Every examination needs two instruments: an explorer for caries and margins, and a periodontal probe for pocket depth. Combining them in one double-ended instrument saves a slot in the cassette and an instrument change per patient. This guide explains the graduations, the classic explorer designs, and the combinations available – so you can choose one system for the whole clinic and compare measurements between operators.
Periodontal probe graduations
| Probe | Graduation | Typical use |
|---|---|---|
| CP-12 | 3-6-9-12 mm, colour-banded | general pocket measurement, fast reading |
| CP-15 (UNC-15, North Carolina) | 1–15 mm, every millimetre marked | precise charting, periodontal records |
| CP-2 / CP-2B | 2-4-6-8-10 mm (B = ball end) | general measurement; the ball end is gentle on tissue |
| CP-11 | 3-6-8-11 mm | general measurement |
| CP-18 | 3-6-9-12 mm, long working end | deep pockets |
| Williams | 1-2-3-5-7-8-9-10 mm | the classic Williams pattern |
| WHO (0.5 mm ball end) | black band 3.5–5.5 mm, marks at 8.5 and 11.5 mm | screening (PSR/CPI/BPE) |
| Nabers | curved, colour-banded | furcation involvement |
See all periodontal probes. Choose one graduation for the whole clinic so measurements are comparable between operators.
Explorers
Explorers (also called dental probes or sickle probes) have a fine, sharp tip for tactile examination of tooth surfaces, fissures and restoration margins. The classic designs in the range:
- Explorer 23 – the shepherd's-hook explorer, the most common single-ended design.
- Explorer 17/23 and 17C/23 – double-ended: a straight 17 end for interproximal areas and the 23 hook.
- Explorer 5/9 and 5/8 – double-ended contra-angled explorers for posterior teeth.
- Explorer 8, 9, 6, 17 – single- or double-ended variants; Holst, Weston, 2A/3A, 29 for specific preferences.
See explorers.
Double-ended combinations: explorer + probe
The combinations in the range pair an explorer with a periodontal probe on one handle:
- Explorer 23 + probe CP-12 – the classic examination combination.
- Explorer 23 + CP-12B – with a ball end.
- Explorer 23 + CP-15 – for millimetre charting.
- Explorer 23 + CP-2 / CP-2B – 2 mm graduation.
- Explorer 23 + WHO probe – for screening and recall.
- Explorer 8 + CP-2 / CP-2B / CP-15 / WHO – with the shorter, sturdier explorer 8.
- Explorer 6 + CP-2, 6L + CP-15, 9 + CP-18, Holst + CP-18, Williams + Holst – further variants.
All are listed under explorers and probes.
How to choose
- Routine examination: explorer 23 + CP-12 – the colour bands read fast.
- Periodontal charting to the millimetre: explorer 23 + CP-15.
- Screening (PSR/CPI/BPE): the WHO probe – as a combination or separately.
- Sensitive tissue: the B variants with a ball end.
- Furcations: add a Nabers furcation probe.
Series and handles
Explorers, probes and combinations are available in the ErgoDenta and ErgoLite series and as ErgoTip tips, most with a choice of ErgoX, ErgoX Plus, ErgoLite or ErgoSteel handle. ErgoDenta's article Top 7 hygienist instruments puts the probe in the context of the whole hygiene tray.
Care
Probe tips are fine and easily bent – store them in a cassette with individual slots and inspect the tip and markings at each reprocessing cycle. Reprocess according to the IFU and ergodenta.dk/care.
Reading a probe correctly – design notes
Colour-banded probes (CP-12, CP-11, CP-18) are designed for speed: the eye reads the band edge rather than counting lines. Millimetre-marked probes (CP-15/UNC-15) are designed for precision: every millimetre is visible, which suits full periodontal charting and research. The WHO probe is a screening instrument: its ball end and single black band are meant to answer "is there a pocket deeper than 3.5 mm here?" rather than to measure exactly. Choosing between them is therefore a question of what the clinic records, not of quality.
Ball-end probes
The B variants (CP-2B, CP-12B) and the WHO probe carry a 0.5 mm ball at the tip. The ball reduces the risk of penetrating inflamed tissue and helps the operator feel the base of the pocket and subgingival calculus. Clinics that see many patients with inflamed gingiva often standardise on a ball-end probe.
Explorers: what the numbers mean
Explorer numbers are traditional design codes rather than a system. 23 is the shepherd's hook; 17 is a straight, fine interproximal explorer; 5 and 9 are contra-angled posterior explorers; 8 is a shorter, sturdier hook; 6 is a curved anterior explorer; Holst and Weston are named designs with their own curvature. The double-ended 17/23 remains the most versatile examination explorer, which is why it is also the basis of most combination instruments.
Standardising across the clinic
Because pocket depths are compared over time and between operators, a clinic should use one probe graduation everywhere. The practical way to achieve that is to order the same combination – for example explorer 23 + CP-12 – for every examination cassette, and to use the same colour ring for it so it is recognisable at a glance. See colour-coded rings and sterilisation cassettes.
Where the instruments come from
InstruDent is ErgoDenta ApS' webshop. The explorer and probe range, handle options and reprocessing guidance are published by the manufacturer at ergodenta.dk and ergodenta.dk/care.
Frequently asked questions
What is the difference between CP-12 and CP-15?
CP-12 is marked at 3-6-9-12 mm with colour bands; CP-15 is marked every millimetre up to 15 mm.
What is a WHO probe?
A screening probe with a 0.5 mm ball end and a black band at 3.5–5.5 mm, used for PSR/CPI/BPE screening.
Should the explorer and probe be on one instrument?
Not necessarily – but the combination saves a slot and an instrument change. Both are also available single-ended.
Combinations, single explorers and periodontal probes – ErgoDenta, ErgoLite and ErgoTip.
Shop explorers & probes
Sources and notes
Product range and item numbers: InstruDent/ErgoDenta product records, September 2026. Handle dimensions: ergodenta.dk/ergohandles. Reprocessing: ErgoDenta Care / instructions for use (ergodenta.dk/care). Instrument design and classic areas of use follow standard periodontology and operative dentistry textbooks.
Professional note: instrument selection and treatment technique are clinical decisions. This guide describes instrument design and intended use, not treatment protocols.