PEEK scan bodies more accurate than titanium, sterilisation does no harm

The scan body material mattered more than the number of sterilisations

A digital impression on implants stands or falls on one small part — the scan body. If that component deforms over time or starts seating differently in the implant interface, the error is carried onward into the model, into the abutment and into the passive fit of the finished restoration. The question that troubles anyone using the same components for months is simple: how many times may I autoclave them before they become unreliable?

The researchers around Bige Koç Ateş tested exactly that. They took monoblock scan bodies made of titanium and of PEEK, paired them into ten study groups and first scanned each pair with an intraoral scanner to obtain a reference scan. Then came 30 cycles mimicking daily practice — tightening, loosening, sterilisation — with a control scan after every five cycles, that is six scans per group. From the scans they calculated linear deviations along three axes, angular deviation and the three-dimensional Euclidean distance from the reference.

The result is twofold and somewhat unexpected. The number of cycles played almost no role: neither titanium nor PEEK wore measurably over 30 repetitions (p > 0.05). What did separate the groups was the material — titanium scan bodies showed significantly larger deviations along the X and Z axes and in the overall three-dimensional distance than PEEK (p < 0.05). The authors conclude that PEEK produced more accurate and more consistent digital scans.

Limitations

This is a laboratory model with a small number of samples and ten study groups, without clinical variables such as saliva, limited mouth opening or difficult access in the distal segment; what was measured is the repeatability of a component, not the survival of prosthetic restorations.

For your practice

• If you are choosing between monoblock scan bodies, PEEK was the more consistent choice for the digital impression in this measurement.
• The fear of wear from autoclaving is not confirmed here — over 30 cycles deviations did not accumulate with either material.
• Titanium scan bodies are not unusable, but with a larger number of implants and long spans it is worth verifying the scan with a control measurement before the framework is made.