Comparison of Qualitative and Quantitative Methods for Gingival Thickness Assessment: Color-Coded Probe Versus Ultrasound Measurements

Accurate assessment of gingival thickness is essential for clinical decision-making in implant dentistry, periodontology, and orthodontics. Qualitative phenotype assessment using color-coded periodontal probes is commonly applied as a rapid screening tool, whereas ultrasonography provides quantitative, non-invasive measurements expressed in millimeters. The relationship between these two approaches, however, remains insufficiently defined. The aim of this study was to evaluate the correspondence between qualitative gingival phenotype classification using a color-coded probe and quantitative soft tissue thickness measured with an ultrasound-based system. In this observational diagnostic substudy, the gingival phenotype was categorized as thin, medium, thick, or very thick based on probe translucency and compared with ultrasound-derived thickness values obtained at standardized sites. Qualitative phenotype categories showed a consistent association with quantitative measurements, supporting the role of color-coded probes as screening tools within a complementary diagnostic framework. Ultrasonography provided objective data suitable for detailed assessment and monitoring. These findings support a complementary diagnostic approach combining qualitative screening with quantitative measurement.