# One Curve®

> Single-File Simplicity

- **Manufacturer:** Micro-Mega (COLTENE)
- **Motion:** Continuous Rotation
- **Alloy:** C.Wire NiTi
- **Key feature:** Controlled-memory single-file rotary system with variable cross-section for full canal shaping

## Specifications

| File | Tip (mm) | Taper | Length | Cross-section | Motion | Speed (rpm) | Torque | Role |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 25/.06 | 0.25 | 6% | 21mm, 25mm, 31mm | Variable | Continuous Rotation | 300 | 2.5 Ncm | shaping |
| 25/.04 | 0.25 | 4% | 21mm, 25mm, 31mm | Variable | Continuous Rotation | 300 | 2.5 Ncm | shaping (optional) |
| 35/.04 | 0.35 | 4% | 21mm, 25mm, 31mm | Variable | Continuous Rotation | 300 | 2.5 Ncm | finishing (optional) |
| 45/.04 | 0.45 | 4% | 21mm, 25mm, 31mm | Variable | Continuous Rotation | 300 | 2.5 Ncm | finishing (optional) |

## Protocol

### Glide Path

1. **Initial Exploration** — Create adequate access cavity. Explore canal with manual #08 and #10 K-files to determine canal path and estimate working length.
   - Pre-curve hand files for curved canals
   - Use NaOCl irrigation from the start
   - ⚠ Never force hand files apically
2. **Establish Glide Path** — Create glide path using One G (Micro-Mega glide path file) or manual K-files #08, #10, #15 with crown-down technique. Confirm smooth path to working length. _(File: One G or K-files)_
   - One G (#14, .03 taper) is the dedicated glide path file
   - Manual K-files to #15 is acceptable alternative
   - Crown-down technique: start coronally, progress apically
   - ⚠ Glide path is essential before rotary shaping
   - ⚠ Minimum ISO #10 hand file to working length required

### Shaping

1. **Single-File Shaping - 25/.06** — Use One Curve 25/.06 with direct downward movement to working length in progressive passes. Insert to first resistance point, irrigate, check patency. Re-insert to next resistance point, irrigate. Continue until full working length is reached. _(File: 25/.06 · 300 RPM · 2.5 Ncm · Direct downward (progressive passes))_
   - One file shapes the entire canal — 25/.06 handles most cases
   - Use three progressive waves to reach working length
   - Irrigate with NaOCl between each pass
   - Pre-bend file for difficult access (C.Wire allows pre-bending)
   - ⚠ Do not force the file apically
   - ⚠ Clean flutes after each withdrawal
   - ⚠ Discard after single use — do not reprocess

### Finishing

1. **Alternative: 25/.04 for Narrow/Curved Canals** — If 25/.06 encounters excessive resistance in narrow or severely curved canals, use 25/.04 instead. Same progressive pass technique. _(File: 25/.04 · 300 RPM · 2.5 Ncm)_
   - 25/.04 preserves more dentin in narrow canals
   - Indicated for severe curvature where .06 taper risks transportation
2. **Larger Apical Size (If Needed)** — For larger canals where 25/.06 or 25/.04 is loose at working length, proceed with 35/.04 or 45/.04 for increased apical enlargement. _(File: 35/.04 or 45/.04 · 300 RPM · 2.5 Ncm)_
   - Only use if primary file is loose at working length
   - Gauge with corresponding hand file to verify preparation
3. **Obturation** — Proceed with your standard irrigation and disinfection protocol. Use matching One Curve gutta-percha points for obturation.
   - Matching One Curve GP points available for Classic (25/.06) and mini (25/.04)
   - Use matching One Curve GP points for obturation (per product materials)
   - Standard irrigation protocol

## Clinical Tips

- Same motor settings for all files: 300 RPM, 2.5 Ncm
- C.Wire controlled-memory alloy allows pre-bending for difficult access
- Variable cross-section design for optimized cutting and debris removal
- Single-file system: one instrument shapes the full canal in most cases
- No sucking-in effect during use — smooth cutting action
- Mini variant available with smaller 1mm wire diameter for restricted access
- Compatible with One Flare (coronal flaring) and One G (glide path) ecosystem

## Warnings

- Single-use only — sterile, pre-packaged, do not reprocess
- Contains nickel — do not use on patients with nickel allergy
- Always establish glide path before rotary shaping
- Inspect for deformation before use — discard if any signs of damage
- Do not leave file rotating at working length for extended periods
- Not recommended for severely calcified canals without prior negotiation

## Best for

- single-file rotary simplicity
- controlled-memory flexibility
- pre-bendable for difficult access

## Technical profile

- **Category:** single-file-rotary
- **Heat treatment:** C-Wire — C.Wire controlled-memory heat treatment — superior cyclic fatigue resistance vs conventional NiTi (manufacturer data)
- **Manufacturing method:** ground
- **Pre-bendable:** yes
- **Reuse:** Single-use
- **Motor:** any-rotary
- **Glide path requirement:** optional — One G (dedicated glide path file) or manual K-files (#10-#15) before shaping
- **Canal suitability:** Curvature: mild, moderate, severe; Canal size: narrow, normal; Calcified canals: no; Retreatment: no; Conservative access: yes
- **Matching gutta-percha:** One Curve Gutta-Percha (Classic 25/.06, mini 25/.04, mini 35/.04, mini 45/.04)
- **Matching paper points:** One Curve Paper Points (Classic 25/.06, mini 25/.04, mini 35/.04, mini 45/.04)
- **Content revision:** 2026-02-15

## FAQ

**What alloy is One Curve made from?**

One Curve® is manufactured from C.Wire NiTi with c-wire heat treatment.

**How many files are in the One Curve sequence?**

The One Curve® system includes 4 files: 25/.06, 25/.04, 35/.04, 45/.04.

**What is the One Curve file sequence?**

One Curve® is used in this order: 25/.06 → 25/.04 → 35/.04 → 45/.04. Per-file speed, torque and technique are in the protocol section above.

**What motion type does One Curve use?**

One Curve® uses continuous rotation motion.

**What cases is One Curve best for?**

One Curve® is best suited for: single-file rotary simplicity, controlled-memory flexibility, pre-bendable for difficult access.

**What speed and torque settings are recommended for One Curve?**

Recommended settings: 300 RPM and 2.5 Ncm across the file sequence (refer to official DFU for full per-file parameters).

## References

- [Manufacturer instructions for use (DFU/IFU)](https://www.micro-mega.com/wp-content/uploads/2025/02/IFU-One-Curve-Classic.pdf)

## Related

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_Educational reference for dental professionals. Always confirm settings against the official manufacturer instructions for use before clinical procedures._