What is the typical orientation of the horizontal stroke in relation to the tooth surface?

The typical orientation of the horizontal stroke used in periodontal instrumentation is oriented circumferentially around the tooth rather than strictly following an apical/coronal direction. The purpose of this technique is to effectively remove plaque and calculus from the tooth surface while minimizing trauma to the periodontal tissue.

While the apical orientation may be employed in some specific situations, the most effective approach is often a gentle horizontal motion, which can help to dislodge debris effectively. The other orientations, such as perpendicular to the tooth surface or at a 45° angle, may be employed depending on the area being treated or the type of instrument being used; however, they do not typically describe the standard horizontal stroke technique.

Thus, the orientation of the horizontal stroke, while flexible depending on the clinical situation, primarily aligns with an effective circumferential movement instead of a strictly apical or coronal approach. This technique enhances the cleanliness of the tooth while protecting the surrounding tissue from damage.