A phosphonate salt for use in a dental treatment, in particular in a root canal treatment, for the manufacture of a pharmaceutical preparation, in particular as decalcifying agent and a pharmaceutical preparation for use in the dental treatment comprising a phosphonate salt and/or a phosphonate salt and a hydroxide compound in solid form are provided. A method of producing a pharmaceutical preparation and a kit of parts (1, 1′) for manufacturing a pharmaceutical preparation for use in the dental treatment are provided.
