Initial caries infiltration under wet conditions

Objectives: To study the infiltration of resin into initial caries lesions (white spot and brown spot lesions) under wet conditions to mimic oral milieu without rubber dam application. Methods: 22 extracted human premolars exhibiting white or brown spot initial caries lesions (ICDAS II code 1 or 2) were randomly divided into three groups. Before application of the resin all teeth were stored in 1% sodium fluorescein solution. Group I (6 teeth) was treated with resin (ICON ^Ò, DMG, Hamburg, Germany) according the manufacturers instructions under dry conditions. Group II (9 teeth) was kept in a moist chamber for 10 min. and then treated with resin. Group III (7 teeth) was kept for 24 hrs. in a moist chamber and then treated with resin. All teeth were embedded and serial sections were cut through the lesions. The sections were investigated using polarized and fluorescence microscopy. The infiltration of resin was evaluated qualitatively and quantitatively using morphometric methods. Results: The results showed a complete infiltration of the whole lesion in group I and II. However, in group II the infiltration was irregular. Group III showed a complete infiltration of the body of the lesion, but a very distinct surface zone with no infiltration of the resin. Conclusions: Under wet conditions initial caries lesions are not fully infiltrated by the resin. This could increase the risk of further caries progression.