EFFECT OF GINGIVAL WALL ON RESISTANCE TO PROBING FORCES

This study was conducted to determine whether the gingival tissue late ral to the periodontal sulcus contributes resistance to the advancemen t of a periodontal probe tip into the sulcus under different applied p ressures. An electromechanical device was used to advance a probe tip 0.6 mm in diameter into the facial sulcus at a constant speed until re sisting forces of 0.70 N were encountered. The device registered the r esisting force and probe advancement simultaneously. The gingiva of al l 2nd incisors, 2nd premolars, and 1st molars of 4 young adult male be agle dogs were tested. After the first measurement, the buccal gingiva of experimental sites were incised mesiodistally from the gingival ma rgin to the alveolar crest and the sulcus was reprobed. 2 experimental and control quadrants were selected randomly resulting in 6 sets of b oth experimental and control data from each animal. The data were anal yzed with analysis of variance. The analysis demonstrated significant variation from site to site, and dog to dog; therefore, only changes b etween the 1st and 2nd probings at the same sites could be compared. L ess variability of probing distance in different animals occurred at h igher forces; however, the incision had a significant effect on probin g distance at these forces. The pressure at which probing distance had less variability among animals and least affected when the gingival s ulcular wall was incised was estimated to be 106 N/cm(2). This corresp onds to 30 g force on the 0.6 mm diameter probe.