Aim. There is an increasing interest in the application of BioACTIVE materials to achieve hard tissue formation and maintain pulp vitality. Mineral trioxide aggregate (MTA) and Biodentine (R) are BioACTIVE materials used for pulp capping. Recently, dental researchers have produced BioACTIVE glass-incorporated light-curable pulp capping material. The study is aimed at evaluating the subcutaneous connective tissue reactions to MTA, Biodentine (R), ACTIVA BioACTIVE Base/Liner. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Sprague Dawley rats. The presence of inflammation, predominant cell type, calcification, and thickness of fibrous connective tissue was recorded by histological examination 7, 30, and 60 days after the implantation procedure. Scores were defined as follows: 0 = none or few inflammatory cells, no reaction; 1 = <25 cells, mild reaction; 2 = 25 to 125 cells, moderate reaction; and 3 = >= 125 cells, severe reaction. Fibrous capsule thickness, necrosis, and formation of calcification were recorded. ANOVA and post hoc Dunnett's tests were used for statistically analyses (p<0.05). Results. In terms of oedema, inflammation, fibrous capsule, and necrosis, no significant differences were found in any time period for any material. MTA and Biodentine (R) showed higher calcification than in the ACTIVA BioACTIVE on day 30, and the difference was statistically significant (p<0.05). After 60 days, while calcification was not seen in the control group, it was observed in the test groups. There was a statistically significant difference between the control and the others. Conclusion. All materials were well tolerated by the tissues in the 60-day evaluation period. One notable finding is the presence of dystrophic calcification in the connective tissue adjacent to the newly developed BioACTIVE Base/Liner material. Therefore, this new BioACTIVE Base/Liner material may be safely recommended to clinicians as a pulp capping material.