COMPARISON OF PERIODONTAL AND PERI-IMPLANT PROBING BY DEPTH-FORCE PATTERN-ANALYSIS

The purpose of this study was to compare the tissue resistance to prob ing and the accuracy of depth determination at different force levels around implants and teeth. In 11 subjects 1 implant and 1 tooth at a c omparable location and with comparable probing depth were investigated . The sites were located on either the mesial or distal aspect of the tooth and the implant. A probing device was used which allowed simulta neous monitoring of probing force and probe penetration and which stan dardized the insertion pathway for repeated measurements. The probing instrument was fitted with an attachment for an aiming device to take a radiograph with the probe tip in the sulcus, using a standardized pr ojection geometry. Probing depth values were determined at 0.25, 0.50, 0.75, 1.00 and 1.25 N probing force. The standard error of the indivi dual measurement (S-i), evaluated by comparison of repeated measuremen ts in the same session, was 0.2 mm on implants and 0.1 mm on teeth. Fo r implants there was a trend for slightly better reproducibility at hi gher force levels. Curve analysis of depth force patterns showed that a change in probing force had more impact on the depth reading in the peri-implant than in the periodontal situation. The mean distance betw een the probe tip and the periimplant bone crest amounted to 0.75+/-0. 60 mm at 0.25 N probing force. It is concluded that peri-implant probi ng depth measurements are more sensitive to force variation than perio dontal pocket probing.