Comparison of the staining ability of liquid-type and tablet-type dental plaque disclosing agents

Objectives: To compare the staining ability of liquid-and tablet-type dental plaque disclosing agents (PDAs) that contain identical dye components, using quantitative clinical indices and qualitative expert evaluations to identify differences attributable to characteristics of the formulation.Methods: Data were obtained through a clinical trial conducted between April and June 2023, involving 40 participants aged 20 years (PNU IRB/2023_22_HR).Liquid-type PDA (2Tone TM , Young Dental) and tablet-type PDA (PlaqSearch TM , Tepe) were applied to six predetermined tooth surfaces.Plaque staining ability was quantitatively assessed using the Patient Hygiene Performance (PHP) index, based on intraoral photographs.For qualitative assessment, three experts independently evaluated paired images and selected those that demonstrated superior plaque disclosure.Homogeneity tests were performed to assess inter-examiner agreement, and goodness-of-fit tests were performed to analyze differences according to tooth surface. Results:The PHP index analysis revealed a statistically significant difference in plaque staining ability between liquid-and tablet-type PDAs across all tooth surfaces (P<0.05).In particular, the liquidtype PDA had significantly superior staining on the buccal surfaces of the maxillary first molars.The response distributions among the expert evaluators were homogeneous (P>0.05).Goodness-offit testing identified a statistically significant preference for liquid-type PDA on the buccal surface of the maxillary right first molar (P<0.05).Conclusions: Liquid-type PDAs had superior plaque staining ability on the buccal surfaces of maxillary first molars, compared with tablet-type PDAs.These differences appear to be related to variations in methods of application rather than superiority of the formulation.When tablet-type PDAs are used for self-care, appropriate instruction on the application technique is necessary to ensure uniform staining on surfaces with limited tongue access.