Hypothesis: Different light-cured bonding agents may have different cytotoxic effects depending on their chemistry.
Objective: Compare and analyze the toxicity of three different light-cured bonding agents to a population of gingival cells as measured by cell growth, and viability in vitro.
Method: Light Bond®, MonoLok®, and Transbond XT® orthodontic adhesives were tested. Human gingival cells were obtained from extracted third molars, pooled, and expanded until needed. Cells were seeded in a 24-well plate at 5 x 104 cells/well over plastic tissue culture treated coverslips containing bonded brackets and incubated for 48 hours. For histological evaluation, cells were stained with 0.2% Toluidine Blue for 2 min. Cells were photographed using light microscopy. Cell viability/cytotoxicity assay was performed with 4µM EthD-1 and 2 µM calcein AM for 45 min. at 37°C and photographed using fluorescence microscopy. 2 x 105 cells/well were seeded with brackets and counted for three days to establish cell growth curve compared to a non-bonded control.
Result: Toluidine blue stained cultures indicated sparse cell attachment close to MonoLok® and Light Bond® resins. Whereas Transbond XT® showed increased biocompatibility. These results were confirmed by cell viability/cytotoxicity assay as well as cell growth which showed a 1.5 fold increase between between 24 and 48 hours.
Conclusion: This data indicates the potential biocompatibility of Transbond XT® as compared to MonoLok® and Light Bond® and warrants further research.
Keywords: Biocompatibility, Fibroblasts and Orthodontics
See more of: Dental Materials 5: Biocompatibility and Biologic Effects