The Accuracy of Tooth Color Determination by Dental Students

Method: Included in the study were 5^th year volunteering students from School of Dentistry Bucharest. They determined color (L – luminosity, C – chroma, h – hue) for 3 upper anterior teeth (left central incisor, left lateral incisor and left canine) using the shade guide system (3D-Master, Vita Zahnfabrik) and the accuracy of their determinations was checked using the spectrophotometer (Easy Shade, Vita).

Result: The study was conducted on a sample of 105 students of which 75.2% were female with an average age of 24. Conventional visual tooth shade evaluation measured statistically significant differences compared with spectrophotometric variant C and h (Wicoxon test, L: p=0,173; C: p<0,001; h: p=0,006). Regarding the visual evaluation of L, 44% of students correctly determined luminosity, and 95% of them recorded a low margin of error (± 1 unit on the Vita key). Students managed to a higher degree to correctly evaluate L for teeth with medium values of L (2 or 3) but few were able to correctly evaluate teeth with extreme values for L (1 or 4); subjects were more correct in the identification of L for upper incisors and recorded more errors in the evaluation of the canine; they chose only values from the color key, but no student identified intermediate values, despite them being determined by spectrophotometer measurements (1.5 or 2.5). Regarding C, 45% were correct in their evaluation, and 41% chose a value higher than the real one. Only 31% of students correctly identified h. A few students (10%) correctly evaluated all 3 parameters - L, C, h.

Conclusion: Tooth color determination requires training. Higher evaluation problems were observed in assessing luminosity when extreme values are encountered.