The aim of this article is to evaluate the biocompatibility of materials used in pulp capping procedures, by measuring the degree of inflammation induced by these products after subcutaneous implantation in rats. We used 12 animals divided in 3 study groups and 1 control group; implants with Mineral Trioxide Aggregate (MTA), Life cement and Calxyd were placed in subcutaneous tissue and histological evaluation was carried out after 7, 14 and 21 days. We obtained comparable results between MTA and Life cement, which demonstrates similar degrees of biocompatibility. Due to excellent long-term clinical results, the replacement of calcium hydroxide containing materials with MTA is not necessary. Further clinical studies are needed to evaluate the potential of MTA to induce dentin bridge formation on exposed dental pulp.