ObjectiveThe pulpal response to Hoffmann’s Pulpine mineral (PMIN) and Pulpine NE (PNE) was compared to mineral trioxide aggregate (MTA) when used as pulpotomy materials in immature permanent teeth in dogs.Materials and methodsImmature premolars were randomly divided according to the observation period into three equal groups (n= 24) (10 days, 30 days, and 90 days) then furtherly subdivided into 3 subgroups according to the material used. Histopathological analysis regarding inflammatory cell infiltration and dentin bridge (DB) formation was done. Immunohistochemical analysis was performed using osteopontin marker.ResultsThe results showed that after 90 days, both MTA and PMIN subgroups had 100% complete thick DB without inflammation in 87.5% of the samples, while the PNE subgroup failed to form DB in 37.5% of the samples and 50% of samples showed thin initial DB with heavy inflammation in 62.5% of the samples. There was no significant difference between MTA and PMIN, while there was a statistically significant difference between PNE and the two other subgroups in DB formation and inflammatory cell infiltration (P> 0.05). After 90 days, MTA showed the highest mean value of osteopontin positive fraction area followed by PMIN without statistically significant differences, while the least value was recorded in PNE subgroup with statistically significant difference with the remaining subgroups (P< 0.05).ConclusionPMIN is a promising alternative to MTA when used for pulpotomy.Clinical relevanceVital pulp therapy in immature teeth can be done using PMIN as an alternative to MTA.