[The reliability of the salivary occult blood to test gingival inflammation]

To evaluate the reliability of salivary occult blood test(SOBT) for gingival inflammation.

Forty-five pre- and post-stimulation saliva samples were tested for occult blood, with bleeding on probing (BOP) as an indicator of gingival inflammation. Subjects with BOP%<15% were defined as control group. The examinations were repeated 3 months after periodontal initial therapy. The relationship between the results of SOBT and gingival inflammation was analyzed. SAS6.12 software package was used for statistical analysis.

The SOBT of pre-stimulation was higher in gingivitis group than in control group (P<0.05). BOP% and SOBT of post-therapy was significantly decreased (P<0.01), with 90% of pre- and 63% of post-stimulation SOBT turning negative. The sensitivity and specificity of pre- stimulation SOBT in screening gingivitis were 32.35% and 100%. The sensitivity and specificity of the post-stimulation SOBT were 88.24% and 81.82%.

SOBT is correlated with gingival inflammation, which may be used as an objective parameter to evaluate gingival inflammation and the efficacy of periodontal therapy at individual level. It may offer a simple screening method for gingival inflammation applied in periodontal epidemiologic studies in large population.