Abstract : One of the ingredients that is believed to stimulate the formation of dentinal bridges is calcium hydroxide, but this material is highly toxic, the dentinal bridge that forms is porous. Therefore, alternative materials are needed to be biocompatible, such as clam shells which contain calcium carbonate that’s used as a remineralization material for hard tooth tissue. Transforming Growth Factor β (TGF-β) has a significant role in cellular signaling for odontoblast differentiation and stimulation of the dentin matrix. This study aims to determine the expression of TGF-β1 after applying green shell extract paste (Perna viridis) in inflamed Wistar tooth pulp. This research is a laboratory experimental and clinical trial research with a posttest-only control group design with 24 Wistar samples. The experimental animals were divided into 4 groups, namely: negative control, positive control group (CaOH2 application), 1st group (35% green shell extract paste), 2nd treatment group (40% green shell extract paste), be sacrificed within for 3, 7 and 14 days. Data were analyzed on experimental animals using immunohistochemical examination using ELISA. The normality test using the Shapiro-Wilk shows a significant value (p>0.05). Statistical test results using test-independent samples t-test show a value (p<0.05). Based on observation times of 3,7 and 14 days, a higher increase in TGF-β1 expression was seen after the application of 35% and 40% green shell extract paste based on histological examination and statistical tests (p<0.05). Green shell extract paste (Perna viridis) 40% and 35% significantly has higher effectiveness as dental pulp protection agents with increased TGF-β1 expression.