INTRODUCTION: Direct pulp capping (DPC) is a procedure to maintain the pulp vitality using a material with specific properties. Mineral trioxide aggregate (MTA) is considered as a gold standard material, but it has some drawbacks. In this study, a combination of simvastatin and calcium hydroxide (SIM-CH) was used as a DPC material as it was proved that simvastatin influenced odontoblast cells differentiation. OBJECTIVE: To compare histologically the effect of the combination of SIM-CH to MTA as a DPC material in rabbits' incisor. MATERIALS AND METHODS: 32 sound maxillary incisor teeth of 16 male New Zealand white rabbits were divided into; group I received MTA, and group II received (SIM-CH) as a DPC material. Class V cavities were done in the upper incisor teeth, then DPC materials were applied. The final restoration was applied. The animals were euthanized after 1, 2 weeks. Routine histological preparation was done, Scoring system was done to evaluate the newly formed dentin. The percentage of the surface area of the newly formed dentin was assisted by histomorphometric analysis. RESULTS: Both groups showed new dentin formation. Group I reported somewhat more continuous layer of tertiary dentin than SIM-CH group. On the other hand, the dentin bridge of the SIM-CH group demonstrated more orderly organized tubules. There was a statistically significant difference regarding the histomorphometric analysis of the percentage of the surface area of the newly formed dentin of group I compared with group II (p< 0.05). CONCLUSION: SIM-CH could be a remarkable alternative DPC material.