Influence of application time on penetration of an infiltrant into natural enamel caries

Caries infiltration is an innovative approach to treat medium stages of caries that bridges the gap between preventive and invasive measures, whereby hard tissues are preserved. Special low viscosity resins (infiltrants) showed almost complete penetration into natural lesions when applied for 5 min. Since shorter application times seem to be clinically more feasible, the aim of this in vitro study was to compare the penetration of an infiltrant (Icon pre-product; DMG, Hamburg, Germany) into natural caries lesions after various application times.

Extracted permanent human posterior teeth showing non-cavitated proximal caries lesions were infiltrated for either 0.5, 1, 3, or 5 min (n=20) and light-cured. Specimens were prepared and lesion (LD) as well as penetration depths (PD) were analysed using dual fluorescence confocal microscopy.

PD [median (Q25;Q75)] at maximum LD after 0.5 min [159 (27;340) μm] and 1 min [152 (69;375) μm] were significantly lower compared to those after 3 min [414 (338, 518) μm] and 5 min [407 (332;616) μm] (p<0.05). Deep lesion parts (PD>500 μm) could be penetrated almost completely after 3 min [98 (88;100)%] and 5 min [100 (81;100)%] application.

Thus, 3 min application of an infiltrant seems to be sufficient to achieve an almost complete penetration of enamel caries.