Introduction
Interproximal reduction, commonly known as IPR, is a routine clinical procedure in orthodontics and clear aligner treatment. It involves the controlled removal of a small amount of enamel between adjacent teeth to create space for tooth movement, improve alignment, manage mild to moderate crowding, or refine tooth proportions.
In aligner and Invisalign cases, IPR is usually planned digitally before treatment begins. However, the clinical result depends on how accurately the planned enamel reduction is transferred into the mouth. This is why IPR should not be viewed simply as “slicing enamel.” It is a measured procedure that requires case selection, controlled instrumentation, cooling, verification, and finishing.
The One Slice IPR Kit is designed to support this clinical workflow by providing FG friction grip IPR burs in different sizes for anterior and posterior interproximal reduction.
Why IPR Is Important in Aligner Treatment
Clear aligners rely on planned tooth movement. When there is insufficient space in the arch, teeth may not track properly, aligner seating may be affected, and treatment progress may become less predictable.
IPR can help create the small spaces needed for planned movement without extraction in selected cases. A 2025 scoping review on IPR with clear aligner therapy reported that IPR is widely used in clear aligner treatment, but also noted variation in clinical protocols, applications, and outcomes. This supports the need for clinicians to follow a clear, measured workflow rather than relying on estimation alone.
Common clinical indications for IPR include:
- Mild to moderate crowding
- Bolton tooth-size discrepancy
- Anterior black triangle management
- Clear aligner space creation
- Contact refinement during orthodontic treatment
- Selected anterior and posterior alignment cases
Because enamel removal is irreversible, IPR should only be performed when properly indicated and planned.
What Recent Research Says About IPR Accuracy
One of the most important clinical issues in IPR is the difference between the amount planned in the digital setup and the amount actually achieved in the mouth.
A 2024 clinical study comparing different IPR methods in Invisalign patients found that motor-driven methods were more effective than hand-operated methods in terms of precision, speed, and patient comfort. The study also showed that accuracy can vary depending on the tooth region and method used.
This is clinically relevant because even small deviations may affect aligner tracking. If too little space is created, the aligner may not express the planned movement properly. If too much enamel is removed, the procedure becomes unnecessarily invasive.
For this reason, IPR should be performed progressively. The clinician should reduce conservatively, verify the created space with an IPR gauge, and continue only when the planned reduction requires it.
Is IPR Safe for Enamel and Periodontal Health?
The safety of IPR depends on diagnosis, enamel thickness, oral hygiene, polishing, and the amount of reduction performed.
A 2025 systematic review on interproximal enamel reduction in orthodontics reported that selected studies did not show negative effects in terms of enamel demineralization, residual irregularities, caries incidence, or periodontal damage. However, the review also emphasized that the quality of available evidence varies and that more high-quality clinical research is still needed.
This means IPR can be a conservative and useful orthodontic procedure when performed correctly, but it should not be treated casually.
IPR should be used carefully or avoided in cases involving:
- High caries risk
- Poor oral hygiene
- Active interproximal caries
- Thin enamel or enamel defects
- Untreated periodontal disease
- Poor patient compliance
- Unclear aligner treatment planning
- Large crowding that requires alternative space management
For dentists and orthodontists, the key is not only whether IPR can be performed, but whether it is clinically justified for that patient.
Why Polishing After IPR Matters
After enamel reduction, the interproximal surface should be finished and polished. This step is important because different IPR methods can leave different levels of enamel roughness.
A 2024 SEM and AFM study found that diamond burs and coarse abrasive strips increased enamel surface roughness more than finer abrasives and polishing methods. The study supports the importance of finishing and polishing after interproximal reduction.
A 2026 Scientific Reports study also found that IPR increased enamel surface roughness, while polishing produced smoother enamel surfaces across tested groups.
From a clinical perspective, this means that IPR should not end once the space is created. The final enamel surface should be refined to support better plaque control, patient comfort, and long-term enamel maintenance.
MR.Bur One Slice IPR Kit: Clinical Purpose and Bur Selection
The MR.Bur One Slice IPR Kit is designed for controlled interproximal reduction in aligner, Invisalign, braces, anterior, and posterior cases. It uses FG friction grip high-speed burs and provides multiple head sizes for different clinical access and reduction needs.
The kit is available in:
-
Trial Set: 7 pcs
Suitable for clinicians who want to test the One Slice IPR system or use a basic IPR selection. -
Full Set: 23 pcs
Suitable for clinics that perform IPR more frequently and require a wider range of anterior, posterior, slicing, and polishing options.
