EN ISO 8325:2023/prA1:2025

Dentistry - Test methods for rotary instruments - Amendment 1 (ISO 8325:2023/Amd 1:2025)

Zahnheilkunde - Prüfverfahren für rotierende Instrumente - ÄNDERUNG 1 (ISO 8325:2023/Amd 1:2025)

Médecine bucco-dentaire - Méthodes d'essai pour instruments rotatifs - Amendement 1 (ISO 8325:2023/Amd 1:2025)

Zobozdravstvo - Preskusne metode za vrtilne instrumente - Dopolnilo A1 (ISO 8325:2023/Amd 1:2025)

General Information

• Status: Not Published
• Publication Date: 17-Aug-2026
• ICS: 11.060.20 - Dental equipment
• Technical Committee: CEN/TC 55 - Dentistry
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 15-Dec-2025
• Completion Date: 15-Dec-2025
• Ref Project: SIST EN ISO 8325:2023/oprA1:2025 - Dentistry - Test methods for rotary instruments - Amendment 1 (ISO 8325:2023/Amd 1:2025)

Relations

• Amends: EN ISO 8325:2023 - Dentistry - Test methods for rotary instruments (ISO 8325:2023)
• Effective Date: 04-Oct-2023

Overview

EN ISO 8325:2023/prA1:2025 (Dentistry - Test methods for rotary instruments - Amendment 1) updates measurement and test procedures for dental rotary instruments. This amendment clarifies referenced standards, refines how shank dimensions and markings are measured, and revises the procedures and formulas used to determine neck strength and run‑out tests. The changes support consistent test execution, product safety evaluation and regulatory alignment for manufacturers, test labs and conformity assessors.

Key Topics

• Updated references: Clause 3 now directs users to ISO 1797, ISO 1942, ISO 21850-1 and additional terms and definitions used in the document.
• Shank dimensions (5.5 series):
  • Shank diameter shall be determined in accordance with ISO 1797.
  • Shank length is defined as the distance from the end of the shank to the shortest beginning of the neck, or to the start of the working part if no neck is present.
  • Markings (e.g., incisions or indentations for colour coding) are considered part of the shank/fitting length if the marking outer diameter is smaller than the shank diameter. If the marking outer diameter exceeds the shank diameter, measurement locations move to the start of the marking.
• Run‑out / dynamic test update (5.11.3.1):
  • Apply a load F = 2 N for 5 s; if the test piece does not break, re‑measure run‑out (t5) after the load application.
• Neck strength calculation (5.11.4):
  • For rotary instruments where L > 5D, the test force is calculated with the specified formula in the amendment (expressed using parameters F, k, D and L). The document defines variables and notes the deduction in Annex A.
  • The k‑factor (shape and material) is specified in the relevant instrument standard (example given: k = 81,8 N/mm for diamond instruments in ISO 7711).
  • A maximum test force limit of 60 N is enforced; manufacturers note that for certain instruments (e.g., diamond) clinical forces are much lower and recommended values (2 N) may apply.

Applications

This amendment is directly applicable to:

• Test laboratories performing mechanical and dimensional tests on dental rotary instruments.
• Manufacturers updating test procedures and declarations for product safety and conformity.
• Regulatory reviewers and procurement teams requiring standardized methods for durability, run‑out and neck strength assessment.

Benefits include improved repeatability of measurements, clearer interpretation of shank/marking geometry, and a harmonized approach to calculating test forces for neck strength evaluations.

Related Standards

• ISO 1797 - referenced for shank diameter determination
• ISO 1942 and ISO 21850-1 - referenced for terms and definitions
• ISO 7711 - cited as an example source for k‑factor guidance for diamond instruments

For implementation and official interpretation, consult the full EN ISO 8325:2023/prA1:2025 amendment text and the referenced standards. Feedback or patent notifications should be directed to the responsible national body or ISO secretariat as indicated in the published draft.

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2025
Zobozdravstvo - Preskusne metode za vrtilne instrumente - Dopolnilo A1 (ISO
8325:2023/Amd 1:2025)
Dentistry - Test methods for rotary instruments - Amendment 1 (ISO 8325:2023/Amd
1:2025)
Zahnheilkunde - Prüfverfahren für rotierende Instrumente - ÄNDERUNG 1 (ISO
8325:2023/Amd 1:2025)
Médecine bucco-dentaire - Méthodes d'essai pour instruments rotatifs - Amendement 1
(ISO 8325:2023/Amd 1:2025)
Ta slovenski standard je istoveten z: EN ISO 8325:2023/prA1:2025
ICS:
11.060.25 Zobotehnični instrumenti Dental instruments
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
Amendment
ISO 8325:2023/
DAM 1
ISO/TC 106/SC 4
Dentistry — Test methods for rotary
Secretariat: DIN
instruments
Voting begins on:
AMENDMENT 1
2025-04-10
Médecine bucco-dentaire — Méthodes d'essai pour instruments Voting terminates on:
rotatifs 2025-07-03
AMENDEMENT 1
ICS: 11.060.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO 8325:2023/DAM 1:2025(en)
DRAFT
ISO 8325:2023/DAM 1:2025(en)
Amendment
ISO 8325:2023/
DAM 1
ISO/TC 106/SC 4
Dentistry — Test methods for rotary
Secretariat: DIN
instruments
Voting begins on:
AMENDMENT 1
Médecine bucco-dentaire — Méthodes d'essai pour instruments Voting terminates on:
rotatifs
AMENDEMENT 1
ICS: 11.060.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO 8325:2023/DAM 1:2025(en)
ii
ISO 8325:2023/DAM 1:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different type
...