Randomized multi-centre study on the effect of training on tooth shade matching.

OBJECTIVES The aim of this study was to find out whether Toothguide Trainer, TT, and Toothguide Training Box, TTB, show any training effects, independent of the shade guide chosen. METHODS Students from four dental schools (N=78) were included in this study. The participants were randomized into a study, 42 students (age range: 19-27 years; 69% female, 31% male) and a control group of 36 students (age range: 19-30 years; 57% female, 43% male). The study group started with a double blind introduction test, followed by the TT and TTB training, finishing with the final test. The control group only passed the introduction and - after a break - the final test. Eight randomly chosen samples, seven of the Vita classical and one of the 3D-Master colour scale, were marked by barcodes. Colour matching was arranged by the Vita classical scale. RESULTS The results of the pre- and final tests of both groups were combined. For every sample, the value ΔE was determined. The summation of all eight samples from the introduction and final tests offered a summarized ΔE value. The differences between introduction and final tests revealed the individual learning success. 47.6% of the study group showed statistically significant better results than the control group, 33% (p=0.031). CONCLUSION TT and TTB show a positive effect of training on tooth shade matching independent of the colour scale used. CLINICAL SIGNIFICANCE Visual shade taking is the most frequent clinical method for shade determination. To increase better results in visual colour matching, TT and TTB training is used. This is the first study examining the training effect of TT and TTB using Vita classical scale.