공명진동 분석과 Periotest에 의한 골결손 임플란트의 안정성 측정

Abstract

Implant stability is an indirect evidence of osseointegration and strong osseointegration is a requirement for long-term success of implant. There are a lot of measurements for implant stability such as percussion, radiographs, insertion & removal torque and cutting resistance. Among many measurements, non-invasive Periotest and Osstell are mainly used in clinics. Osstell is a quantitative device that measures implant stability by RFA. However, it has disadvantages such as necessity of special transducer fixed in implant and limitation of use for cement-retained implant. Periotest used to measure implant stability for a long time, is easily available without replacing attachment. But it has disadvantages like errors occurring while measuring a number of variables and a lack of reproducibility. Many studies have found a significant relation between measurement values of implant stability obtained by the two different devices. In this study, we analyze changes of measurement values of Osstell Menotr and Periotest followed by vertical bone loss and correlation between the two devices. And then we try to use the results for evaluation of implant stability. Acrylic resin block models implanted with external hex type implants were manufactured (16blocks). Models were divided into four groups : buccal , mesio-buccal , mesio-bucco-distal , circular bone loss. The amount of bone loss was increased gradually from 1mm to 10mm by trephine bur. And then implant stability was measured for each step by Osstell Mentor and Periotest(ISQ value & PTV) Although PTV and ISQ values at all types of bone loss decreased gradually by amount of bone reduction, both PTV and ISQ value showed certain difference as the type of bone reductions closer to circular bone loss than partial vertical bone loss. In case of circular bone loss, the evaluation of implant stability using Periotest and Osstell Mentor can be clinically useful. However, at partial vertical bone loss, the clinical usefulness decreases since no proportional value to destruction degree is shown. It was thought that the partial osseointegration which remains at vertical bone destruction limits micro-mobility. Therefore, when partial bone loss is clinically progressive, additional assessment method is considered to be needed, because Periotest and Osstell Mentor have some limits in obtaining accurate data about implant stability.