Objective To evaluate the effectiveness on the application of mechanical toothguide training box（TTB） to chromatics teaching of prosthodontics. Methods 12 preclinical undergraduate students were chosen to participate in the VITA 3D-Master shade-matching system simulant toothguide training process using Linearguide Training Box program of TTB. Toothguide Trainer program considered as a test was performed on the trained undergraduate students group, the postgraduate students group as well as the clinical prosthodontists group with under 5-year clinical experience. The test scores, elapsed time and the coincidence of chromatics single factor matching were recorded each time, the shade-matching efficiency was calculated. The data was analyzed with SPSS 13.0 software. Results The shadematching efficiency of undergraduate students trained by TTB（64.03±18.82） was significantly higher than before（P＜0.05）, higher than the postgraduate students group and the clinical prosthodontists group（P＜0.05）. The coincidence of chromatics single factor matching of trained undergraduate students were 64.64%（lightness）, 88.57%（chroma）, 87.70% （hue）. Conclusion TTB is a effective tool for shade-mathing practice in chromatics teaching of prosthodontics. The trained undergraduate students are less sensitive in lightness-matching.
