Diagnostik · Ratgeber ·

Dental Explorers: Types and Use in Diagnostics

The dental explorer is part of the basic equipment for every examination. With its fine tip you can feel restoration margins, calculus and irregularities on the tooth surface. Explorers come in many designs that differ in curvature, shank length and tip. This guide explains the common explorer types – from the No. 23 shepherd's hook to the DG 16 endodontic explorer –, their use in diagnostics, current guidance on caries assessment, and materials and care. How periodontal probes with a millimetre scale work is explained in our guide Periodontal probes compared.

Explorer No. 23, single-ended
Pictured: Explorer No. 23, single-ended

Key points at a glance

  • Dental explorers are pointed tactile instruments without a scale. Periodontal probes are blunt and carry a millimetre scale.
  • The No. 23 explorer (shepherd's hook) is the most common explorer design.
  • For proximal surfaces and subgingival calculus there are designs such as the No. 17, pigtail/cowhorn explorers or the 11/12.
  • The DG 16 is the standard explorer in endodontics for locating root canal orifices.
  • Fissures and demineralised enamel are not probed with pressure: a sharp explorer can irreversibly damage weakened enamel.
  • Explorers are held with a light grasp; only the terminal 1–2 mm of the tip is used for exploring.

What is a dental explorer?

A dental explorer consists of a handle, a shank and a slim working end with a fine tip. The thin working end transmits the finest vibrations to the fingers. This lets you feel whether a surface is smooth or whether there is a margin, a ledge or a deposit. This tactile sensitivity only works with a light grasp: holding the explorer firmly dampens the vibrations and you feel less.

A dental explorer differs clearly from a periodontal probe. The periodontal probe has a blunt tip and a scale; it measures probing depths. The explorer is pointed, has no scale and is used for tactile examination. Many instruments combine both on one handle.

Explorers are available single-ended (often “SE” in catalogues) and double-ended (“DE”). Double-ended explorers carry two mirror-image working ends, two different explorer designs, or an explorer and a periodontal probe.

The main explorer types

No. 23 explorer (shepherd's hook)

The No. 23 is the most common explorer design. Its working end is hook-shaped, like a shepherd's crook. Manufacturers describe it as the typical explorer for caries detection – with the limitations described below. Today it is used mainly to examine tooth surfaces and check filling and crown margins. In our shop you will find the explorer No. 23, single-ended.

No. 17 explorer

The No. 17 explorer reaches proximal surfaces well and is suitable for detecting subgingival calculus. In common manufacturer catalogues it is combined with the No. 23 shepherd's hook as the double-ended explorer No. 5, for example the double-ended explorer No. 5.

No. 6, No. 8A and double-ended explorer 23/6

The No. 6 is another common basic design. It is available on its own as the explorer No. 6, single-ended or together with the shepherd's hook as the double-ended explorer 23/6. With the double-ended version you have two explorer designs at hand during the examination without changing instruments. Another single-ended variant is the explorer No. 8A.

Pigtail and cowhorn explorers

Pigtail and cowhorn explorers (for example No. 2 and 3CH) have paired, strongly curved working ends. The curvature makes it easier to access proximal surfaces. They are used mainly in a healthy, shallow sulcus.

11/12 and No. 3A explorers

The 11/12 explorer is area-specific, modelled on Gracey curettes. With its long, multi-angled shank it also reaches deep pockets in the posterior region and is used to detect calculus on the root surface. The No. 3A is a long, slightly curved explorer for complex anatomy.

DG 16 endodontic explorer

The DG 16 is the standard explorer in endodontics. It is double-ended, with two long, slim and sharp working ends angled differently. This lets it reach into the access cavities of upper and lower molars and locate the canal orifices on the pulp chamber floor. In our shop: endodontic explorer DG 16, double-ended.

Combination instruments with periodontal probe

Combination instruments carry an explorer, usually the No. 23, on one end and a periodontal probe on the other. This lets you check margins and measure probing depths without changing instruments. In our shop you will find the combination instrument explorer 23 / periodontal probe PCP 12, the combination instrument explorer 23 / periodontal probe UNC 15 and the explorer 23 / PCP-11.5-B. For furcations there are dedicated curved probes such as the Nabers furcation probe PQ2N.

