Comparative study on dental plaque disclosing products

Objectives: The purpose of this study was to analyze the dental plaque disclosing products which can differentiate the plaque condition by several colors. Methods: We evaluated 3 commercial products: GC Tri Plaque ID Gel (TPID, GC), 2tone Disclosing Solution (2tone sol., Young Dental) and HurriView II (Hur. II, Beutlich LP, Pharmaceuticals). To analyze color change with pH, the absorbance of red and blue color was measured using dilution of products with 0.1M lactic acid buffer at pH4.5 and pH7.0. The absorbance change was statistically analyzed (ANOVA, Turkey′s). To compare the staining ability, Streptococcus strain was anaerobically grown on sterile plates for 24 hours. The pH on the biofilm was measured. The stained biofilm was observed with digital microscope (VHX-100, KEYENCE). Results: Absorbance of red color for only TPID was decreased at pH4.5 compared to absorbance at pH7.0. TPID indicated significantly higher decline rate (40%, p<0.01). And the color of TPID changed to light blue by red color discoloration on pH4.5. Furthermore all products showed no difference in absorbance of blue color at pH4.5 and pH7.0. In the biofilm assay, all products stained biofilm. Only TPID changed to light blue under low pH on the biofilm. Conclusion: Absorbance of red color of TPID at pH4.5 reduced and absorbance of blue color did not change. In vitro biofilm was stained light blue under low pH by only TPID. This study suggested TPID may be more useful product to find low pH region on dental plaque than other two products.