The Role of Explorers and Probes
Explorers and periodontal probes are fundamental diagnostic instruments. The explorer detects surface irregularities such as caries, calculus, and defective restorations, while the periodontal probe measures pocket depths and attachment levels. Mastery of these instruments is essential for accurate diagnosis.
Explorer Technique for Caries Detection
Instrument Selection
- No. 23 Shepherd Hook: General-purpose explorer for detecting occlusal and interproximal caries
- ODU 11/12: Double-ended explorer ideal for subgingival calculus detection and root surface evaluation
- No. 6 Pigtail: Useful for interproximal areas and around margins of restorations
Technique Fundamentals
- Use a modified pen grasp with a light touch — excessive pressure can damage demineralized enamel
- Establish a finger rest (fulcrum) on an adjacent tooth for stability
- Move the explorer with short, controlled strokes across the tooth surface
- A carious lesion will feel like a "catch" or "tug-back" — a sticky, soft resistance
- Current evidence suggests visual-tactile examination combined with radiographs is more reliable than explorer probing alone for early caries
Periodontal Probing
Probe Types
- Williams probe: Markings at 1, 2, 3, 5, 7, 8, 9, 10 mm — most widely used
- UNC-15 (University of North Carolina): Markings every millimeter up to 15 mm
- Marquis probe: Color-coded bands at 3, 6, 9, 12 mm for quick visual reference
Probing Technique
- Insert the probe parallel to the long axis of the tooth
- Use no more than 20–25 grams of pressure (about the weight of a small coin)
- Walk the probe around the entire circumference of each tooth, recording six measurements per tooth: mesiobuccal, mid-buccal, distobuccal, mesiolingual, mid-lingual, distolingual
- Note bleeding on probing (BOP) — a key indicator of active inflammation
- Record recession measurements separately (distance from CEJ to gingival margin)
Charting Best Practices
- Use a consistent charting system (manual or digital) across the entire practice
- Record all six probing depths per tooth at every periodontal evaluation
- Note BOP, suppuration, furcation involvement, and mobility
- Compare measurements to previous exams to identify trends
- Calibrate probing technique among all hygienists in the practice to ensure consistency
Tips for Accuracy
- Replace probes that are bent, worn, or have illegible markings
- Account for inflammation — swollen tissue may produce artificially deep readings
- Be mindful of calculus that can deflect the probe and produce false-shallow readings
- Always cross-reference clinical findings with radiographic evidence