The different bur sizes allow clinicians to approach IPR progressively. A thinner bur may be selected first for initial access or conservative reduction, followed by verification with an IPR gauge before additional reduction is performed.
Which Kaneiko Handpiece Can Be Used With the One Slice IPR Kit?
Because the One Slice IPR Kit uses FG friction grip high-speed burs, it should be used with an FG-compatible high-speed air turbine handpiece.
The recommended Kaneiko handpiece is:
Kaneiko Master Torque Model M9K Friction Grip Air Turbine Dental Handpiece
This handpiece is suitable for IPR because the procedure requires stable bur rotation, controlled contact, water spray cooling, and good clinical visibility.
Other Kaneiko FG high-speed handpieces may also be considered depending on access and case type:
- Kaneiko Standard Head FG Air Turbine Dental Handpiece for routine anterior and posterior cases
- Kaneiko Mini Head FG Air Turbine Dental Handpiece for limited access areas
- Kaneiko Pead Head Super Mini FG Air Turbine Dental Handpiece for smaller mouths or tight posterior access
The important rule is simple: FG IPR burs must be used only with FG-compatible high-speed handpieces. They should not be used in RA, CA, HP, low-speed, or contra angle systems unless the shank system is specifically compatible.
Suggested Clinical Workflow for IPR in Aligner Cases
1. Review the aligner plan
Before performing IPR, check the digital treatment plan and identify the exact contact points, timing, and prescribed reduction amount.
2. Assess enamel and patient risk
Evaluate oral hygiene, caries risk, enamel condition, restorations, periodontal status, and access. IPR should not be performed simply because it appears in a plan if the clinical situation is unsuitable.
3. Select the appropriate IPR bur
Choose the bur based on the planned reduction amount and whether the case involves anterior or posterior access. Start conservatively.
4. Use water spray and controlled pressure
IPR should be performed with light pressure, stable handpiece control, and water spray cooling. Avoid forcing the bur through tight contact areas.
5. Verify with an IPR gauge
After initial reduction, confirm the created space using an IPR gauge. This reduces the risk of both under-reduction and over-reduction.
6. Finish and polish the enamel surface
After the planned space is created, refine the interproximal surface. Research supports polishing after IPR because it improves enamel surface smoothness after reduction.
7. Monitor aligner tracking
After IPR, continue monitoring aligner fit, contact tightness, tooth movement, and patient oral hygiene throughout treatment.
Clinical Takeaway
Interproximal reduction is a small procedure, but it has a significant effect on clear aligner treatment. Recent research supports IPR as a useful orthodontic method when properly planned, but it also highlights the need for accuracy, polishing, and clinical control.
The One Slice IPR Kit supports an organized IPR workflow by providing multiple FG bur sizes for anterior and posterior enamel reduction, along with super fine polishing burs for surface refinement.
For Kaneiko users, the kit can be paired with the Kaneiko Master Torque Model M9K Friction Grip Air Turbine Dental Handpiece or other compatible Kaneiko FG high-speed handpieces. Together, the bur and handpiece selection should support controlled enamel reduction, proper cooling, and predictable clinical handling.
In aligner and Invisalign cases, successful IPR is not about removing enamel quickly. It is about creating the planned space accurately, protecting enamel quality, and supporting predictable tooth movement.
FAQ
What is an IPR bur?
An IPR bur is a dental bur used to remove a controlled amount of enamel between adjacent teeth. It is commonly used in orthodontic and clear aligner cases to create space for tooth movement.
Can the One Slice IPR Kit be used for Invisalign cases?
Yes. The One Slice IPR Kit can be used for Invisalign and other clear aligner cases when interproximal reduction is clinically indicated and planned.
What is the difference between the Trial Set and Full Set?
The Trial Set contains 7 pcs and is suitable for basic testing or limited IPR use. The Full Set contains 23 pcs and provides a wider selection of anterior, posterior, slicing, and polishing burs.
Which handpiece should be used with the One Slice IPR Kit?
The One Slice IPR Kit uses FG friction grip high-speed burs, so it should be used with an FG-compatible high-speed air turbine handpiece. For Kaneiko, the recommended option is the Kaneiko Master Torque Model M9K Friction Grip Air Turbine Dental Handpiece.
Why is polishing needed after IPR?
Polishing helps smooth the enamel surface after reduction. Research shows that IPR can increase enamel roughness, while polishing improves surface smoothness.
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