The Study By Restoration Color Matching With Four Methods

Objective:Comparing the color difference valuesâ–³E between natural teeth and PFM (porcelain-fused-to-metal restoration) producted by four different shade matchings, to evaluate the reliability and reasonability of tooth color matching by different methods.Methods:The experimental objects are 14 patients of one maxillary incisor dental defect, needing Ni-Cr ceramic restorations in Dalian Stomatology Hospital and every patient s incisor dental defect is less than two teeth. The same name tooth is existing, live and healthy. And there are no carious lesion and restoration in it. The color is uniform and normal. The surface have no dental calculus and plaque. The color of gingival is healthy and have no periodontopathy. Dentition is regular arrangement and no history of orthodontic or bleach treatment. The experimental teeth are ultrasonic scaled before color selection in order to remove soft dirt. All patients with lipstick removed and a grey bib covering the personal clothing are performed at the same period of time (10:00-14:00 hours) on clear days, under window daylight. (1) Clinician visual shade matching:The shade matching is performed by three clinicians with negative history of visual color deficiency and rich chromatics knowledge. Making shade matching with Vita 3D-Master shade guide in the follow orders:value, chroma, hue. (2) Technician participation color selection:The technician who will make the metal ceramic restorations is invited to participate color selection with the clinician as aforesaid methods.(3) Computer colorimeter color selection: The experiment use Vita Easyshade to determine the value of L*,a*, b* of the middle 1/3 of the tooth. Every tooth determines three times and the average values are the final results.(4) Digital camera color selection:The digital photographes of Vita 3D-Master shade guide and patients teeth are transmitted to the computer of technician by internet and used as the reference of restorations producted. The same technician product restorations with the four methods for every patient after tooth preparation as regular process. The satisfaction degree of patients are investigated by double-blind method when trying them in. Then the value of L*, a*, b* of the middle 1/3 of the restorations are determined by Vita EasyShade.The values of AE are calculated by equation and compared in One-Way ANOVA using SPSS 11.5 software.Results:The average color difference valuesâ–³E between natural teeth and PFM producted by four different shade matchings:Clinician visual shade matching 5.68, Technician group 4.59, Digital camera group 3.39, Computer colorimeter group 5.96. The difference between Digital camera group and Technician group,Technician group and Clinician visual shade matching both have statistics significance(P<0.05). Clinician visual shade matching and Computer colorimeter group has no statistics significance (P>0.05).The satisfaction rate of patients:Digital camera group 85.71%, Technician group 71.43%.Clinician visual shade matching 64.29%, Com-puter colorimeter group 57.14%.Conclusion:Digital camera group is the best in shade selection. Technician group is better than clinician visual shade matching.The clini-cian visual shade matching and computer colorimeter group have no obvious difference.