X2 Endo™ #05 Premolar (UR4)

X2 Endo™ · #05 upper right first premolar · dual hardness

Straightforward until the last four millimetres

What happens when a canal divides after you thought you had finished? The X2 Endo #05 is where a student meets that for the first time. Acadental describe it as a fairly straightforward two-rooted maxillary bicuspid – except that the buccal root diverges apically, with the buccal canal carrying moderate curvature and splitting in the apical 4 mm. The lingual canal has only minor curvature, so the tooth stays fair: one canal to build confidence, one to make the point.

This item: 1 × X2 Endo #05, upper right first premolar (UR4), radiopaque
Made by Acadental, USA · mfr code 3D_AE601X2_05

› Radiographs like an extracted tooth – the apical split is visible on film if the angulation is right, which makes it an unusually good radiography exercise.
› Use a diamond bur – Acadental's instruction for the whole X2 range, because the replicated enamel is comparable in hardness to a natural tooth.
› The other upper premolar – Real-T Endo #12 teaches the ovoid access and perforation risk instead.

Why teach an apical split?
Because a single well-fitting cone in a divided canal is a short fill in disguise, and the film shows it. It is the cleanest argument there is for cone fit and hydraulics.

Isn't #5 the second premolar?
No – in universal notation #5 is the upper right first premolar, UR4 in Palmer. Two roots, buccal and lingual, is the classic upper first premolar form.

Which files for a narrow premolar?
Hand files for the glide path, then a conservative single-file system – RECIPROC Minima is built around narrow preparations.

Complete the system

X2 Endo™ #05 · upper right first premolar UR4 · two roots · buccal canal splits in the apical 4 mm · dual hardness · radiopaque · Acadental · REF ACA3D_AE601X2_05