Tielemans Sarah, Bergmans Lars, Duyck Joke, Naert Ignace
Department of Prosthetic Dentistry, Catholic University of Leuven, Faculty of Medicine, School for Dentistry, Oral Pathology, and Maxillofacial Surgery, Belgium.
Quintessence Int. 2007 Feb;38(2):135-42.
To define the reproducibility and accuracy of the Prepometer device (Hager & Werken) and to correlate the measured electrical resistance with the remaining dentin thickness.
In vivo standardized cavities were made on the buccal side in the cervical region of 12 intact teeth. Measurements with the Prepometer were completed before tooth extraction. After extraction, in vitro measurements of the remaining dentin thickness were performed using a microfocus-computerized tomography scanner. These in vitro scan data were compared with the in vivo measurements, and correlation coefficients calculated. The intra- and interinvestigator variability were defined, using a paired 2-tailed Student t test. The level of significance was set at 5%.
Although both the intra- and interinvestigator variability scored well, there was no clear correlation between the Prepometer measurements and the remaining dentin thickness. Because the device determines the electrical resistance of the dentin, which is related to dentin permeability, real remaining dentin thickness cannot be measured. A reasonable safety zone (3 of 12 teeth scored false negative and 1 of 12 teeth scored false positive) in terms of remaining dentin thickness was observed.
The Prepometer, a device developed to screen dentin-surface permeability by measuring its electrical resistance, was shown to be reproducible in its use. However, electrical resistance was shown not to correlate with dentin thickness. Although the Prepometer might help to estimate the risk of pulp injury after tooth preparation, its effectiveness still remains to be proven in a randomized clinical trial.
确定Prepometer装置（Hager & Werken）的可重复性和准确性，并将测量的电阻与剩余牙本质厚度进行关联。
在12颗完整牙齿的颈部区域颊侧制作体内标准化洞形。在拔牙前用Prepometer完成测量。拔牙后，使用微焦点计算机断层扫描仪对剩余牙本质厚度进行体外测量。将这些体外扫描数据与体内测量数据进行比较，并计算相关系数。使用配对双尾Student t检验确定研究者内和研究者间的变异性。显著性水平设定为5%。
尽管研究者内和研究者间的变异性评分都很好，但Prepometer测量值与剩余牙本质厚度之间没有明显的相关性。由于该装置测定的是牙本质的电阻，而电阻与牙本质渗透性相关，因此无法测量实际的剩余牙本质厚度。在剩余牙本质厚度方面观察到一个合理的安全区（12颗牙齿中有3颗出现假阴性，12颗牙齿中有颗出现假阳性）。
Prepometer是一种通过测量电阻来筛查牙本质表面渗透性而开发的装置，其使用具有可重复性。然而，电阻与牙本质厚度无关。尽管Prepometer可能有助于估计牙体预备后牙髓损伤的风险，但其有效性仍有待在随机临床试验中得到证实。
