Fig.1
A 29-year-old male visited our dental office and asked us to figure out a solution for his teeth discoloration issue, preferably avoiding the drilling approach. Patient was placed in occlusion before bleaching with cheek retractors.

Fig.2
A pilot study was conducted to see the effect of the application 16% CP (Teeth Whitening Gel, White Dental Beauty) on sound enamel. Representative SEM images at 16000× magnification (a) sound enamel; (b) 16% CP (Teeth Whitening Gel, White Dental Beauty), application period similar to 2 weeks. SEM images showed no major changes to enamel topography after bleaching.

Fig.3
A pre-operative picture is mandatory to select the proper shade and to assess the evolution of the bleaching treatment (the initial shade obtained in this case was A3.5 VITA classical in the cervical region and A3 VITA classical in the middle and incisal regions).
This picture was taken with the help of Smile Lite MDP device and a Note 9 smartphone in order to compare color deviations between the shade guide and the tooth. Six LEDs on each side of the lateral lights were turned ON and covered with the white diffusers, giving the twin flash effect. Two retractors and one black photographic background (Flexipalette, Smile Line, Switzerland) were used. A3.5 and A3 samples were placed near the natural tooth with edge-to-edge position.

Fig.4
A polarized picture can be of great help in showing the difference in color compared to the shade guide, and to better frame the issue. Shade was obtained without reflection, and this could be possible by using the polarizing filter mounted on the central light of the Smile Lite MDP device (Smile Line, Switzerland). Only the central light must be ON in this kind of picture.

Fig.5
Another polarized picture for the patient placed in occlusion before bleaching with cheek retractors and two shade guide samples.

Fig.6
For at-home treatment, the CP gel is available at 5%, 10%, and 16% concentrations, along with 6% HP (Teeth Whitening Gel, White Dental Beauty). It is important to note that White Dental Beauty gels all feature NOVON® patented technology for optimum performance and decreased sensitivity. The 5% CP Mild was designed specifically for patients with enhanced dental sensitivity. The 6% HP is a fast-acting formula with an application time of as little as 30 minutes per day. In addition, the 16% CP and 10%CP can be applied by day or night.

Fig.7
In this case, a 16% CP (White Dental Beauty, Optident, UK) was chosen to be applied 2-4 hours/ day for 2 weeks.

Fig.8
The patient was instructed how to insert the bleaching trays and to apply the 16% CP gel in the amount of a drop per tooth (the size of half rice grain). Syringes could be delivered to the patient for a period of one week.

Fig.9
Final result after 7 days of bleaching: The color obtained was verified with the same shade guide, and the most suitable was A1 from VITA classical. The difference between the initial shade guide A3.5 and the A1 shade guide could be noticed very well, which can be considered a good result visually and clinically.

Fig.10
Details from a polarized picture comparing the final color obtained with the initial A3.5 shade VITA classical shade guide after 7 days of at-home bleaching.

Fig.11
The final result, after 7 days of bleaching with a polarized picture, was satisfying for the patient. To counterbalance color rebound, as no increase in sensitivity occurred, another week of at home whitening was done to stabilize the result.

Fig.12
Another polarized picture comparing the final color obtained with the initial A3.5 shade VITA classical shade guide.

Fig.13
Final result after 14 days of bleaching. The color obtained was verified with the same shade guide, and the most suitable was B1 from VITA classical. The difference between the initial shade guide A3.5 and the B1 shade guide could be noticed very well, which can be considered a successful outcome visually and clinically.

Fig.14
Beneficial effect after 14 days of bleaching with 16% CP.

Fig.15
The final result, after 14 days of bleaching with a polarized picture, was pleasing for the patient.

Fig.16
Details from a polarized picture comparing the final color obtained with the initial A3.5 shade VITA classical shade guide after 14 days of at-home bleaching. The patient was able to see the evolution of the treatment by seeing the pictures taken by the MDP device.

Fig.17
The patient was satisfied and happy with the result. Some tips were given to the patient to preserve the bleaching effects for a long period of time.

Fig.18
All stages of dental bleaching, before and after, polarized and non polarized, after one week and two weeks.

Conclusions

Home bleaching using CP at a low concentration (e.g., 16%) should be considered a good treatment alternative for in-office bleaching using HP at higher concentration (e.g., 35%). The home bleaching option using White Dental Beauty products was considered safe to treat discolored teeth and minimize tooth sensitivity. This could be explained by the presence of NOVON® technology active in all percentages of White Dental Beauty gels. NOVON® is a patented whitening compound that comprises HP, urea and sodium tripolyphosphate with an acidic pH value of 6.5. However, when NOVON® is diluted, the pH value rises to 8.5 (alkaline range).

The Smile Lite MDP device allows the use of the diffusers and polarizer filters in an easy way. As a consequence, the resulting pictures can be used to show the patient the initial situation and the evolution of the bleaching process with the artificial shade guide.
Since people perceive color differently, the use of a dental shade guide accurately determines the tooth color before and after treatment and can enhance the reliability of visual comparisons of tooth whitening outcomes.

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