In Vitro Model Study On A New Shade-matching Device For Aesthetic Dental Color Selection

ObjectiveTo evaluate the reliability and accuracy of spectrophotometer and the effectiveness of gingival in visual shade-match in vitro model.MethodsThe spectrophotometer was used to measure the color parameters (CIE1976 L*a*b*) of incisal, body, cervical area of two shade guides(VITA 3D-Master, Shofu Vintage NCC) repeatedly for the reliability assessment and the accuracy assessment, and also the color parameters (CIE1976 L*a*b*) of incisal, body, cervical area of 42 tabs of Shofu Vintage NCC shade guide fixed in 4 kinds of gingival-indicator for the gingival shade guide effectiveness assessment inside a black box.ResultsReliability of spectrophotometer was as follows:VITA 3D-Master: incisal(96.9%±1.8%), body(89.2±3.4%), cervical(89.2%±3.2%); Shofu Vintage NCC: incisal(75.2%±3.0%), body(82.9%±2.9%), cervical (83.3%±3.0%).There was no significant difference among three areas(p>0.05). The concordance rate of VITA 3D-Master was higher compared to Shofu Vintage NCC(p<0.05).Accuracy of spectrophotometer was as follows:VITA 3D-Master:incisal (76.2%±7.2%), body (86.9%±4.7%), cervical (74.6%±6.8%); Shofu Vintage NCC: incisal(48.1%±5.2%), body(74.3%±4.8%), cervical(57.6%±5.9%). The concordance rate of body area was higher compared to other areas(p<0.05). The concordance rate of VITA 3D-Master was higher compared to Shofu Vintage NCC(p<0.05).△E value of VITA 3D-Master:incisal (1.88±0.09) NBS, body (1.12±0.10) NBS, cervical (1.48±0.10) NBS;△E value of Shofu Vintage NCC:incisal (1.83±0.14) NBS, body (1.16±0.07) NBS, cervical (1.67±0.08) NBS. The△E of body area was lower compared to other areas(p<0.05). There was no significant difference between two kinds of Shade guide (p>0.05).The effectiveness of gingival shade guide (△E value) was as follows:incisal (0.61±0.29) NBS, body (0.51±0.27) NBS, cervical (2.93±0.79) NBS. The△E of cervical area was higher compared to other areas(p<0.05). There was no significant difference among Gumy,2,3,4 groups (p>0.05).ConclusionsThis in vitro study showed a varying degree of reliability and accuracy for Spectrophotometer depending on the type of shade guide system used and the region of shade, Spectrophotometer showed good repeatability and accuracy, could be used in clinic; The gingival color has an effect on the cervical of tabs, while has little effect on the incisal and body, and there are no significant differences statistically in comparison among different color; Suggest using one color gingival shade when taking visual shade match.