Reproducibility of peri-implant probing using a force-controlled probe

The aim of the present study was to evaluate the reproducibility of probing depth (PD) and vertical attachment level (PAL-V) measurements at endosseou s implants. Twenty partially edentulous patients who had received 44 Friali t-2 and 30 Astra implants between 1994 and 1996 were examined. At all teeth and implants, clinical parameters (GI, PII, PD, PAL-V) were measured at 6 sites using the flexible plastic version of the universal explorer TPS prob e. At the implants and at teeth that were in similar locations compared to the implants, PD and PAL-V measurements were repeated. For each of the 20 p robes that had been used for clinical examination of the 20 patients, the p robing force was assessed using a precision balance. As a measure of intrae xaminer reproducibility, the following standard deviations of single PD and PAL-V measurements were calculated: Frialit-2: 0.71/0.74 mm; Astra: 0.72/0 .75 mm; tooth: 0.59/ 0.57 mm (PD/PAL-V). Stepwise multiple regression analy sis revealed implant/tooth position and GI to influence PD and PAL-V measur ement error (P<0.001). At anterior teeth, a lower variability was observed than at posterior teeth (P<0.001). PD and PAL-V measurement error were high er at implants than at teeth and influenced by patients. The respective mod els explained 13% and 17% of the variability of the dependent variable (PD/ PAF-V), respectively. Intraexaminer variability of PD and PAL-V measurement s at implants tended to be higher than at teeth. Multivariate analysis of v ariance revealed probe and probe holder to statistically significantly (P<0 .001) influence probing force. However, the differences in probing force be tween the various probe heads were very small. They reached a maximum of 0. 054 N between probe 3 and 14 and may be looked upon as clinically irrelevan t.