Infiltration: Ultraconservative Management of Hypomineralization
The resin infiltration technique was originally introduced with the aim of filling the intercrystalline spaces with a low-viscosity resin, so as to arrest non-cavitated carious lesions (1-3). A conventional sealant remains on the enamel surface as a covering resin coat with relatively weak retention, while the resin infiltration creates a diffusion barrier within the enamel lesion, thereby reinforcing the demineralized enamel structure with the resin matrix, and preventing further cavity formation (4-7). The effectiveness of infiltrant resins to penetrate into natural carious lesions, almost to the DEJ, as well as to slow lesion development in cariogenic conditions, has been demonstrated (5-7).
Over the years, the efficacy of resin infiltration on masking white spot lesions has been shown under laboratory and clinical conditions (8-10). More recently, laboratory research has shown promising results on developmentally hypomineralized enamel lesions, which affect the full tissue thickness. In hypomineralized lesions associated with posteruptive breakdown of enamel, infiltration of the lesion prior to composite resin restoration may also improve the bonding efficacy (11).
This case report presents an ultraconservative treatment approach utilizing resin infiltration in combination with resin composite in the esthetic management of hypomineralized maxillary incisors.
A 9,5-year-old patient, presenting with hypomineralized lesions on 12, 11, 21 and 22. Similar lesions with enamel loss are present permanent molars, and to a lesser extent, on premolars. The parent refused the failing resin composite restoration to be removed completely.
Preoperative view of maxillary incisors. The photographs were taken with Ring Flash (Left), Cross-Polarization (Middle) and Lateral Flashes (Right), respectively.n
The extent of posteruptive breakdown can be appreciated under unilateral illumination. The teeth were cleaned with non-fluoride prophy paste prior to isolation.n
The infiltration technique should be applied under strict isolation. Inversion of the rubber dam is not an effective method to expose cervical margins in ICON cases, particularly in children and adolescents. In this case, the ligating floss was suspended to the rubber dam frame to maintain a stiff, proper retraction throughout the procedure.
The first round: Application of hydrochloric acid (ICON-etch): Following an application time of 2 minutes, the acid should be rinsed off for at least 30 seconds.n
View of lesions thoroughly dried with compressed air.
Visual inspection after 30 second application of ethanol (ICON-Dry). Thereafter, the teeth should be thoroughly dried with compressed air.
Repeating procedural steps. In this case, Hydrochloric acid was applied three times.n
View of the lesions after each etching episode.
Combined view of the etching and ethanol-drying steps. In the last episode (right), the whitish opaque lesions have diminished significantly.
Application of the infiltration resin (ICON infiltrant).
Light curing of each tooth for 40 seconds.
Reapplication of the resin infiltrant.
Final view of infiltrated lesions. The failing composite was reduced to an acceptable anatomic contour.
While all incisors have experienced enamel loss to varying extent, those on 11 and 21 need to be restored with resin composite.
Application of an adhesive resin, followed by placement of a thin layer of enamel composite on central incisors.
View of the incisors immediately after placement of the composite.
Immediate postoperative view of the lesions under different lighting conditions: Ring Flash (Left), Cross-Polarization (Middle) and Lateral Flashes (Right).
Comparing preoperative and Immediate postoperative view of the lesions under different lighting conditions.
View of teeth at two-week recall.
Two-week postoperative view of the teeth under different lighting conditions: Ring Flash (Left), Cross-Polarization (Middle) and Lateral Flashes (Right).
Comparing immediate postoperative and two-week postoperative view of the lesions under different lighting conditions.
Comparing Preoperative, Immediate postoperative and two-week postoperative view of the lesions under different lighting conditions.
The outcome is imperfect, but quite acceptable for a no-prep approach. Further additive restorative treatment can be considered.