(90 days)
Nexus Universal/Nexus Universal Chroma is indicated for cementation of all indirect restorations including ceramic, resin, and metal-based inlays/onlays, crowns, bridges, posts, and veneers*. Additional indications include core build-ups and cementation of crowns to implants.
- Adhesive application on the preparation is required for veneer cementation using Nexus Universal Chroma.
Nexus Universal / Nexus Universal Chroma is indicated for cementation of all indirect restorations including ceramic, resin, and metal-based inlays/onlays, crowns, bridges, posts, and veneers*. Additional indications include core build-ups and cementation of crowns to implants.
- Adhesive application on the preparation is required for veneer cementation using Nexus Universal and Nexus Universal Chroma.
Nexus Universal and Nexus Universal Chroma are offered in paste/paste formulations for use as self-etch, self-adhesive resin cements or as bonded resin cements. These cements are considered permanent and not temporary.
The dual-cure material is packaged in dual barrel syringes with single-use automix tips and optional curved dispensing tips to allow the user to deliver the desired volume of cement directly into the restoration and/or tooth preparation.
Nexus Universal and Nexus Universal Chroma are offered in multiple shades. The difference between Nexus Universal and Nexus Universal Chroma is that Nexus Universal Chroma offers a gel-state color indicator, which visually displays the optimal time to remove the excess cement.
The provided document describes the acceptance criteria and a study to demonstrate substantial equivalence for the dental cement "Nexus Universal" and "Nexus Universal Chroma."
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The document uses the predicate device (Maxcem 2, K073209) as a benchmark for acceptance criteria. The Nexus Universal/Chroma is considered substantially equivalent if its performance is comparable or improved.
| Element | Acceptance Criteria (Predicate: Maxcem 2) | Reported Device Performance (Nexus Universal/Chroma) |
|---|---|---|
| Gel/Set Time (fresh ambient/fresh oral) | ≥ 2'00" / ≤ 3'30" | ≥ 2'00" / ≤ 3'30" |
| Bond Strength to Dentin | 20.35 MPa | 23.05 MPa (Improved) |
| Bonding strength for Post Cementation | 59.68 lbs | 62.34 lbs (Improved) |
| Radiopacity, % aluminum | 280% | 283% (Improved) |
| Film Thickness (μm) | 22 μm | 24 μm |
| Diametral Strength, Mpa (Dual-Cure mode) | 54.8 MPa | 58.1 MPa (Improved) |
| Consistency | 3.00 cm | 3.39 cm |
| Maximum Temperature During Self Curing | N/A (Predicate did not report) | 26.89°C |
| Water sorption | N/A (Predicate did not report) | 33.5 µg/mm³ |
| Color at set time (for Chroma version) | N/A (Predicate did not have a color indicator) | Pass (Visually displays optimal time to remove excess) |
| Biocompatibility | Meets requirements | Meets requirements |
| Shelf Life | 18 months based on real-time data | 18 months based on accelerated data |
2. Sample size used for the test set and the data provenance
The document does not explicitly state the sample sizes for each specific test mentioned (e.g., bond strength, film thickness). It globally refers to the data as "Non-Clinical Performance Data" and "internal performance testing."
- Sample Size: Not explicitly stated for individual tests.
- Data Provenance: The data is described as "internal performance testing." This implies the tests were conducted by the manufacturer, Sybron Dental Specialties. The country of origin is not specified but given the submitter information, it is likely the US. The data is retrospective as it refers to completed tests.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This information is not provided in the document. The tests are non-clinical (laboratory-based) and don't involve human expert assessment for ground truth in the traditional sense of medical image analysis or clinical diagnosis. The "ground truth" for these tests would be the measured physical and chemical properties of the material.
4. Adjudication method for the test set
This information is not applicable as the study is based on non-clinical laboratory tests, not subjective expert assessment requiring adjudication.
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
There was no MRMC comparative effectiveness study done. This device is a dental cement, and the evaluation is based on material properties and non-clinical performance, not on AI-assisted human reading of medical cases.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
This information is not applicable. The device is a dental cement, not an algorithm or AI system.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The ground truth for the non-clinical performance tests would be the measured physical, chemical, and mechanical properties of the dental cement, determined through standardized laboratory testing methods (e.g., ISO standards, FDA guidance). For example, a bond strength measurement has a direct numerical ground truth.
8. The sample size for the training set
This information is not applicable. The device is a physical material (dental cement), not an AI model requiring a training set.
9. How the ground truth for the training set was established
This information is not applicable for the same reason as point 8.
§ 872.3275 Dental cement.
(a)
Zinc oxide-eugenol —(1)Identification. Zinc oxide-eugenol is a device composed of zinc oxide-eugenol intended to serve as a temporary tooth filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or bridges, or to be applied to a tooth to protect the tooth pulp.(2)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 872.9.(b)
Dental cement other than zinc oxide-eugenol —(1)Identification. Dental cement other than zinc oxide-eugenol is a device composed of various materials other than zinc oxide-eugenol intended to serve as a temporary tooth filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or bridges, or to be applied to a tooth to protect the tooth pulp.(2)
Classification. Class II.