What is a critical probing depth below which scaling and root planing may induce attachment loss?

In the context of periodontal therapy, particularly scaling and root planing (SRP), probing depth is a significant factor to consider when evaluating the potential outcomes of the procedure. A critical probing depth has been identified in clinical studies, whereby performing scaling and root planing may result in detrimental effects, such as attachment loss.

Probing depths less than 3 mm are generally considered safe and often associated with a more favorable prognosis after SRP. When the probing depth exceeds approximately 3 mm, specifically around the range of 4 mm and above, there is a higher risk of attachment loss following the procedure. Thus, a probing depth of 2.9 mm is critical in ensuring the treatment remains effective without jeopardizing the periodontal attachment.

In summary, the threshold of 2.9 mm signifies that probing depths below this level are less likely to result in attachment loss, making it important for clinicians to assess periodontal pockets accurately to guide treatment decisions effectively. The other options suggest depths that could lead to complications following scaling and root planing, reinforcing the importance of the identified critical depth.