The Chromatometry Study Of Compatibility Between Four Shade Guides And Maxillary Anterior Teeth Of Chinese People In Shandong

ObjectiveTo introduce a computer colorimeter of color measurement-ShadeEye NCC.To study the color distribution space of maxillary anterior teeth of Chinese people in Shandong and effects of sex,age,tooth position,different regions of tooth on tooth color.And also,to study the color dimensions of four shade guides and analyze the association between shade guides and natural teeth.MethodsBased on CIE₁₉₇₆L^*a^*b^* color system,a total of 1020 maxillary anterior teeth consisted of 170 Chinese people aged from 16 to 60 years in Shandong and four kinds of shade guide,including Vita Classical,Vita 3D-Master,Ivoclar Chromascop,Shofu Vintage Halo,were measured by ShadeEye NCC computer colorimeter and analyzed by ShadeEye Viewer software in three positions(cervical,middle,incisal),trying to have a basic understanding of the database. Results1.Statistical analysis showed that the color distribution space of maxillary anterior teeth of Chinese people in Shandong is wide.The 95% normal chroma value of natural teeth were ranged L^*:58.54～88.19,a^*:-0.53～4.92,b^*:7.76～28.37。The color difference(ΔE)between the upper and lower limits of 95%confidence is 37.569.2.The difference of color data between male and female was obviously related(p＜0.01),and there is significant difference.The value of male is lower than the female's,the hue is redder and more yellow,and the saturation is higher.3.The results showed that the values of L^*and a^* were negatively related to age in three positions(cervical,middle,incisal)of teeth(r＜0, p＜0.01).The lightness of natural teeth gets lower as the age increasing. The value of b^* was positively related to age just at the cervical and middle sites of teeth(r＞0,p＜0.01),while the incisal site of teeth was not related to age(p＞0.05)。4.There is no significant difference on the values of L^*,a^*,b^* between the central incisor and lateral incisor(p＞0.05),while obvious difference between canine and incisor(p＜0.01).5.Statistical analysis showed that the chroma value of four shade guides were ranged as follows,Vita Classical:L^*(60.03～71.63),a^* (-1.52～0.95),b^*(6.92～20.28);Vita 3D:L^*(60.28～78.49),a^* (-1.25～4.72),b^*(6.30～27.14);Ivoclar:L^*(60.58～79.31),a^*(-1.86～5.11),b^*(9.54～26.05);Shofu Halo:L^*(54.31～75.56),a^*(-1.63～2.01),b^*(10.13～27.15).6.Compared with maxillary anterior teeth of Chinese people in Shandong,there is significant difference on almost all chroma value except for the L^*,a^* of Vita 3D and the a^* of Ivoclar.Conclusions1.The color distribution space of maxillary anterior teeth of Chinese people in Shandong is wide.They have higher lightness and larger saturation(red and yellow).2.The color of natural teeth is effected by sex,age,tooth position and different sites,some changes have been found.3.The chromatic distribution spaces of the four shade guides are narrower than that of natural teeth.The L^*,a^* and b^* did not extend through the volume of Chinese natural tooth required.They are lack of higher lightness shade tabs.4.The L^*,a^* and b^* of Vita Classical are all illogical,it is lack of higher lightness and larger saturation(red and yellow)shade tabs.Its color dimension is far away from Chinese natural teeth.Shofu Halo shade guide is lack of lower saturation(red and blue)shade tabs.Ivoclar shade guide lacks lower saturation(blue)shade tabs.Vita 3D shade guide is most suitable with Chinese natural teeth in Shandong,except lacking higher lightness shade tabs.5.The color measurement with ShadeEye NCC computer colorimeter is a better method,it is reliable to analyze the relation between different color under the same condition.