Winnove vs Eztain: Which fixed retainer is best suited for your practice in 2025

Two French digital solutions stand out today in the field of fixed retention to replace aging manual bending. Winnove, founded in Rennes, bends a metallic or TMA wire to the nearest micron using robotics, while eZtain, based in Strasbourg, mills a radiolucent PEEK polymer arch.

This guide offers a factual comparison between Winnove and eZtain so that each orthodontist can choose the solution best suited to their practice.

What is the difference between Winnove and eZtain

Winnove: A Bending Robot for Metallic Wires

Founded in 2020 in Rennes, Winnove receives the patient’s intraoral scan sent by the practitioner. The company then calculates the ideal arch for retention, and a robotic arm bends a high-quality stainless steel or TMA wire with a precision of one-tenth of a millimeter.

Its major assets are its extremely precise occlusal adaptation and its choice of alloys. With Winnove, it is possible to choose the desired material for the patient’s retainer based on their specific needs.

However, the current limitations of steel retainer wire remain. Metallic taste, risk of nickel allergy, risk of imaging artifacts, and above all, a significant risk of breakage or deformation.

Eztain: A Milled PEEK Arch & Fully Digital Workflow

Eztain utilizes a medical PEEK polymer already proven in surgery and implantology. The digital workflow integrates an intraoral scan, digital design, 5-axis CNC milling, and delivery within one week to ensure the proper maintenance of the dental treatment.

Its advantages? High biocompatibility, radiolucency, and especially its aesthetics and comfort, which make it highly favored by patients.
Finally, a five-year internal follow-up reports 0% breakage among eZtain retainer wearers.

Materials and Clinical Impact

Winnove: A Metallic Wire Shaped by Robot

Winnove does not change the material, but rather the shaping. The orthodontic wire remains a metallic alloy (stainless steel as standard, with TMA possible for sensitive patients). The added value of the Winnove solution comes from robotic bending: from the digital setup, the robot bends the wire in 2 dimensions, so that the arch arrives ready to bond with rarely any chairside adjustments.

Clinical Impact

Chairside, the main advantage is procedural: fewer adjustments, a smoother and more reproducible placement session. However, the biological constraints associated with metal (allergies, imaging, sensations) remain unchanged.

Eztain: Milled PEEK Arch

Eztain modifies the material by replacing metal with medical-grade PEEK, milled using CAD/CAM from the STL file. The retainer is adapted in all three spatial dimensions (completely flush against the tooth surface). PEEK is inert (nickel-free), radiolucent (no artifacts in X-rays/MRI), and offers moderate flexibility that better distributes stress. In the mouth, this translates to an absence of metallic taste and a more neutral sensation in daily use.

Clinical Impact

The procedural advantage of the milled component (few adjustments) is found, along with biological benefits inherent to the material: biocompatibility, unrestricted imaging, and reduction of unforeseen appointments related to retention.

Patient Comfort and Perception

Winnove

The Winnove wire arrives already precisely curved, which limits excess thickness and adjustments that could irritate the tongue during the first few days. However, the sensation remains that of a rigid metal: some patients report a slight metallic taste initially and a ‘harder’ perception upon lingual contact.

In practice, acceptance is good among adolescents and adequate among adults, provided that careful attention is paid to the polishing of resins and the refinement of excess adhesive, which are the main causes of friction.

Clinical Impact

Precise positioning reduces adjustments, thus minimizing iatrogenic irritations. Residual complaints are mainly related to the finishing of composites (over-contours, sharp edges) rather than the bending itself.

Eztain

The PEEK arch offers a more neutral sensation in the mouth: no metallic taste, moderate flexibility that softens the perception of tension, and a polished surface that is less prone to catching the tongue. Among adolescents and adults, acceptability is generally high because discretion (shade similar to enamel, radiolucency) and the absence of taste are perceived as significant advantages. Comfort also depends on the design of the pads: a low profile and careful polishing significantly limit friction.

Clinical Impact

Less foreign body sensation and fewer complaints related to lingual irritation when the pads are low and smoothed. Better long-term acceptance among patients sensitive to taste or textures.

Hygiene and Periodontal Health

Winnove

A well-polished metallic wire cleans correctly but remains radio-opaque and can create small retention areas if the pads are over-contoured. In the anterior mandible, the combination of saliva/calcium sometimes promotes tartar on the lingual side, as with any metal retainer. Daily hygiene then relies on a soft brush, floss threaded under the bridge (superfloss), and appropriate interdental brushes. Regarding the periodontium, stability is good if inflammation is controlled; conversely, a rough composite margin harbors plaque and needs to be redone.

