Cahill:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820);

April 11, 2018

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and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Mary-S. Runner -S

forTina Kiang, Ph.D. Acting Director Division of Anesthesiology, General Hospital, Respiratory, Infection Control, and Dental Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K172047

Device Name Riva Star

Indications for Use (Describe) Treatment of dentinal hypersensitivity. For use in adults over the age of 21.

Type of Use (Select one or both, as applicable)
-------------------------------------------------	--

X Prescription Use (Part 21 CFR 801 Subpart D)

| Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary K172047

This 510(k) summary is submitted in accordance with the requirements of 21 CFR 807.92.

1. Submitters information:

SDI Limited

3-13 Brunsdon Street, Bayswater, Victoria 3153, Australia

2. Contact information:

Rav Cahill Chief Quality and Compliance Officer Phone: +61 3 8727 7111 Fax: +61 3 8727 7222 Email:ray.cahill@sdi.com.au

3. Device Information:

Proprietary Name:	Riva Star
Common name:	Tooth desensitiser
Classification Name:	Cavity varnish
Regulation Number:	21 CFR 872.3260
Product Code:	PHR
Classification:	Medical device, Class II

4. Date summary prepared: 2 March 2018

5. Primary Predicate device:

Riva Star is substantially equivalent to predicate device Advantage Arrest (K102973) by Elevate Oral Care, product code PHR.

6. Reference predicate devices:

Super Seal (K120109), D/Sense (K120176), Remesense (K082594), with Product Code LBH.

7. Indications for Use:

Treatment of dentinal hypersensitivity. For use in adults over the age of 21.

8. Purpose and description Device Description and technological characteristics:

Riva Star is a two-component device made up of Riva Star Step 1, containing silver diamine fluoride liquid, and Riva Star Step 2, containing aqueous potassium iodide liquid.

Riva Star Step 1 silver diamine fluoride solution is applied to the tooth, immediately followed by Riva Star Step 2 aqueous potassium iodide, which forms an immediate reaction precipitate of silver iodide, thereby reducing tooth sensitivity by physically occluding the open dentinal tubules.

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Riva Star as well as predicates are liquids or gels that are applied to the teeth using an applicator brush or similar application. With D/Sense, however, the product is in contact with the teeth by foam strips impregnated with the solution.

9. Comparison of technological characteristics:

The fundamental principle and mode of action of Riva Star and the predicate devices in reducing dentinal hypersensitivity is the occlusion of open dentin tubules by the formation of a precipitate.

Both Riva Star and primary predicate Advantage Arrest employ silver diamine fluoride as the main chemical to form the precipitate to occlude the open dentinal tubules. Riva Star, however, also uses a second component, potassium iodide solution, which allows for an immediate reaction precipitate of silver iodide to be formed to occlude the open dentinal tubules. Advantage Arrest, a one component device containing silver diamine fluoride, reacts with the hydroxyapatite of the tooth component. Upon reaction with the silver diamine fluoride, the calcium and phosphate of the hydroxyapatite are converted into calcium fluoride and silver phosphate, respectively to occlude the open dentinal tubules.

With the reference predicate devices Super Seal, D/Sense and Remesense, the oxalate reacts with the dentin calcium to form a deposit of calcium oxalate crystals to occlude the open dentinal tubules and thus reduce tooth sensitivity.

10. Comparison of Indications for Use:

This device is indicated for the treatment of dentinal hypersensitivity, for use in adults over the age of 21.

Its Indications for Use are identical to predicate device Advantage Arrest.

Although Riva Star's indications for use are not identical to the reference predicate devices. the differences in phrasing does not change the overall intended purpose as a tooth desensitiser.

11. Comparison to the Predicate Devices:

A comparison of Riva Star with the predicate devices is as follows:

	Subject device	Primarypredicate device	Referencepredicate device	ReferencepredicatedeviceD/Sense	ReferencepredicatedeviceRemesense
	RIVA STAR	ADVANTAGEARREST	Super Seal
510(k) number	K172047	K102973	K120109	K120176	K082594
Company	SDI Limited	Elevate Oral Care(named as ADPSilver DentalArrest, LLC in510k)	Phoenix Dental,Inc	Centrix, Inc.	Remedent
Classificationname	Cavity varnish	Cavity varnish	Cavity varnish	Cavity varnish	Cavity varnish
Common name	Toothdesensitiser	Toothdesensitiser	Toothdesensitiser	Toothdesensitiser	Toothdesensitiser
Regulationnumber	872.3260	872.3260	872.3260	872.3260	872.3260
ClassificationProduct Code	PHR	PHR	LBH	LBH	LBH
Indications for	Treatment of	Treatment of	Assists in the	Dual-action	Relief of tooth

