Tooth discolouration is a common aesthetic concern that can complicate restorative procedures. Whether caused by trauma, fluorosis, tetracycline staining, or aging, masking discolouration requires a strategic approach that balances material selection, shade management, and clinical technique.
Several techniques can be used to mask discolouration. Before choosing the best strategy, it's essential to identify the type of discolouration:
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Extrinsic stains, such as from tobacco, tea or coffee, are usually superficial and can be removed with a simple professional tooth cleaning. Ultrasonic devices or air polishing devices can be used.
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Intrinsic stains are deeper and may be the result of trauma, systemic medication or developmental defects. They can be localised or generalised. These stains will need another strategy to mask or remove them
Tooth bleaching
Whitening the teeth before the IMT procedure can improve the outcome of the future restorations. establish a lighter baseline shade, after which restorations can be matched more accurately. Especially in the case of mild discolorations, it also helps to even out the tooth colour, making the teeth appear more uniform. However, results may vary. Tetracycline discolourations tend to respond less to tooth whitening.
Courtesy of Dr Sebastion Däröste, Sweden
Hybrid IMT techniques
Tooth structure is naturally polychromatic — dentine is more opaque and chromatic, while enamel is translucent. Polychromatic allow for better control of light transmission and reflection, making it easier to mask colour differences. While IMT usually is a monochromatic technique, hybrid methods can be used to make polychromatic restorations
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Selective removal
Depending on the depth of the stain, a local cutback can be applied to remove the dark tissue and to create space for a thicker layer of overlying composite. An opaquer composite, such as the Essentia Masking layer or the opaque shades of
G-ænial A’CHORD and G-ænial Universal Injectable can be used for the localised masking
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Cut-back approach
In the cut-back technique, an additional mould is created after reducing the enamel layer—either directly on the model or digitally, followed by 3D printing of the modified version. This secondary mould is first used to apply an opaquer composite layer. Afterward, the original full-contour mould is used to inject a more translucent enamel shade on top, helping to recreate natural light reflection and depth.
A cutback can also be performed intraorally immediately after the injection of the most opaque shade. After the cutback, the mould is repositioned, allowing for the application of a more translucent top layer. However, this approach increases chair time and is recommended only for minor cutbacks.
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Palatal stent technique
In the palatal stent technique, an additional palatal silicone key is created to create the palatal surface first. Once this is finished, a regular composite can be used to place to the deepest dentine layers and to give shape to the mamelon structure with a freehand technique. Hereafter, the restoration is completed by injecting the top layer.
Combination with ceramic restorations
In cases of severe discolouration, it may be more effective to mask the underlying shade with an indirect ceramic restoration. Ceramics typically offer greater opacity than composites—zirconia being more opaque than lithium disilicate. To preserve a natural appearance, feldspathic veneering ceramics can be used. It's advisable to use opaque or neutral-shade resin cements to prevent colour show-through.
For remaining teeth without discolouration, the IMT technique remains a suitable option for build-up
Tip:
Discuss expectations clearly before final cementation. Colour perception is subjective, so your patient might have a different opinion. It’s also advised to evaluate the tooth colour together with your patient, under different lighting.