Experimental study of the damping behaviour of IMZ implants.

Measurements of the damping behaviour of dental implants with the Periotest device are considered to be an objective means to assess the mobility of implants. The effects of the position of an implant in the maxilla or mandible, the period of time passing between the measurements and implant placement and the height at which the Periotest measurements are performed on the damping behaviour of implants have been discussed controversially. This experimental study examined the influence of the use of different measuring devices, the measuring height and the embedding depth on the damping behaviour of IMZ implants. The implants were embedded in resin at different depths and damping measurements were carried out at different measuring heights. It was found that the values rose with an increasing measuring height and a decreasing embedding depth. Analysis of variance was used to assess the influence of the embedding depth and revealed that the embedding depth had a significant impact on the measuring values at each measuring height, above 6 mm. Moreover, it was found that the higher the measuring height, the higher the measured values and the greater the differences between the values obtained at the individual depths. The different measuring devices had no influence on the measuring results (P = 0.79). The results of this study suggest that a longitudinal follow-up of the peri-implant residual bone height around individual implants is possible. Single measuring values by themselves do not allow any conclusions about the prognosis of an implant. The assessment of the peri-implant bone height through Periotest measurements is conceivable only when a table of damping values taking into account the physical length of the implant, the embedding depth and the measuring height for the examined implant system is available. In cylindrical implants, the head of the available prefabricated measuring post can be recommended as a constant measuring point for further studies, especially when the results are to be compared with those obtained by other study groups.