Interproximal Reduction (IPR): Safety, Dos & Don’ts 2025
Master safe IPR: enamel limits, disc vs strip, caries risk & bonding hacks. 2025 data, step-by-step protocol + red-flag checklist.
Table of Contents
- Why IPR is still relevant in 2025
- Enamel limits & measurement cheat-sheet
- Instrument options – discs, strips, burs (pros / cons)
- Step-by-step protocol (8 min / arch)
- Safety data – enamel fracture, pulp temp, caries risk
- Post-IPR polishing & remineralisation
- Red-flag checklist – when to skip IPR
- FAQ
- Conclusion & printable gap-gauge chart
(≈ 2 500 words , 3 minutes read time.)
1 | Why IPR is still relevant
Aligner therapy relies on space: mild crowding ≤ 4 mm can be solved by removing 0.3 mm enamel per contact versus extracting premolars. New AI staging plans suggest IPR in 61 % of clear-aligner cases (up from 44 % in 2019).
2 | Enamel limits & measurement cheat-sheet
| Tooth | Mean Proximal Enamel (mm) | “Safe” Removal (mm / side) |
|---|---|---|
| Central incisor | 0.77 | 0.25 |
| Lateral incisor | 0.62 | 0.20 |
| Canine | 0.68 | 0.25 |
| Premolar | 1.12 | 0.40 |
Rule-of-thumb: leave ≥ 0.4 mm enamel; use calliper gauge every pass.
3 | Instrument options 2025
| Tool | Speed | Heat | Reuse | Best for |
|---|---|---|---|---|
| Diamond disc | Fast | High | Autoclave | Posterior strips |
| Single-use disc (0.15–0.3 mm) | Med | Low | Dispose | Anterior aligner cases |
| Hand strip | Slow | None | Single use | Close contacts, final polish |
| Carbide bur | Fast | Med | Autoclave | Black triangles |
Laser enamel micro-ablation trials exist but not FDA-cleared (yet).
4 | 6-Step Protocol (chair-time 8 min / arch)
- Diagnostic: measure Little’s Index, plan 0.1 mm passes.
- Isolation: cheek retractor + saliva ejector.
- Mark & open contact: separator saw 0.1 mm.
- Disc pass: oscillating disc 10 k rpm, water spray, 2 s contact.
- Gauge: calliper; if < planned, repeat pass.
- Polish & fluoride: 30 µm strip then 0.2 % NaF foam 60 s.
Total heat rise ≤ 3 °C; pulp necrosis risk < 0.1 %.
5 | Safety Data 2019-2024
| Risk Metric | Result | Note |
|---|---|---|
| Enamel fracture ↑ | –20 % if pre-scored with saw | RCT 2023, n = 60 |
| Pulp temp rise | +1.8 °C disc vs 3 °C bur | < 5.5 °C safe threshold |
| Crestal bone loss | +0.11 mm at 12 mo | Clinically trivial |
| Caries incidence | 0.25 % vs 0.49 % contralateral (ns) | Polish critical |
Systematic review (2024, n = 1 146 contacts) confirms no long-term sensitivity or recession increase.
6 | Post-IPR Polishing & Remineralisation
- Use 30 µm diamond strip until mirror-shine; roughness Ra < 0.2 µm.
- Apply 5 % NaF varnish or CPP-ACP mousse for 3 min.
- Instruct patient to avoid acidic drinks 24 h.
- Reassess at next change-tray visit; if rough edge detected, micro-polish.
7 | Red-Flag Checklist — skip IPR if…
❌ Short clinical crown < 9 mm
❌ Poor oral hygiene (O’Leary > 20 %)
❌ Enamel decalcification (white spots)
❌ Root proximity < 0.3 mm on CBCT
❌ Crowding > 6 mm → consider extraction
8 | FAQ
Can IPR close black triangles?
Yes—remove 0.1–0.2 mm each side of contact, erupt flossing point; success 78 %.
Does AI over-plan IPR?
Often; manually cap at 0.5 mm per contact regardless of AI suggestion.
Can I use prophy cup to polish?
Better: 30 µm strip; cup leaves grooves.
9 | Conclusion & Gap-Gauge Chart
IPR remains a safe, minimally invasive space-creating tool—if enamel limits, heat control and polish steps are respected. Download our one-page gap-gauge chart to standardise your team.
Disclaimer
This article has been compiled and presented by Dentovex Orthodontics – Research Group for educational purposes only. It is not intended as medical advice and should not replace a face-to-face consultation with a licensed dentist, orthodontist, or other qualified healthcare professional. Always seek the advice of your own clinician regarding any questions or concerns about diagnosis, treatment, or health conditions.
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