The main thing to keep in mind is that you should not overdo the whitening and the teeth should look natural. 

However, we use the sponge tool to unsaturate the color and the Dodge tool to lighten.

In this lesson, you will learn how to have pearl white teeth using Photoshop, but I wish there was a permanent and physical way, and not just in Photoshop! 

Because this problem often occurs during photo editing or editing in Photoshop, there is more than one way to do this.

Teeth whitening in Photoshop

1. Open the photo of the person (or animal) whose teeth need to be slightly whitened. If you would like to join me, download this free photo from Unsplash titled Laughing Lion by Lemuel Butler. The lion tooth is orange-yellow, but it will soon show you a Hollywood smile. This method also works on humans!

2- When editing photos, I always suggest working on a copy layer. Hold Cmd + J on Mac and Ctrl + J on Windows to make a copy like your photo appear in the new layer. I rename the copy layer as “Image Edit”.

3. Select the Sponge tool.

This tool may be under the Dodge tool in the toolbar.

4- We intend to use this tool to eliminate or unsaturate tooth color. In the tool settings at the top of the screen, set the Mode to Desaturate and Flow to 100% and disable Vibrance until the checkbox is empty.

5. In the settings section, select the right size brush tool to draw on the teeth. Choose a brush with a soft edge (or 0% hardness). It is necessary to enlarge and reduce the brush when working on the teeth. One shortcut to increase the size of a brush (on any tool that deals with the brush) is to press the right or [bracket] key and to decrease the size of the left bracket or [press].

6. Zoom in on the image so you can see the tooth clearly.

7- Using the sponge tool, make the pen small and large whenever necessary. You need to make sure that the color change is only on the teeth and not on the tongue, gums or milk hair.

Everything looks better now, and that’s just because the Desaturate is set to the maximum value. Continue to work to eliminate the yellow saturation of all teeth. Do not forget that the back teeth should not be as white as the front teeth because of the shadow on them, but their yellowness should be taken.

8- When you have unsaturated the color of all teeth with desaturate, it is time to whiten them. Select the Dodge tool.

9. In the Tool options bar, select a small soft brush again. Remove the brush that is slightly larger than the tooth. Set the Range in the toolbar to Midtone and Exposure to 15%. Also check the Project Tones tab in the same bar. This helps make things look a little more natural and preserves shadows and some textures.

10. Using the Dodge tool, work around the milk tooth and enlarge and shrink the brush again when necessary. This tool has an increasing effect, that is, every time you release the mouse and start retouching, the amount of Dodge increases and increases. If the tooth becomes very white, you can go back by pressing Cmd + Z on Mac and Ctrl + Z on Windows. Or you can reduce all editing effects by going to Edit> Fade Dodge Tool.

On the left you can see the milk tooth before editing and on the right after editing.

This Photoshop method can be applied to human teeth in exactly the same way. What you should avoid is too much light and shine due to the whiteness of the teeth, but a little whitening is not a problem.