Table 4: Correlation between OHI-S score with Russell’s Index and Gingival Bleeding Index.

Group Correlation between OHI-S score verses Russell’s Index Gingival Bleeding Index Control Correlation coefficient 0.721 0.371 P value <0.001 <0.001 N 250 250 Substance abusers Correlation Coefficient 0.479 −0.200 P value <0.001 0.001 N 250 250