PROBLEM TO BE SOLVED: To provide a dentistry repair kit excellent in repair of dentin hardness by remineralization for dentin (particularly dentin decalcified).SOLUTION: A dental repair kit consists of a pretreatment material (A) containing an acid (a-1) which generates a poorly water soluble calcium salt, and a calcium phosphate composition (B) used to cover the dentin which is applied with the pretreatment material (A), wherein the calcium phosphate composition (B) contains a calcium phosphate mixture (b-1) which hardens by reacting with water, and water (b-2).