Cytotoxicity of a Silorane-Based Composite in a Dentin Barrier Test

The biocompatibility is an important requirement for a dental filling material. Objective: To evaluate the cytotoxicity of a new silorane-based resin composite material with its corresponding adhesive in comparison with a known material in a dentin barrier test simulating the in vivo situation. Methods: Three dimensional cultures of SV40 transfected pulp derived Cells (Thonemann and Schmalz, Arch Oral Biol, 45, 857-869, 2000) were transferred into an in vitro dentin barrier test device with dentin slices of 200 and 500 mm thickness. After 24 h incubation at 37°C the test materials were applied into the cavity part of the device: Hermes Composite with its corresponding adhesive (3M ESPE) and Tetric Ceram/Exite (Ivoclar-Vivadent). A light curing glass ionomer cement (Vitrebond, 3M ESPE) was used as reference material and an A-silicone impression material (President, Coltene) as negative control (100% cell vitality).The pulpal part of the device was perfused with cell culture medium. After 24 h exposure, cell survival was measured by MTT test and 15 cultures per material were statistically analyzed (Mann-Whitney-test, α=0.05). Results: With 500 mm dentin, cell survival rates for Hermes System (96%) and Tetric Ceram/Exite (98%) were statistically not different from the negative control, but from the reference material (75%). With 200 mm dentin, cytotoxicity of test materials was not changed. However, the glass ionomer cement showed higher cytotoxicity when dentin slices with 200 mm thickness were use (44%). Conclusion: With residual dentin barriers of 200 mm and 500 mm the tested silorane-based composite/adhesive may not alter biologically the dental pulp on a short term basis.