Vita easy shade compact

The color of each upper central incisor was assessed by comparison with shade tabs of two commercially available dental shade guides (Vita classical Guide and Vita Bleached guide, Vita Zahnfabrik) and objectively with spectrophotometer (Vita Easy Shade® Compact, Vita Zahnfabrik) that was previously calibrated according to the manufacturer instructions. To standardize this evaluation, a silicone matrix was made (Zetaplus, Zhermack, Rovigo, Italy) with a 6 mm-diameter window on the buccal surface that allowed the positioning of the tip of the spectrophotometer on the middle third of the labial surface of the teeth.

At the end of the first session, tooth color was measured subjectively (Color scales) and objectively with a spectrophotometer (Vita Easy Shade® Compact, Vita Zahnfabrik) [21 (link)]. The measurements were repeated after a week, a month, 6 months and a year after whitening.

Thirty-five patients were recruited from the Faculty of Dentistry of the University of Chile. These patients had asked for a whitening treatment and volunteered to participate in the study by signing an informed consent form approved by the Ethics Committee of the Faculty of Dentistry.
All of these patients met the following inclusion criteria:

Age 18 or older (both sexes).

At least six upper healthy frontal teeth, with no restorations or crowns.

A color A3 or darker (using the Vita classical scale) as determined using a spectrophotometer (Vita Easy Shade® Compact, Vita Zahnfabrik) in the middle third on the buccal surface of central incisors.

The following exclusion criteria were used:

Pregnancy or lactation.

Bruxism or tooth sensitivity.

Teeth with prior whitening treatment (either at home or in-office).

Teeth with visible dental cracks, developmental defects, or tetracycline or fluorosis discoloration.

Presence of non-carious cervical lesions

Nonvital discolored teeth.

A digital spectrophotometer (Vita Easyshade Compact, Vita Zahnfabrik, Bad Säckingen, Germany) has been used to determine the precise and reliable shade matching for natural teeth and ceramic restorations. It was also used to evaluate the color stability of the crowns before and after thermocycling and the chewing simulator. The digital spectrophotometer measured the wavelength range from 400 to 700 nm and used LED technology, which was unaffected by the environment.

20 teeth with complete crowns were extracted and stored in sterile saline. The debris and surface pigments were removed with an ultrasonic scaler. The samples were randomly divided into 4 groups (n = 5): the PL group, the CH group, the 16 μg/mL AgNPs-PL group, and the 32 μg/mL AgNPs-PL group. The color values of the samples were measured by a digital tooth shade determination device (VITA Easyshade Compact, VITA Zahnfabrik, Bad Sackingen, Germany) in the same room. After the initial color measurement, the teeth were prepared with ProTaper NEXT system and filled with the above medicaments. And the change in color was measured at each time node (1, 3, and 9 days). The color assessment was reported using the L*a*b* system. In each analysis, the evaluation was performed in three replicates for each tooth and then averaged. Next, the tooth discoloration (∆E) was calculated according to the equation of ΔE* = ([L*1-L*0]² + [a*1-a*0] ² + [b*1-b*0] ²)^1⁄2, where L* denotes the lightness ranging from black to white, a* indicates the redness/greenness, and b* shows blueness/yellowness. Values that are clinically acceptable for color changing and perceived by the human eye are around 3.3 for ∆E*. The color change values between 1 day and initial color baseline, 3 day and initial color baseline, 9 day and initial color baseline were calculated.

Images of the stained specimens were taken with a reflex camera (Canon EOS 600D, Japan) using standardized conditions.
Color measurement on an area of 5 mm diameter was done using a spectrophotometer (VITA Easyshade Compact, VITA Zahnfabrik, Germany). The color measurements were performed before and after staining to find the difference in stain and, where brushing took place, readings were taken after brushing. Values were recorded using the Hunter L*a*b* color scale, which is a color space with coordinates for lightness (white–black, L*), where the maximum for L* is 100 (a perfect reflecting diffuser) and the minimum would be 0 (black). The scale also represents redness–greenness (a*), where negative a* is green and positive a* is red, and yellowness–blueness (b*), where negative b* is blue and positive b* is yellow.
ΔE is the color difference between initial situation (before staining) and treated specimens (after staining or staining and brushing).
Statistical analyses of the ΔE mean values for different beverages were conducted by one-way analysis of variance with post hoc Tukey's honestly significant difference test and Levene's test for analyses of homogeneity of variance (Origin2019b, OriginLab Corporation Company, United States). The level of significance α was set to 0.05.