OBJECTIVES To evaluate the reliability and accuracy of spectrophotometric shade determination of premolars and to compare the results with those for incisors. MATERIAL AND METHODS Fifty-seven participants with natural maxillary incisors and premolars were recruited to investigate the research question. The colour of test teeth (incisors, n = 210; premolars, n = 192) was measured by use of the Vita Easyshade Advance (ES-A) and Vita Easyshade V (ES-V). Accuracy was evaluated by rating the shade tab matches recommended by the devices (scale, 1 = excellent match to 3 = mismatch). Inter-device reliability between the ES-A and ES-V for measurement of incisors and premolars was evaluated using intra-class correlation coefficients (ICC). The ratings for the accuracy of the devices were analysed using descriptive and bivariate statistics. A linear regression model was used to evaluate possible independent influencing confounders on the shade match. RESULTS Inter-device agreement of the ES-A and ES-V for measurement of incisors and premolars was excellent for all colour components (ICC > 0.9). The accuracy of both devices was acceptable to excellent for incisors and premolars, although the ES-V was more accurate than the ES-A (p < 0.001). No significant difference in accuracy was detected between premolars and incisors (p = 0.182). The linear regression model confirmed the bivariate testing. CONCLUSIONS The reliability and accuracy of spectrophotometric shade determination seem comparable for incisors and premolars. The recently introduced ES-V seems more accurate than its predecessor model. Further studies are needed to validate the results of this study.

中文翻译：

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用分光光度法测定前磨牙的阴影有多可靠和准确？

目的评估分光光度法测定前磨牙的可靠性和准确性，并将其结果与门牙进行比较。材料和方法招募了57名自然上颌切牙和前磨牙的参与者来研究研究问题。使用Vita Easyshade Advance（ES-A）和Vita Easyshade V（ES-V）测量测试牙齿的颜色（门牙，n = 210；前磨牙，n = 192）。通过评估设备推荐的阴影选项卡匹配来评估准确性（比例，1 =出色匹配，3 =不匹配）。使用组内相关系数（ICC）评估了ES-A和ES-V之间用于测量门牙和前磨牙的设备间可靠性。使用描述性统计数据和双变量统计数据分析了设备的准确性等级。线性回归模型用于评估阴影匹配中可能的独立影响因素。结果ES-A和ES-V在门牙和前磨牙测量中的装置间一致性对于所有颜色分量均非常好（ICC> 0.9）。尽管ES-V比ES-A更精确（p <0.001），但两种器械的精确度对于门齿和前磨牙都可以接受，甚至非常出色。在前磨牙和切牙之间没有发现准确性的显着差异（p = 0.182）。线性回归模型证实了双变量检验。结论分光光度色度测定的可靠性和准确性似乎可与门牙和前磨牙相媲美。最近推出的ES-V似乎比其先前的模型更准确。需要进一步的研究以验证这项研究的结果。