14 Nov Teeth whitening, between dental aesthetics and iatrogenesis
Teeth whitening is an increasingly requested treatment at specialised practices, as patients are increasingly interested in the aesthetic side of restorative dentistry. The currently available range of products, based on carbamide peroxide or hydrogen peroxide, has allowed obtaining certain favourable therapeutic effects; the improvement in the colour of natural teeth is achieved by reducing saturation, by increasing brightness and by changing the surface texture of the enamel.
Patients assess the procedure in terms of the dental aesthetics shown in photos or seen at their friends, often forgetting that this is a medical procedure with individual biological consequences that are difficult to predict initially. Here are some of those:
1. Peroxides change the surface texture of tooth enamel
Whitening gels have an acidic pH and they cause the surface demineralization of the enamel, reduce the concentration of calcium and phosphates (saturation), decrease the microhardness and the abrasion resistance of the enamel. It is deemed that only gels based on carbamide peroxide, with a low concentration (10%), do not cause changes in the surface structure of the enamel, following an exposure of up to 5 weeks; this is the only safe, conservative and efficient method.
2. Peroxides penetrate teeth down to the dental pulp
This is the reason behind the onset of sensitivity to thermal agents or even spontaneous pains following whitening treatments, especially in the case of teeth showing cervical lesions, erosions, extended fillings or cracks in the enamel. When combined with an acidic pH, pulp lesions may be severe and caution regarding the vital teeth is advisable. Teeth whitening must be followed by a treatment for neutralising the acidic pH with fluorinated gels or potassium nitrate, in order to diminish painful sensations.
3. Whitening gels do not influence the fillings or existing prosthetic works.
Therefore, these should be replaced after approximately 3 weeks, because they will become visible, given the change in the colour of the adjacent enamel. The replacement cannot take place earlier, because the peroxides decrease the adherence of the composites to the enamel surface. Furthermore, if the teeth return to the original colour within 6 months, due to food or smoking, the filling will become visible once more and will require a new enamel whitening treatment. As such, patients may enter a vicious circle that will be difficult to escape.
4. Whitening gels cause gingival lesions
These may be caused by simple burns, desquamations, dysphagia, up to the potentiation of the mutagenic effects or certain proved carcinogens (smoking). This is why we recommend the total cessation of smoking during the whitening treatment and we also entirely contraindicate it during pregnancy and breastfeeding.
5. The effect of the whitening treatment with peroxides cannot be guaranteed
If the patient has a highly mineralized dental structure, the gels cannot succeed in inducing significant whitening, sometimes leaving behind only white stains (in demineralized areas).
Although chemical teeth whitening may provide a special satisfaction to the patient, it must be viewed as a medical procedure, performed following a well-stated diagnostic, in the practice.
In order to avoid such adverse effects, we recommend starting with a professional brushing, removing the interdental stains by means of air-flow and only then establishing customised aesthetic needs. Often, this procedure provides a significant and sufficient change in terms of shade.
At Excedent dental practice, we provide you with the possibility of obtaining outstanding outcomes through minimally invasive and customised minimally invasive methods, as well as through dental aesthetic services at the highest quality standards.
EXCEDENT – A smile for you!