[Gingival crevicular fluid enzyme levels at different destruction sites in the same teeth]

To direct selecting proper sampling methods and sites in clinical research.

Gingival crevicular fluid (GCF) was sampled separately at the mesial-buccal and distal-buccal sites in the same teeth, which were destroyed differently. Clinical parameters were recorded in the subject sites and its adjacent sites. Aspartate Aminotransferase (AST) and Alkaline Phosphatase (ALP) in the GCF were determined. Difference of the enzyme levels between the two sampling sites, and relations between the enzyme level and all the clinical parameters were assessed.

GCF-AST, ALP per sample at severely diseased sites were much higher than that from healthy and/or mild sites in the same teeth. Significant positive correlation (P < 0.001, r > 0.5) was demonstrated between enzyme levels in the sampling sites and probing depth (PD) and attachment level (AL) of the lingual sites. However, there was mild significant correlation (P < 0.05, r = 0.275) between ALP level in the sampling sites and PD of the proximal-buccal sites of its adjacent teeth. No significant correlation (P > 0.05) was found between AST level in the sampling sites and PD, AL of the adjacent teeth sites, and also between ALP level in the sampling sites and AL of the adjacent teeth sites.

Site-specificity of periodontal disease was further demonstrated. GCF components were influenced reciprocally more obviously in the same proximal than by other sites.