Objectives: The aim of the present multi-center investigation was to evaluate the clinical efficacy of a strontium chloride hexahydrate containing desensitizer Hyposen (Lege Artis) over a period of 24 weeks. Material and Methods: 142 patients with hypersensitivity were included in the double-blind, randomized, comparative placebo study. Eleven different dental clinics were involved. All dentist were calibrated. Each patients exhibited at least two hypersensitive teeth with uncovered dentin surfaces. One tooth was treated with Hyposen desensitizer, the other tooth was treated with a placebo. All materials were applied as recommended by the manufacturer. Levels of hypersensitivity were assessed after 2, 8, 12 and 24 weeks by cold air stimulus and tactile stimulus with an dental explorer. Results: After 12 weeks in 102 patients (71.8%) a reduction of discomfort and pain could be observed. 24 weeks after application of the desensitizing agent in 95 patients (66.9%)a reduction of hypersensitivity could be detected. Compared with the placebo group statistical analysis showed a significant positive effect of Hyposen after 12 and 24 weeks (pConclusions: It can be concluded that using the strontium chloride containing Hyposen for the treatment of hypersensitive dentin surfaces is an easy, safe and effective alternative to other desensitizing agents and treatment procedures. Keywords: strontium chloride, dentin hypersensitivity, dentin, desensitizing agent, clinical study