GCF sclerostin levels were significantly higher in Group 3 (patients with severe AP and higher AS-PAI scores) as compared to Groups 1 and 2 (75.8 ± 43.3 vs. 37.0 ± 6.4 and 42.7 ± 8.2 ng/mL; p < 0.001, respectively, for Groups 3, 2, and 1), but did not vary significantly between Groups 1 and 2 (p > 0.05). The gene discussed is SOST; the disease is alkaline phosphatase measurement.