樹脂モデルにおける動揺度計測装置と共振周波数分析装置の検討： 計測条件が計測値に与える影響

抄録

Periotest measures the mobility of an implant by using percussion, and Osstell measures the stability of an implant by applying resonance frequency analysis. Both of the measurement values are useful references to understand the implant condition of osseointegration. In some cases, it is decided to adopt an immediate load based on absolute values of measurements. However, there are few reports concerning effective factors on the measurement values. A resin model that can easily reproduce the same conditions of osseointegration was made. The influence was evaluated under various conditions of length of transducer (Osstell only), changing angle between the detector and distance of resin model,and changing the length of the implant fixture.
The following conclusions were obtained.
1. In the case of Periotest, the percussion direction and the length of fixture did not affect the measured values, and the measured values were stable.
2. In the case of Osstell, the length of transducer had the greatest effect on the value of ISQ. The ISQ values of F1L5.0 were higher than those of F1L8.5 (average difference was 4.0～13.9). The ISQ values of F1L8.5 decreased with angle between transducer and resin model (parallel, oblique angle and right angle), but those of F1L5.0 increased slightly. The length of implant fixture did not affect the ISQ values.
3. On the waveform of F1L5.0, a sub peak was observed on the left of the maximum peak wave more often while F1L8.5 showed almost typical Implant Stability Quotient (ISQ) waveforms.
4. Periotest values measured based on the center axis of the implant were better than Osstell values (ISQ) because Periotest values hardly depended on the direction and the measured values were stable.
5. It is possible to calculate the reproducible measurement value when the measurement conditions of Periotest and Osstell were controlled. However, an overall judgment based not only on a physical evaluation is necessary.