In recent years the concept of minimally invasive dentistry has offered a more conservative approach to restoration of teeth with caries lesions. Several techniques have been suggested for treatment of proximal lesions, but their results have been less than ideal. The aim of this article is to present a new technique for ultraconservative restoration of small interproximal caries lesions that avoids the disadvantages of both the tunnel and the proximal slot restorative techniques. Two cases, of patients with high and low caries risk, are presented to illustrate the technique. The proposed technique can be considered the most conservative alternative to conventional Class 2 or slot-cavity treatment approaches. Keywords: caries lesion, caries risk, fluoride, minimally invasive dentistry, proximal lesion, resin composite