Objective: To describe a technique of fabricating a positioning template with silicone materials intraorally for dental colorimeters and assess the reproducibility of this technique under in vivo condition. Methods: The template was fabricated using silicone materials. A 5 mm punch was used to create a circular opening on the labial side of the template. The elastic touch probe of the colorimeter was then placed in the opening to check if there was any space between the touch probe and the template. If so, the space was filled with light body silicone material. An in vivo study was performed to assess the reproducibility of this technique. The L*, a*, b* values of 36 anterior teeth were measured by two examiners. Intra- and inter-examiner reproducibility were assessed by calculating intra-class correlation coefficients (ICCs) and the limits of agreement. Results: The results of ICCs showed that the colorimeter with the silicone template had better intra-/inter-examiner reproducibility than without the silicone template. Furthermore, the limits of agreement of the colorimeter with template showed a narrower measuring range compared with the colorimeter without the template. Conclusion:With the use of the template, repositioning of the colorimeter or spectrophotometer for each colour measurement can be precise. This kind of template enables clinicians to evaluate colour changes of teeth and restorations consistently. This technique is convenient and timesaving, and it may be helpful when using other hand-held colorimeters or spectrophotometers for colour evaluation.
Keywords: silicone material, positioning template, colorimeter, spectrophotometer, colour measurement