Pulpotomy materials have been used in dentistry with the expectation of induction of reparative dentin for maintain of pulp vitality in mature permanent premolar tooth. However, few histopathological studies have been performed in vivo with healthy tooth. This study was perfumed to examine whether pulpotomy with calcium-silicate based BiodentineTM could induce reparative dentin formation without eliciting adverse side effects of premolar teeth, in vivo. In this study, pulpotomy was performed on upper left first premolar tooth (which is needed to extract for aesthetic reason) with BiodentineTM and then the quality and quantity of reparative dentin was assessing by histological analysis at 28 days. It was found that the thickness of reparative dentin formation was 1.4 ± 0.4 µm that completely covers the exposed pulp tissue. It can be concluded that BiodentineTM is capable to induce pulpal wound healing and reparative formation in the exposed teeth without affecting the normal function of the remaining pulp.