PROBLEM TO BE SOLVED: To provide base materials for dental impression materials capable of imparting excellent impression accuracy in a dental impression material, and capable of imparting excellent handling properties at the time of kneading a base material for dental impression materials with a cure material and of using a dental impression, and to provide dental impression materials comprising the same.SOLUTION: In one aspect, the present invention provides a base material for dental impression materials which is a base material for dental impression materials comprising water, alginate, and a filler, the filler comprising diatomite and a silica particle, and the mass ratio of the diatomite in the base material for dental impression materials and the silica particle being 4/1 to 1/1. In another aspect, a dental impression material comprising the base material for the dental impression materials and a cure material is provided.SELECTED DRAWING: None【課題】歯科印象材における良好な印象精度、並びに歯科印象材用基材と硬化材との練和時及び歯科印象材の使用時における良好な取扱い性を与えることが可能な歯科印象材用基材、及びこれを含む歯科印象材を提供する。【解決手段】一態様において、水、アルギン酸塩、及びフィラーを含む歯科印象材用基材であって、該フィラーが、珪藻土と、シリカ粒子とを含み、歯科印象材用基材中の該珪藻土と該シリカ粒子との質量比率が４／１～１／１である、歯科印象材用基材が提供される。別の態様において、該歯科印象材用基材と、硬化材とを含む歯科印象材が提供される。【選択図】なし
