Introduction: ERRM is a new bioactive cement that is similar to the widely used mineral trioxide aggregate (MTA). These 2 materials simulate dentin in various properties, which may be considered a preferable material for clinical indications of dentin-pulp complex regeneration such as direct pulp capping. The aim of the present study was to compare the response of the pulp-dentin complex in human teeth after direct capping with ERRM cement with that of MTA. Methods: Pulps in 15 caries-free maxillary and mandibular permanent intact human premolars arranged for extraction for orthodontic reasons were selected & mechanically exposed and assigned to 1 of 2 experimental groups, MTA or ERRM, and 1 control group. Each group has 5 samples. Assay of periapical response and clinical examination were performed. After 3 weeks, the teeth were extracted, stained with hematoxylineosin, and categorized by using a histologic scoring system. Results: The majority of specimens showed complete odontoblastic layer formation and an absence of inflammatory pulp response. Statistical analysis showed significant differences between MTA& ERRMwhen compared to these 2 ERRM showed inferior result outcome. Conclusions: Within the limitations of this study, ERRM may be considered an interestingalternative to MTA in pulp-capping treatment during vital pulp therapy. ERRM also has good results but it is inferior when compared to MTA.