Histological determination of probe tip penetration into gingival sulcus of humans using an electronic pressure-sensitive probe.

The purpose of this investigation was to determine histologically the depth of probe tip penetration into the clinically healthy gingival sulcus of humans using a controlled inserton pressure of 25 g. The midfacial gingival units of 22 maxillary and mandibular incisor, canine and premolar teeth, displaying no visual signs of inflammation, were used for probing determinations. An electronic pressure-sensitive probe, with a terminal probe tip diameter of 0.35 mm, was used to standardize insertion pressures. After insertion of the probe into the sulcus, it was then aligned on the facial surface of the gingiva with the tip corresponding to the depth and location of probe insertion. A horizontal reference incision was made on the facial gingival surface which corresponded to the depth of the sulcus probed. This incision served as a histologic landmark of probe tip generation. Gingival biopsies were taken, and step-serial sections analyzed histologically and histometrically. Probe tip penetration was coronal to the apical end of the junctional epithelium in all cases (mean = 0.25 mm). In addition, probe tip penetration was always apical to the coronal end of the junctional epithelium (mean = 0.70 mm).