Intra and inter-examiner reproducibility of probing pocket depth in vivo

The three trained examiners measured PD in the 20 patients to determine the intra- and inter-examiner reproducibility. PD is defined as the measurement in millimeters from the gingival margin to the bottom of the gingival sulcus. The study used a Williams manual periodontal probe (1, 2, 3, 5, 7, 8, 9 and 10 mm), introducing the probe in the interior of the gingival sulcus and following the length of the tooth until resistance was felt by the penetrating probe. Each patient had six sites probed per tooth (mesial buccal, buccal, distal buccal, mesial lingual, lingual and distal lingual), excluding third molars. The PD measurements were done using the following criteria: all measurements were rounded to the closest 0.5 mm (up or down) and when the PD measurement was exactly between two marks on the probe (except between 3 mm and 5 mm, where the middle measurement equaled 4 mm), the closest millimeter immediately above the mark was recorded. Each patient had to have a minimum of six teeth per quadrant in order to be included in the study. The initial probe depths (baseline) were taken using the following methodology: on Day 1, Examiner 1 did an initial PD (baseline); two days later (day 3), Examiner 2 did an initial PD; and on day 5, Examiner 3 did an initial PD. On day 7 the second round of PD began on the patient by Examiner 1, with Examiners 2 and 3 probing on days 9 and 11, respectively. This same methodology was used on all 20 patients until data was recorded for all of them. Each patient was probed a maximum of six times (two probes per examiner: the initial and the repeated probing). Therefore, the 20 patients were probed twice in different appointments by the three examiners. The sequence of the examiners was random (a lottery).