As tooth discolorations, brown and white spots have, among ultraconservative methods of dental therapy, chemical treatments as one of the most biomimetic options due to the total conservation of remaining intact tooth substance. Knowledge of these techniques, combined with a well-defined selection of indications, often allows more invasive treatment options (composite or ceramic veneers) to be avoided.
In previous articles of the Style Italiano community, external and internal bleaching techniques have been well described. In certain cases of idiopathic spots and stains of the vital teeth, chemical treatment was proposed as the definitive therapy. Whitish and brownish stains can occasionally be eliminated by combining bleaching with mechanical abrasion treatment.
Recently, practitioners received another option to consider while treating brown/white spots: the erosion-infiltration technique.
The method, initially developed for the treatment of early caries lesions in the enamel, has the secondary effect of masking white stains because it modifies the optical properties of the tooth (ICON by DMG). After erosion conducted using a gel of 15% hydrochloric acid, the infiltration of a very low-viscosity resin (with a refraction index close to the healthy enamel) into the porosities of the body of the lesion produces a translucent enamel one again. This therapy preserves the structures of the patient’s tooth and does not cause any pain.
The infiltration technique has been widely proven to eliminate unaesthetic enamel spots, as long as the depth is correctly evaluated and the indications followed correctly; in other words, in deep lesions infiltration alone can appear to be insufficient.
Before stain treatment as a routine procedure, bleaching should be proposed for several reasons described by Jordi Manauta.
In previous published SI case studies it has been shown that, through effective bleaching, the amber spots turn into white spots which are more subject to the acid treatment of the infiltration therapy.
Concerning the white spots: bleaching reduces their opacity and the contrast between the white spots and surrounding newly bleached tissues.
A 19-year-old female patient visited our dental clinic in order to sort out the aesthetic problems connected to brownish/whitish spot discolouration in teeth 11, 33 and 42.
She had already visited the dental clinic five years ago, seeking aesthetic improvement (Fig 2, 3)
Anyway, at the age of 14 she was too young to be offered a bleaching treatment. Furthermore, we did not have experience with erosion-infiltration at that time.
Upper dental arch of the patient: a big white-amber-brownish discolouration spot on tooth 11
Lower dental arch of the patient: a medium-sized amber discolouration spot on tooth 42, and a smaller size whitish spot on tooth 33.
The patient was qualified for night-bleaching. The selected bleaching therapy was Carbamide Peroxide 10% for 14 days (White Dental Beauty, Optident, UK) during the full sleep time. No sensitivity was reported.
The smile of the patient after bleaching therapy.
The upper and lower teeth showed significantly brighter colour after bleaching therapy with Carbamide Peroxide 10% (White Dental Beauty, Optident, UK). The brownish-amber spots transferred into the white spots.
The lower anteriors were isolated with a rubber dam.
15% HYDROCHLORIC acid was applied for 120 seconds (ICON ETCH, DMG, Germany), and the surface was rubbed mechanically using a microbrush. The icon-etch was then rinsed for 30 seconds using a water spray, and the surface dried using water-free air.
Once the enamel had been eroded, the water that contained in the micropores created in the white lesions should be eliminated before the resin infiltration is carried out. Effectively, the infiltrating resin (Icon-Infiltrant) is a matrix based on hydrophobic methacrylate resin (TEGDMA). For this reason, the lesions must be desiccated beforehand. This dehydration is accomplished through the application of a solution of 99% ethanol (Icon-Dry) on the surface of the lesions. The manufacturer suggests a 30-second application of this agent, although Jordi Manauta describes a 120 s Icon-Dry application in one of his case reports published in SI.
Enamel erosion with hydrochloric acid together with ethanol application can be repeated up to four times.
The lesions appear to be much less bright and have nearly disappeared. Therefore, they are accessible for the resin infiltration. Airblow drying is then carried out in order to evaporate the ethanol.
At this point, infiltration can be performed. TEGDMA-based resin (Icon-Infiltrant) is applied. For this resin, which has very low viscosity and is water-resistant, it is recommended to allow the infiltrant to penetrate for about three minutes. A polymerization step is performed for 40 seconds. Then, a similar infiltration step is carried out for one minute, to minimise surface porosity. A last light cure procedure is then carried out with glycerin gel.
Tooth 42 after resin infiltration.
The final surface is polished with shiny goat hair brushes and 1-micron diamond paste (Enamel Plus Shiny B).
The clinical situation after deep lesion infiltration of teeth 43 and 42.
The infiltration therapy was split across two appointments to assure the patient about the effect before treating the biggest lesion on tooth 11.
At the second appointment, the lesion on tooth 11 was eroded with 15% hydrochloric acid for 120 seconds (ICON etch, DMG, Germany)
The acid was then rinsed for 30 seconds using a water spray, following which the surface was dried using water-free air.
The lesion after first application of 15% hydrochloric acid.
Preview with alcohol (ICON dry, DMG, Germany).
The application of the resin (three minutes).
The clinical situation before the final polymerisation.
The glycerin gel has been placed and final polymerisation performed.
The final result of the upper anterior teeth after resin infiltration therapy
The lower anteriors after final treatment
The final clinical result after resin infiltration therapy
The Mirror-like comparison of before (up) and after (low)
1. The dental practitioner should be aware of the minimal invasive possibilities that are available in contemporary dentistry.
2. Bleaching should be the first choice when thinking about discolouration or restorative treatment
3. Infiltration therapy should be a considered together with bleaching for the treatment of brownish/whitish spot problems.
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