O objetivo do presente trabalho foi avaliar, de maneira preliminar, a capacidade dos fibroblastos L929 sobreviver e se multiplicar quando cultivados sobre discos de den tina humana condicionados com agentes ácidos. Para isso, 10.000 células/cm2 foram cultivadas por 24 ou 48 horas sobre discos de dentina previamente condicionados com ácido cítrico 50% por 30 segundos, com EDTA 0,5 M por 120 segundos (Grupos Experimentais) ou sobre substrato plástico (Grupos Controle). Decorridos os períodos experimentais, as células foram tratadas com fluorescein diacetate (FDA) e finalmente contadas em microscopia de Contraste de Fase. A morfologia celular foi avaliada em microscopia eletrônica de varredura (MEV). Fibroblastos L 929 sobreviveram, multiplicaram-se e apresentaram semelhante morfologia quando cultivados em ambos os substratos avaliados. Os discos de dentina tratados com ácido cítrico exibiam maior número de células do que para os demais grupos Experimentais e Controle, sendo esta observação comprovada pela análise estatística de ANOVA e a complementar de Fisher.

An in vitro pulp device (IVPD) has been developed to carry out in vitro studies concerning the cytotoxic effects of dental materials. This IVPD has allowed that different cell lines can be plated on pulpal surface of dentin discs rather than on the bot tom of its pulpal compartment. Consequently, the aim of this preliminary study was to evaluate the conditions in which a fibroblast cell line (L 929) can grow on human dentin discs previously conditioned with different acidic agents. This is in order to determine whether a reproducible cell number can be maintained on dentinal substrate. In this way, 10.000 cells/cm2 were allowed growing for 24 or 48 hours on plastic (Control Group) or dentin discs conditioned with either 50% citric acid - 30 seconds or EDTA 0.5M- 120 seconds (Experimental Groups). Following application of fluorescein diacetate (FDA) on the cells, they were counted under Phase Contrast Microscope. Cell morphology was assessed by SEM. It was observed that L 929 fibroblasts were able to survive and multiply on human dentin discs as well as on plas tic. The cells showed similar morphology for either substrate. Therefore, the dentin discs treated with 50% citric acid showed higher number of cells on their surfaces than dentin discs treated with EDTA or plated on plastic substrate (Control Groups) for both time of evaluation. It was confirmed by ANOVA and Fisher’s PLSD statistical analysis