In PSR scoring, calculus alone yields Code 2; what drives Code 3 or 4?

• A. Calculus alone yields Code 2; deeper pockets drive Code 3 or 4 independent of calculus presence.
• B. Calculus ensures Code 4.
• C. Calculus has no effect on PSR.
• D. Calculus lowers Code to Code 0.

Answer: (A)

PSR codes reflect two features in a sextant: calculus/defective margins and the depth of the periodontal pockets. When calculus or defective margins are present but the pockets are shallow, the code stays at a 2. Codes 3 and 4 come from deeper probing depths, with pocket depths in the 3.5–5.5 mm range for the higher Code 3 and greater than 5.5 mm for Code 4. So, regardless of calculus being present, it’s the actual pocket depth that pushes the code up to 3 or 4. That’s why calculus alone yields Code 2, and deeper pockets drive the higher codes.