The treatment of proximal caries has changed during the last decade. The present study evaluates a recently developed material, applied in box-only preparations in primary molars. At the twelve-month evaluation of this clinical study, it became obvious that Dyract can be an alternative for Tytin in the primary dentition, though there is some change in color of the Dyract material. In time, the marginal adaptation of Dyract seems to improve. The preparation time for both materials is comparable. The total treatment time of box-only Dyract restorations (including an occlusal sealant), however, is longer compared to conventional class II Tytin restorations. Although in both groups radiolucencies were found at the baseline radiograph evaluation, no sign was found of secondary caries. One recurrent caries lesion was found adjacent to a Dyract restoration. It should be emphasized that one-year data do not indicate the longterm success of restorations.