Effects of image and education on the precision of the measurement method for evaluating prosthesis misfit.

STATEMENT OF PROBLEM

Various methods for measuring prosthesis misfit have been suggested. Although the cross-sectional images between the crown and abutment are used to evaluate the misfit, the effects of the image and the observer's knowledge on the precision of measurement are unknown.

PURPOSE

The purpose of this in vitro study was to investigate the effects of the image and of education on the precision of prosthesis misfit measurement methods using inter- and intraobserver variability analyses.

MATERIAL AND METHODS

The cross-sectional images in the margin were obtained using the computer-aided replica technique (CART), silicone replica technique (RT), and sectioning technique (ST). Twenty-five observers measured the absolute marginal discrepancy values in the images obtained from each group 4 times at an interval of 2 weeks; the observers went through different education sessions regarding the selection of the measurement points. The precision of measurement was determined and compared using the likelihood-ratio test statistic (α=.05) and the intraclass correlation coefficient with the linear mixed-effects model.

RESULTS

The CART group exhibited the smallest deviations in the measurement variations, followed by the ST and RT groups (P<.001). Additional education on misfit measurements generally decreased the deviation values in all the groups, but without any significant differences.

CONCLUSIONS

The cross-sectional image obtained from the measurement methods and education on the evaluation method affected the precision of the prosthesis misfit measurement. Digital methods might be a useful tool to significantly enhance the precision of the measurements.