Diagnostic accuracy of transmucosal probe visualization for peri‐implant mucosal phenotype assessment: A cross‐sectional study

BACKGROUND: This study evaluated the diagnostic accuracy of visual assessment of mucosal transparency using a standard periodontal probe (VAT) to differentiate between thin and thick peri-implant mucosal phenotypes, compared to horizontal transmucosal probing (HTP). A secondary objective was to assess facial mucosal thickness (FMT) threshold values for peri-implant mucosa phenotype classification. METHODS: Adult subjects with at least one non-molar single implant-supported prosthesis (ISP) were screened. To evaluate VAT, a standard periodontal probe was inserted through the peri-implant sulcus on the midfacial aspect. FMT was measured via HTP using an endodontic spreader. RESULTS: A total of 247 subjects and 281 ISPs constituted the study population. Setting a 2 mm threshold, 66.2% of sites were classified as thick and 33.8% as thin. Compared to HTP, VAT demonstrated a sensitivity (SE) of 12.6%, a specificity (SP) of 96.2%, a positive predictive value (PPV) of 63%, and a negative predictive value (NPV) of 66%. At the 1.5 mm threshold, 86.1% of sites were thick and 13.9% thin, with 25.6% SE, 96.3% SP, 53% PPV, and 89% NPV. At the 1 mm threshold, 92.2% of sites were thick and 7.8% thin, with 41% SE, 96% SP, 47% PPV, and 95% NPV. Receiver operating characteristic analysis revealed the best-fitting balance for PPV (58%) and NPV (91%) at an FMT of 1.25 mm. CONCLUSIONS: Regardless of the FMT threshold applied, VAT demonstrated limited diagnostic accuracy, in particular for thin phenotypes, proving unreliable for the dichotomic characterization of thin and thick peri-implant mucosal phenotypes. This study was approved by the ethical committee for clinical studies in the canton of Bern, Switzerland (KEK-BE-No. 2023-01962).