File Doctor by ByteSized Dentistry

Change one thing about a rotary file and see how it ripples into the clinic.

1 · The canal

low strainhighnear fractureoriginal canal

2 · Design the file

Start from

3 · What happens clinically

/ 100 overall in this canal

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Cause & effect · what one notch of each choice does

Step each choice

Numbers are the change in each outcome's 0–100 score; green = better for the patient. Tap a cell for the reason.

A file system is a sequence of files

Shared by every file

The system, clinically

/ 100 overall

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File by file

Breakage is set by the weakest file, centring by the stiffest, time is the sum, and the final file decides the shape.

Each card is one "what if". The numbers are live from the same model, in the canal shown. Open any of them in Design to keep exploring.

How the numbers are made: bending strain = file radius ÷ curve radius at a curve 5 mm from the apex; fatigue life ∝ strain⁻², scaled by alloy (classic NiTi 1×, M-Wire 1.8×, Gold/Blue 2.6×, CM/EDM 5×) and motion (reciprocation 1.8×), anchored to ≈400 cycles for a ProTaper Universal F2-style file in a 60°, 5 mm-radius canal. Torsional strength ∝ D3², anchored to ≈1.2 N·cm; demand grows with wall engagement and screw-in. Stiffness ∝ E·d⁴. Files are retired at half their predicted fatigue life (15 s per canal) and stop widening at 1.2 mm. Reference files and systems are "-style" approximations from public descriptions, not manufacturer data. For teaching and concept design, not clinical guidance.