Use in diagnostics

Caries assessment: no pressure in fissures

In the past, an explorer “sticking” in a fissure was regarded as a sign of caries. This method is no longer recommended. A sharp explorer can irreversibly damage demineralised enamel that could still remineralise, and can thus cause cavitation. Caries is therefore assessed mainly visually on the cleaned and dried tooth surface, supplemented by radiographs. If tactile examination is used, it is done with light pressure or with a blunt ball-ended probe, as also used in visual classification systems such as ICDAS.

Filling and crown margins

At restoration margins, the explorer remains an important aid. Guide the tip with light pressure across the junction between tooth and restoration. This lets you detect overhangs, ledges and marginal gaps. The No. 23 explorer and the double-ended explorer 23/6 are commonly used for this.

Calculus detection

Before and after scaling, use the explorer to check whether the root surface is smooth. Designs such as the No. 17, the 11/12 or the No. 3A are suitable for proximal surfaces and deeper pockets. Hold the explorer so lightly that a tap on the handle would move it, and adapt only the terminal 1–2 mm of the tip. Which instruments then remove calculus is explained in our guide Scaler or curette?.

Endodontics

In endodontics, the DG 16 is used to locate the canal orifices on the pulp chamber floor and to confirm suspected orifices.

Overview: explorer types and uses

Explorer type Design Typical use
No. 23 (shepherd's hook) Hook-shaped Tooth surfaces, filling and crown margins
No. 17 Angled working end Proximal surfaces, subgingival calculus
No. 5 Double-ended, 17/23 in common catalogues Combined proximal and surface examination
No. 6 / 23/6 Single-ended or double-ended with No. 23 Examination, restoration margins
Pigtail / cowhorn (e.g. No. 2, 3CH) Paired, strongly curved Proximal surfaces, shallow sulcus
11/12 Area-specific, long angled shank Deep pockets, posterior calculus
No. 3A Long, slightly curved Root surfaces with complex anatomy
DG 16 Double-ended, long, slim, sharp Endodontics: locating canal orifices
Explorer 23 + periodontal probe Double-ended, pointed + blunt with scale Checking margins and measuring probing depths

The numbers come from catalogue systems that have evolved over time and are not identical across all manufacturers. Always check the image and the details in the product description. You will find all models in our probes and dilators category, and the endodontic explorer also in the endodontics category.

Materials and care

Dental explorers are usually made of stainless steel. After every use they are cleaned, disinfected, inspected and sterilised, usually with steam at 134 °C. Check the tip with a magnifier: a bent or worn tip transmits less information and should be replaced. Protect the fine tips during storage and sterilisation, for example in instrument cassettes. Detailed advice is given in our guide instrument care and reprocessing.

Looking for information on extraction forceps? Read our guide Extraction forceps: which forceps for which tooth?.

Matching products in our shop

Matching categories

Frequently asked questions

What is the difference between a dental explorer and a periodontal probe?

The explorer is pointed and has no scale; it is used to feel surfaces, margins and calculus. The periodontal probe is blunt and carries a millimetre scale; it measures probing depths.

What is the No. 23 explorer used for?

The No. 23 shepherd's hook is the most common explorer. It is used mainly to examine tooth surfaces and check filling and crown margins. It is not used with pressure in fissures.

Can fissures be checked for caries with an explorer?

Not with pressure. A sharp explorer can damage demineralised enamel. Visual assessment of the cleaned, dried tooth surface is recommended, supplemented if necessary by a blunt ball-ended probe and radiographs.

What is a DG 16 used for?

The DG 16 is a double-ended endodontic explorer. Its long, sharp working ends are used to locate root canal orifices on the pulp chamber floor.

What do SE and DE mean for explorers?

SE stands for single-ended, with one working end. DE stands for double-ended, with two working ends.

Which explorer is suitable for detecting calculus?

For proximal surfaces and subgingival calculus, the No. 17, the 11/12 or pigtail and cowhorn explorers are often used. A light grasp is important so that the fine vibrations remain perceptible.

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