The present invention relates to a novel insertion material intended for widening the gingival crevice. According to the invention, this material consists of a hydrophilic paste comprising, expressed as percentage by weight relative to the total weight of the material:between 5 and 15% of an astringent；between 25 and 50% of a specifically chosen texturizing agent；between 30 and 60% of water； andbetween 0 and 20% of a humectant；the total amount of water and humectant being between 35 and 65% by weight relative to the total weight of the material；said insertion material having the following release profile for the astringent:less than 20% of astringent released after 5 min；less than 40% of astringent released after 10 min；less than 50% of astringent released after 15 min；less than 60% of astringent released after 30 min；less than 80% of astringent released after 60 min.
