External Tooth Whitening

17 Nov 2015 - 34731

Tooth whitening has become one of the most frequently requested procedures for both aesthetic and cosmetic dentistry. External tooth bleaching is a conservative, non-invasive and well-documented technique (1) with a high sucess rate (more than 90% satisfactory results have been reported (2)).

Hydrogen peroxide (HP) is the active agent most frequently used in whitening products which releases oxygen and other free radicals. These molecules attack the long-chained, dark-colored chromophore molecules and split them into smaller, less colored, and more diffusible ones (3). HP is delivered direcly or as carbamide peroxide (CP). CP is a stable complex that breaks down in contact with water to release HP.

HP or CP in different concentrations have been used to treat tooth discoloration. However, 10% Carbamide peroxide is the most commonly used due to its effectiveness, quickness and few side effects while achieving desirable results. Side effects include tooth hypersentivity, gingival irritation, tooth surface roughening and softening or degradation of marginal sealing of composite restorations. However the degree of these side effects is directly releated to the concentration of the peroxide bleach component, duration of the treatment, and non-bleach composition of the product used (4).


A non-smoker 40 years old male patient was evaluated with the chief complaint of discolouration of teeth. Good periodontal health , no gingival recessions, decay or history of tooth sensitivity was reported.

An External Tray-Based Tooth Bleaching -known as “at-home” or “night-guard”- was proposed for this patient.


During the first appointment, before the start of the treatment a professional tooth cleaning was done.

Fig. 1

After professional tooth cleaning alginate impressions were taken

Fig. 2

And study models were made for the manufacture of the bleaching trays for both maxillary and mandibular arches.n

Fig. 3

Before the custom tray is vacuum formed some adjustments may be made on the model. Tip: Scracth the model 0,2mm apical to the cervical area (CAL) to obtain extra-seal of the custom tray and helping keep the gel away from the gums and the ingress of saliva that may wash out the bleaching gel from the tray.n

Fig. 4

Tip: Reduce the overall thickness of the model to dental arches to facilitate tray adaptation while vacuum formed.

Fig. 5

The buccal surface of models teeth can be blocked out to create a reservoir for the bleaching gel even when there are no differences in the rate of bleaching with or without reservoirs (5).n

Fig. 6

Then 0,5mm thermo-forming sheets are used to fabricate both trays.

Fig. 7

Tip: Permanet marker is used to highlighting the trays limits and Scallope the tray borders to follow gingival profile to minimize tissue contact.

Fig. 8

If short lasting product is gonna be used cut the custom tray 1 mm beyond CAL, if long lasting products 1,5 mm is required.n

Fig. 9

Bleaching trays ready to use for the patient.

Fig. 10

During the second appointment, Initial photographs are taken with and without vita shade tabs. Tip: desaturated Crosspolarized pictures help us on iditifying the value of the teeth.n

Fig. 11

B3 Vita Shade was established as the starting point, color assesment is preferrably done with the aid of a neutral gray contrastor, this helps to eliminate the black effect of the oral cavity, thus giving a better perception of the overall color.

Fig. 12

Custom trays are checked for accuracy of fit, tissue adaptation, retention and occlussion.

Fig. 13

Patient is shown how to insert the custom trays and to apply 10% Carbamide peroxide gel (White Dental Beauty Optident Ltd) in a drop per tooth.

Fig. 14

Tip: Patient is instructed to brush and floss the teeth before bleaching since bacterial plaque has low pH and disables the bleaching gel. Patient is also instructed to thoroughly dry the teeth where the gel will be applied. to minimize the effect of salivary peroxides.

Fig. 15

Instructions should also include tray wearing times, possible side effects and how to deal with them. According to manufacturer’s instructions 10% Carbamide peroxide gel should be worn for 2 to 4 hours a day.

Fig. 16

The change in colour is weekly monitored with a Vita shade scale aligned according to brithness as recommended by the manufacture.

Fig. 17

Black & white Vita shade scale aligned according to brithness as recommended by the manufacture.

Fig. 18

Tip: Upper arch was treated at a time to preserve the opposing arch as a standard for latter comparison. The lenght of the treatment will vary, depending on the specific case, but usually will not taken more than 3 weeks. (First one for the upper arch, second one for the lower and one more in which both arches are treated at a time to reinforce and stabilize the final result.).n

Fig. 19

One week after the beginning of the bleaching treatment we moved from B3 Vita Shade to C1.A2.

Fig. 20

After 4 weeks of treatment the final color was classified as A1 according to Vita scale. No gingival irritation or dental hypersensitivity was reported.n

Fig. 21

Final Photographs are taken with both start and end Vita shade tabs. The patient noticed a marked improvement and was very pleased with the final outcome.

Fig. 22

Digital combination of before (right side of the image) and after (left side) of the polarized image, where it is shown how over the same gingival color dental tissues indeed have an important color change, thus assesing that they were bleached. This method is one of the most precise for color bleaching estimation.

Fig. 23

This case was performed with WDB. White Dental beauty is a product by Optident Ltd. during its development it was tested and tried by several Styleitaliano members with optimal results. For more info visit