Objectives: This study was aimed at evaluating the correlation and reproducibility of gingival thickness quantification using digital and direct clinical assessment methods.
Materials and methods: Patients in need of tooth extraction were allocated into two groups according to the gingival thickness measurement method, either using an endodontic spreader (pre-extraction) or a spring caliper (post-extraction), both on the mid-facial (FGT) and mid-lingual (LGT). Pre-extraction Digital Imaging and COmmunications in Medicine (DICOM) and STereoLithography (STL) files of the arch of interest were obtained and merged for corresponding digital measurements. Inter-rater reliability between digital and direct assessment methods was analyzed using inter-class correlation coefficients (ICC).
Results: Excellent inter-rater reliability agreement was demonstrated for all parameters. Comparison between the endodontic spreader and the digital method revealed excellent agreement, with ICC of 0.79 (95% CI 0.55, 0.91) for FGT and 0.87 (95% CI 0.69, 0.94) for LGT, and mean differences of 0.08 (- 0.04 to 0.55) and 0.25 (- 0.30 to 0.81) mm for FGT and LGT, respectively. Meanwhile, the comparison between the caliper and the digital method demonstrated poor agreement, with ICC of 0.38 (95% CI - 0.06, 0.70) for FGT and 0.45 (95% CI - 0.02, 0.74) for LGT, and mean differences of 0.65 (0.14 to 1.16) and 0.64 (0.12 to 1.17) mm for FGT and LGT, respectively.
Conclusions: Digital measurement of gingival thickness is comparable with direct clinical assessments performed with transgingival horizontal probing using an endodontic spreader.
Clinical relevance: Digital assessment of gingival thickness is a non-tissue invasive, reliable, and reproducible method that could be utilized as an alternative to horizontal transgingival probing.
Keywords: 3-D imaging; Gingiva; Phenotype; Radiology.