Objectives: The present investigation compared and assessed the pulpal responses to castor oil versus formacresol (FC) through pulpotomy medications in deciduous teeth. Material and Methods: The present study was done on thirty-one children aged between seven and nine years with bilateral deciduous teeth that need serial extraction attending the Clinic of Pediatric Dentistry Department, Faculty of Dentistry. Every child has one or two teeth bilaterally, fulfilling the clinical and radiographic criteria for the research. The teeth were separated into two groups randomly, each with thirty teeth, rendering to the utilized pulp capping materials—the group I had been treated with FC. In contrast, Group II had been treated with castor oil. Also, two sound (Negative control) teeth were used to standardize normal pulp structure and tissue organization. Ten teeth were removed from each group at intervals of two, four, and twelve weeks. Pulpotomy procedures were done in both groups. Teeth in each group were extracted and underwent processing for histological analysis and then statistical evaluation. Results: Castor oil showed statistically significantly higher results than FC regarding pulp inflammation, soft tissue organization, and dentin bridge formation. Conclusions: Castor oil is associated with decreased pulpal inflammation and more preservation of the odontoblastic layer with enhanced regenerative tendency than FC. Clinical Significance: Castor oil is a biocompatible substance compatible with deciduous pulp tissue. Moreover, it has a strong capacity for maintaining the health and functionality of the remaining pulp tissue.

Keywords: Castor oil, Formocresol, Pulpotomy, Primary teeth, Histological evaluation.