In short, there are no additional instructions to provide to your patients regarding the hygiene of a Winnove retainer wire; it is similar to the hygiene of a hand-bent metal wire, with the same limitations.

Eztain

The PEEK surface is smooth and non-metallic. It does not oxidize, release nickel, or attract tartar like some micro-scratched metal areas. Radiolucency does not improve hygiene per se, but it simplifies radiographic follow-up (reading of cervical margins and crests) and avoids any imaging constraints. As with metal, mastery of the pad geometry (low profile, smooth transitions) is crucial for limiting plaque niches. Since the PEEK material is milled to the micron and completely flush against the tooth surface, it retains significantly less dental plaque and prevents many long-term hygiene issues.

And Key Points

• Hygiene primarily depends on the pad design and polishing, regardless of the material.
  
• Winnove: vigilance regarding composite over-contours to avoid plaque niches.
  
• Eztain: perfectly flush against the tooth surface, inert and smooth surface, facilitated radiographic reading, simpler periodontal follow-up.

Digital Workflow and Delivery Times

Winnove

The workflow begins with an intraoral scan and a digital setup. The file is transmitted to Winnove, where the arch is manufactured by robotic bending. The retainer is delivered with a transfer key/guide for indirect bonding: dry positioning, occlusion control, sectional bonding, key removal, bonding of points under the transfer, then finishing.

Regarding lead times, a one-week lead time is most often observed. Placement requires excellent isolation and a rigorous protocol; if the key deforms or the initial adjustment is imperfect, micro-adjustments are necessary.

Clinical Impact

A reproducible but multi-step workflow (fabrication + key + indirect bonding). Chairside time is less predictable, especially if corrections are required on the day of placement. In case of removal for MRI or adhesive failure, re-fabrication requires a new submission (scan/file) and a new guide.

Eztain

The workflow is entirely CAD/CAM: intraoral scan, then STL for immediate PEEK milling and shipment. The retainer arrives ready for indirect bonding, without a bulky key. In practice, lead times are less than one week for most cases.
Radiolucency eliminates the need for removal before imaging.

Clinical Impact

Short chain, few critical steps. On the day of placement, and generally faster than indirect bonding with a key, thanks to the complete seating of the retainer against the tooth surface. Radiolucency eliminates removals for imaging examinations.

Clinical Feedback and Practitioner Perception

Winnove

Feedback primarily highlights the form precision: the metallic arch arrives conforming to the setup, which limits chairside adjustments and secures the bonding protocol. In terms of patient sensation and maintenance, the results remain close to a traditional metallic retainer: adhesion quality and pad design determine long-term stability.

Regarding constraints, practices primarily mention the management of imaging examinations (X-rays, MRI), which may require temporary removal depending on the services. In cases with very pronounced morphologies, the robot may have difficulty performing successive bends, leading to small gaps between the tooth and the wire.

In summary, Winnove’s advantage lies in the reproducibility of bending and the time saved during placement, without changing the nature of the device or its biological limitations.

Eztain

Practitioners emphasize patient comfort (retainer perfectly flush against the tooth surface), radiolucency (no removal before MRI/scan), and a generally shorter placement time due to bonding without a transfer key. Since 2020, field feedback on several thousand retainers reports no reported breakages.

However, precautions are reminded: meticulous surface preparation, low and polished pad profiles, and attention to parafunctional contexts where the design will be adapted. Overall, orthodontists describe a more serene follow-up and more stable productivity in the practice.

FAQ

Winnove or Eztain? My Conclusion

Winnove stands out for the precision of its robotic bending, which ensures faithful adaptation to the digital setup and more reproducible placement. However, it is still a metallic retainer wire: biological constraints remain (metallic taste, possible nickel allergies, imaging artifacts).
Its main advantage therefore lies in procedural optimization — fewer chairside adjustments — versus a heavier logistics burden (transfer key, delivery times) and limited economic visibility due to a lack of clear public pricing.

Eztain, on the other hand, innovates on the material with a medical PEEK arch. Biocompatible and nickel-free, it is radiolucent, causes no metallic taste, and can be placed without a transfer key due to its perfect adaptation. Clinical feedback since 2020 is strong: several thousand placements with no reported breakages, which eases unforeseen management, patient experience, and clarifies long-term ROI.

Ultimately, the choice will depend on the practice’s strategy:

• Winnove is aimed at practitioners committed to the continuity of metal, who seek a more precise and standardized solution for placement, while accepting the material’s limitations.
  
• Eztain will suit those who prioritize clinical innovation, the reduction of emergencies, and ease of follow-up for adult or sensitive patients, with clearer long-term profitability.

Please feel free to read more of our comparisons between eZtain and Memotain as well as our comparisons between Invisalign and Dr. Smile