Fig.1
Female patient, 26 years old, unhappy with the presence of unaesthetic spots on teeth of the anterior-superior sector (13-23). The physical and clinical history evaluation led to the diagnosis of fluorosis and demineralizations after removing the orthodontic appliances . Tooth 21 had suffered a mechanic iatrogenic aggression. Microabrasion enamel technique followed by resin infiltration technique and composite restoration were performed.

Fig.2
The most important factors contributing the success of enamel microinfiltration are the location and depth of the enamel stain or defect. The alteration must be restricted to enamel tissue, without involvement of the dentin. Cross-polarized photography makes it easy to eliminate unwanted reflections on the teeth that are caused by the flash. In this way, it simplifies the monitoring and evaluation of the extent of demineralization and decalcification of white spot lesions.

Fig.3
Rubber dam isolation is highly recommended. It was performed in order to have a dry and more comfortable working space, tissue protection, and acceptable retraction. After teeth isolation chemical and mechanical abrasion was performed (Opalustre® – Ultradent) . Once these lesions affect the enamel’s sub-surface, cavitation may occur.

Fig.4
After enamel microabrasion.

Fig.5
After having properly cleaned tooth surfaces, enamel overlying the lesion was etched with with 15% hydrochloric acid etching solution (ICON etch®, DMG) and rubbed for 2 minutes. The acidic gel was then rinsed with air-water spray for 30 seconds and dried.

Fig.6
An ethanol solution (ICON dry®, DMG) is used to perfectly dry the surface. After drying, water was applied and the visual aspect of the lesion was checked: at this stage, the spot should have almost disappeared. If not and where the removal of the surface layer appeared insufficient, the etching step was repeated up to 3 times and the etching gel was applied with gentle pressure in a circular motion.

Fig.7
The transparent hydrophobic infiltration resin (ICON infiltrant®, DMG) was carefully applied and rubbed onto the etched area with the applicator for 3 min, slightly dried with compressed air for 10 s, light-cured for 40 seconds and reapplied a second time for an additional 1 minute to compensate for polymerization shrinkage.

Fig.8
Before removing rubber dam cervical and interproximal resin excess was removed using the Eccesso instrument (LM Arte powered by Style Italiano). The treated surfaces were then finished and polished under irrigation.

Fig.9
In a second office visit we restored with resin composite the area where there had been a loss of volume due to the microabrasion.

Fig.10
Direct enamel composite restoration (Enamel Plus HRi _UE2).

Fig.11
Application of glycerin. A thin (approximately 1–3μm) layer of non-polymerized resin on the surface of a composite material is produced as a result of the action of atmospheric oxygen. Viscous glycerin-based gels are designed to prevent the formation of an oxygen inhibited layer on the surface of resin materials when they are polymerized.

Fig.12
The final curing is completed through the glycerine, which is then rinsed off prior to finishing and polishing. The result is a harder composite surface that is easier to finish.

Fig.13
Most of the final anatomical features were created with a coarse or mediumcoarse disc (Sof-Lex, 3M, USA). For ultra high gloss, ENA Shiny diamond paste was applied with a felt wheel.

Fig.14
Final aspect before rubber dam removal.

Fig.15
Right after rubber dam removal.

Fig.16
5-year follow-up.

Fig.17
Given the minimal loss of substance due to the microinvasive restorative procedure, the patient was extremely satisfied with the result.

Conclusions

Based on the satisfactory results obtained, we conclude that the resin infiltration technique is very promising, and could be considered as a minimal invasive procedure. However, long term follow-up evaluation must be carried out to affirm the efficacy and durability of this type of treatment.

Bibliography

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4. Paris S, Meyer-Lueckel H. Masking of labial enamel white spot lesions by resin infiltration—a clinical report. Quintessence Int. 2009;40: 713-718