Explorer

Describe the uses and functions of the dental explorer as an assessment instrument

Used to detect and assess the texture and characteristics of tooth surfaces for presence of calculus deposits, decalcified and carious lesions, dental anomalies, and anatomic features like grooves, curvatures, or furcations.

Supragingival

Use of an instrument coronal to (above) the gingival margin.

Subgingival

Use of an instrument apical to (beneath) the gingival margin.

Explorer handle

Lightweight (15 g), textured (knurling), and large diameter (10 mm).

Explorer shank

Simple or complex, flexible, and circular in cross-section.

Flexible shank

Has a thinner diameter that flexes when lateral pressure is applied against the shank—ideal for calculus detection.

Purpose of flexible shank

Detects subgingival calculus; vibrations are transmitted from the working end through the shank to the clinician’s fingers.

Functional shank

Begins where the working end meets the shank and extends to the last bend nearest the handle.

Terminal shank

Portion of the functional shank nearest to the working end; used to visually identify the correct working end—should be parallel to the tooth surface.

Working end

Extends from the tip of the working end to the first bend of the shank; circular cross section, flexible, may be paired or unpaired, 1–2 mm tip used for adaptation.

Face of working end

The surface that faces the tooth.

Back of working end

Rounded to push gingiva out of the way.

Lateral side

Adapted to the tooth surface.

Tip

The leading 1–2 mm of the working end that glides along the tooth; the point is not directed into the tooth or gingiva.

Simple shank with short functional length

Supragingival use on anterior teeth.

Simple shank with long functional length

Subgingival use on anterior teeth.

Complex shank with short functional length

Supragingival use on posterior teeth.

Complex shank with long functional length

Subgingival use on posterior teeth.

Shepherd Hook

Simple shank, slightly larger diameter, slightly less flexible; used supragingivally to assess sealant retention and restoration margins.

Orban Explorer

Simple, flexible, circular cross-section, 90° bend to lower shank; used for anterior teeth and facial/lingual surfaces of posterior teeth; works well in narrow pockets.

11/12 Explorer

Circular cross-section, very flexible, 90° bend to lower shank, long complex shank for posterior and anterior teeth; used subgingivally to assess tooth and root surfaces.

Assessment (exploratory) stroke

Very precise, light, flowing stroke of short to moderate length; many overlapping, controlled strokes used.

Tactile sensitivity

Ability to detect calculus deposits through vibrations from the explorer tip to the handle and fingers; enhanced by flexible shank and light grasp.

Adaptation of the explorer

The first 1–2 mm of the lateral surface should be in contact with the tooth; requires rolling or pivoting at line angles to maintain contact.

Incorrect adaptation

Leads to failure to detect calculus or laceration of tissue.

Insertion

Action of moving the working end beneath the gingival margin into the sulcus or pocket.

Activation

Movement of the explorer to produce a stroke; accomplished through wrist or digital motion activation.

Correct grasp

Relaxed grasp with middle finger resting lightly on shank.

Lateral pressure

Feather-light pressure against the tooth surface.

Stroke characteristics

Fluid, sweeping, multidirectional strokes with wrist or digital activation.

Common errors

Tight "death grip," applying pressure with the middle finger, or using too much force.

Correct working end selection

Observe lower shank in relation to distal surface of a premolar—terminal shank should be parallel; functional shank should go up and over the tooth.

Incorrect working end

Terminal shank crosses the facial surface like a seatbelt.

Stroke directions—Oblique strokes

Used on facial and lingual surfaces of anterior and posterior teeth; angled toward junctional epithelium.

Stroke directions—Vertical strokes

Used on all surfaces of anterior teeth and mesial/distal surfaces of posterior teeth; tip not pointed toward JE.

Stroke directions—Horizontal strokes

Used at line angles, on facial/lingual surfaces of anterior teeth, and in furcation areas; short, tiny strokes around the line angle.

Probe vs Explorer comparison—Probe

Measures pocket depths; Explorer

Supragingival calculus

Coronal to gingival margin; visible irregular deposits; minerals from saliva; white, beige, or stained; chalky when dried with air.

Subgingival calculus

Apical to gingival margin; derived from gingival crevicular fluid; not visible; flattened by gingival pressure; can appear black due to hemoglobin.

Calculus types—Spicules

Isolated, minute deposits.

Calculus types—Nodule

Larger, crusty deposit.

Calculus types—Ledge

Ridge running parallel to gingival margin.

Calculus types—Ring

Ridge encircling the tooth.

Calculus types—Veneer

Thin, flat coating.

Calculus types—Spur

Long, narrow deposit oblique to root surface.

Calculus types—Residual

Calculus left after scaling.

Caries detection purpose

Identify early disease to allow remineralization instead of restoration.

Cavitated lesion

Loss of outer surface layer of crown or root—requires restoration.

Noncavitated lesion

Demineralized area that can be remineralized or arrested.

Caries detection methods

Visual, tactile (light explorer use), air, radiographs, and good lighting.

Normal conditions

Explorer glides smoothly; slight bump may be felt at CEJ.

Small calculus deposits

Gritty sensation (like smooth side of a nail file).

Large calculus ledge

Explorer moves out and around bump (like rough sandpaper).

Overhanging restoration

Explorer must move away and over (like buckled sidewalk).

Deficient restoration margin

Explorer dips in (like stepping off a curb).

Carious lesion

Explorer dips into rough depression (like a pothole).

Causes of undetected calculus—General

Wrong explorer, tight grasp, poor fulcrum use, middle finger not on shank, or strokes too far apart.

Undetected deposits at midlines or line angles

Not overlapping strokes, failure to use horizontal strokes, or not rolling handle around line angle.

Undetected mesial/distal deposits

Failure to extend strokes apical to contact or to roll handle properly.

Undetected supragingival deposits

Failure to use air for visual inspection.

Undetected deposits at sulcus base

Failure to insert to JE,

poor head or clinician position,

or incorrect clock position.