What is a possible reason for a 1-2 mm reduction in probing depth after performing SRP?

A 1-2 mm reduction in probing depth after scaling and root planing (SRP) can primarily be attributed to the formation of a long junctional epithelium. This physiological response occurs as the tissue heals after the removal of calculus and plaque that contributes to periodontal disease.

When SRP is performed, it eliminates irritants from the root surface and reduces inflammation in the surrounding gingival tissue. As the healing process takes place, a long junctional epithelium can develop, which effectively helps to re-establish the connection between the epithelium and the tooth’s root surface. This newly formed epithelium typically results in a shallower probing depth because it adheres tighter to the root structure, thereby reducing the space measured during probing.

While improved oral hygiene can contribute to better periodontal health over time, it may not directly indicate an immediate reduction in probing depths in the short term like the formation of a long junctional epithelium can. Gingival hyperplasia typically increases the volume of soft tissue, which could paradoxically increase probing depths instead of decreasing them. Excessive plaque accumulation, on the other hand, would lead to worsening periodontal conditions, not an improvement reflected in reduced probing depths after SRP