The cavity was then irrigated with bi-distilled water kabipac 9% and then dried. At that moment, the entrance to the canal was filled with glass ionomer cement Vitremer.This was achieved with the purpose of creating a physical barrier to avoid micro-filtrations as well as internal resorption. Sodium perborate mixed with peroxide Dermocleen 2.53.5% was prepared until obtaining a thick consistency resembling «damp sand». It was then brought to the pulp chamber with a 33L spoon SS White; once the whitening agent was in place, the instrument was introduced at red hot heat, this allowed for oxygen release.
En ese momento, se obturó la entrada del conducto con cemento de ionómero de vidrio Vitremer con el propósito de crear una barrera física que evite la microfiltración e impida la reabsorción interna, y se preparó el perborato de sodio mezclado con agua oxigenada Dermocleen 2.5-3.5% hasta obtener una consistencia espesa tipo «arena húmeda» para llevarlo a la cámara pulpar utilizando una cucharilla 33L SS White; una vez colocado el agente blanqueador, se introdujo al rojo vivo el instrumento caliente, lo que permitió la liberación de oxígeno.