Clinical and Radiographic Gingival Thickness Assessment at Mandibular Incisors: an Ex Vivo Study

Purpose: Gingival phenotype influences the outcomes of various dental procedures. The objective of the current study was to assess the agreement between various clinical and radiographic methods for evaluating gingival thickness. Materials and Methods: This ex-vivo study evaluated gingival thickness on 20 porcine cadavers. Gingival thickness was assessed at both central mandibular incisors with: a) trans-gingival probing with a standard periodontal probe (PB); b) trans-gingival probing with a stainless steel acupuncture needle (AN); c) ultrasound device (USD); and d) Cone Beam Computed Tomography (CBCT). Intra-examiner reproducibility and method error were also evaluated. Results: Trans-gingival measurements with the standard PB and the AN were found to be almost identical in gingival thickness assessment (mean GT 1.11 mm vs 1.14 mm for the left incisor and mean GT 1.12 mm vs 1.11 mm for the right incisor, respectively). USD and CBCT yielded values that were statistically significantly higher than AN. Both USD and CBCT values were higher than PB, but this difference was statistically significant only for the left central incisor. Finally, USD values exceeded CBCT measurements, but this difference was not statistically significant. There was no evidence of systematic differences between the repeated CBCT measurements (p = 0.06 for the left incisor and p = 0.55 for the right incisor). Conclusions: CBCT measurements proved to be highly repeatable and comparable to the USD measurements, while there were some indications that both CBCT and USD measurements were systematically higher than either PB or AN. Keywords: cone-beam computed tomography, gingival biotype, periodontal tissue, ultrasound