inclusion criteria:  Child from 7 to 12 years old presenting a mild to moderate HIN on at least one permanent first molar requiring reconstitution. Child presenting a state of anxiety compatible with the provision of oral care (score on the Venham scale modified by Veerkamp below 2). Child affiliated to or benefiting from a social security scheme. Free, informed and signed consent by the parent(s)/holder(s) of parental authority and the investigator (at the latest on the day of inclusion and before any examination required by the research). Oral consent of the child.  Non-inclusion criteria:  Child presenting an allergy or a history of allergy to one of the constituents of biomaterials Child with fluorosis Child with amelogenesis imperfecta  Child with pacemaker (contraindication to CAD/CAM)  -