RESUMEN
BACKGROUND: The authors have previously reported development of a novel immunochromatographic device (DK13-PG-001) for specific detection of Porphyromonas gingivalis (Pg). In this study, clinical usefulness of the detection device during periodontal therapy is presented. METHODS: The multicenter study was conducted with 62 patients contributing 118 periodontitis sites with probing depth (PD) of 4 to 9 mm. Subgingival plaque samples were used for detection of Pg by DK13-PG-001 and the PCR-invader method at: 1) baseline (BL); 2) reevaluation (RE; after scaling and root planing); and 3) final evaluation (FE; after local drug delivery system). Periodontal examinations were performed concurrently with the test for Pg detection. Plasma immunoglobulin G (IgG) titers against Pg were also determined in patients using an enzyme-linked immunosorbent assay. RESULTS: DK13-PG-001 score and number of Pg by the PCR-invader method showed a strong correlation (r = 0.862) at three stages during periodontal therapy (n = 354). High sensitivity and specificity of DK13-PG-001, in comparison with the PCR-invader method, were shown. A significant correlation was found among device score, number of Pg by the PCR-invader method, and PD and clinical attachment level at BL and RE. Plasma IgG titers against Pg were significantly reduced at FE in comparison with BL. Weak but significant correlations between IgG titers and device scores were shown at BL and FE. CONCLUSION: Results suggest the DK13-PG-001 device is a useful tool for detection of Pg in dental offices and can aid clinical evaluation of the extent of periodontitis and therapeutic efficacy.