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Use	dentinalhypersensitivity.For use in adultsover the age of21	dentinalhypersensitivity.For use in adultsover the age of 21	removal of thesmear layer, sealsthe tubules,desensitizes andfunctions as a re-wetting agent.	dentindesensitizerand cavityliner.	sensitivity
Technicalmethod /characteristics:	Silver diaminefluoride andpotassiumiodide form aprecipitate ofsilver iodide toblock opendentinal tubules.	Silver diaminefluoride formsprecipitates withcalcium orphosphate in thedentinal tubules toblock opendentinal tubules	Demineralises theorganic andmineral debris ofthe smear layerand the outermost ring ofperitubular dentin(the very hardmineralized dentinof each tubulecomplex) andrestructures thedemineralizedmaterial as acalcium oxalateprecipitate. Itcreates an acidresistant layerbound both to thesurface as well asinto the dentinaltubules.	Reacts withthe smear laterto precipitatemicro crystalsof calciumoxalate andpotassiumnitrate. Thesecrystalspenetratedeeply into thetubules, andseal the entiredentinalsurface with acontinuous,acid-resistantcomplex.	Potassiumoxalate breaksdown intopotassium andoxalic acid. Theoxalic acidreacts with thecalcium ions toform calcium-oxalate crystals.These crystalsblock the dentintubules, therebyalleviatingdentalsensitivity.
Mode of action	Tubuleocclusion	Tubule occlusion	Tubule occlusion	Tubuleocclusion	Tubuleocclusion
Materialcomposition:	Silverdiaminefluoride,AqueousPotassiumlodide	Silverdiaminefluoride	Oxalicacid,potassium salt	Potassiumbinoxalate,nitricacid,water.	Water, Glycerin,DipotassiumOxalate, Aroma,EDTA, BHT,SodiumHydroxide
Application:	liquid	liquid	gel	liquid	Tray/kit/gel
Rx / OTC	Rx	Rx	Rx	Rx	Rx

12. Non-clinical performance testing:

A Hydraulic Conductance study of Riva Star and Super Seal tooth desensitisers was conducted. The data demonstrated that Riva Star is an effective agent to reduce fluid flow through dentine, and is substantially equivalent to Super Seal in treating dentinal hypersensitivity. Scanning electron microscope (SEM) images showed both Riva Star and Super Seal formed a precipitate to occlude the open dentinal tubules.

A comparative 7-day in vitro fluoride and silver ion release study was conducted on Riva Star and the primary predicate device Advantage Arrest. The data showed that Riva Star released less fluoride and silver ions compared to Advantage Arrest, demonstrating that Riva Star is as safe as Advantage Arrest.

Biocompatibility testing was conducted according to ISO 10993-1:2009 - Biological evaluation of medical devices – Part 1: Evaluation and testing within a risk management process, ISO 7405:2008 – Dentistry – Evaluation of biocompatibility of medical devices used in dentistry, and FDA General Guidance on the Use of International Standard ISO 10993-1 (2016).

The tests carried out for Riva Star and standards applied for each test are as follows: - Cytotoxicity (ISO Agarose, ISO Direct contact) - ISO 10993-5; ISO 7405

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Sensitisation (ISO Guinea Pig Maximization Sensitization) - ISO 10993-10
Oral Mucosal Irritation (Hamsters, collar method, 7 day) - ISO 10993-10
Oral Acute Toxicity (Mice - 7 day) - ISO 10993-11.

Riva Star has limited contact with dentine, being an externally communicating device.

The test carried out for predicate device Advantage Arrest and standards applied is as follows: - Cytotoxicity (ISO Direct contact) - ISO 10993-5; ISO 7405

Riva Star and predicate device Advantage Arrest cytotoxicity testing produced equivalent results. Riva Star testing for irritation, sensitisation and acute oral toxicity provides evidence of biocompatibility.

Stability testing of Riva Star was conducted by evaluating the physical properties of the device to confirm a shelf life of 25 months when stored between 2ºC (35ºF) to 8ºC (45ºF).

13. Clinical performance testing:

A double blind randomised clinical trial on patients with recognisable tooth sensitivity on both sides of their upper arch was performed, with Riva Star applied to the sensitive tooth on one arch, and predicate device Super Seal applied to the sensitive tooth on the other arch, and patients responses were recorded initially and following 1 week, on a visual analogue scale (VAS). The study showed that Riva Star was more effective than Super Seal in reducing dentine hypersensitivity after 7 days.

14. Conclusion:

The information presented in this submission, including compositions for use, mode of action and technological characteristics, biocompatibility, non-clinical and clinical performance testing, establishes that Riva Star is substantially equivalent to the predicate devices.

Regulation Number and Section

§ 872.3260 Cavity varnish.

(a)
Identification. Cavity varnish is a device that consists of a compound intended to coat a prepared cavity of a tooth before insertion of restorative materials. The device is intended to prevent penetration of restorative materials, such as amalgam, into the dentinal tissue.(b)
Classification. Class II (special controls). The device, when it is an external cleaning solution, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 872.9.