TY - JOUR
T1 - Cytotoxicity testing of materials with limited in vivo exposure is affected by the duration of cell-material contact
AU - Ciapetti, Gabriela
AU - Granchi, Donatella
AU - Stea, Susanna
AU - Savarino, Lucia
AU - Verri, Elisabetta
AU - Gori, Alessandra
AU - Savioli, Franca
AU - Montanaro, Lucio
PY - 1998/12/15
Y1 - 1998/12/15
N2 - Silicones for dental impression largely are used to record the geometry of hard and soft dental tissues. They are considered to be medical devices, and the assessment of cytotoxicity is a necessary step in the evaluation of their biocompatibility. Extracts of six addition-type and six condensation- type silicones have been tested with L929 cells according to the ISO 10993 - Part 5 standard. The cytotoxicity was evaluated by three different methods: neutral red uptake, propidium iodide (PI) staining, and amido black staining. According to the selected specific assay, contact between cells and material extracts was maintained for 24 h in the first series of experiments; then, considering that in vivo application of these materials is restricted to a few minutes, additional experiments were performed after 1 h of cell/extract contact. Analysis of the results showed that the addition-type silicones are nontoxic even when tested after prolonged exposure of the cells to the materials while the condensation-type silicones were cytotoxic at 24 h of incubation. Nevertheless, harm to the patient actually could be negligible, considering its very short time of exposure in vivo. This is supported by our finding that most are not toxic after 1 h. We suggest that the experimental conditions of cytotoxicity testing have to be relevant to the in vivo situation; accordingly, the time of exposure should be designed carefully.
AB - Silicones for dental impression largely are used to record the geometry of hard and soft dental tissues. They are considered to be medical devices, and the assessment of cytotoxicity is a necessary step in the evaluation of their biocompatibility. Extracts of six addition-type and six condensation- type silicones have been tested with L929 cells according to the ISO 10993 - Part 5 standard. The cytotoxicity was evaluated by three different methods: neutral red uptake, propidium iodide (PI) staining, and amido black staining. According to the selected specific assay, contact between cells and material extracts was maintained for 24 h in the first series of experiments; then, considering that in vivo application of these materials is restricted to a few minutes, additional experiments were performed after 1 h of cell/extract contact. Analysis of the results showed that the addition-type silicones are nontoxic even when tested after prolonged exposure of the cells to the materials while the condensation-type silicones were cytotoxic at 24 h of incubation. Nevertheless, harm to the patient actually could be negligible, considering its very short time of exposure in vivo. This is supported by our finding that most are not toxic after 1 h. We suggest that the experimental conditions of cytotoxicity testing have to be relevant to the in vivo situation; accordingly, the time of exposure should be designed carefully.
KW - Additiontype-silicones
KW - Condensation- type-silicones
KW - Cytotoxicity
KW - Impression materials
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U2 - 10.1002/(SICI)1097-4636(19981215)42:4<485::AID-JBM2>3.0.CO;2-7
DO - 10.1002/(SICI)1097-4636(19981215)42:4<485::AID-JBM2>3.0.CO;2-7
M3 - Article
C2 - 9827670
AN - SCOPUS:0032534526
VL - 42
SP - 485
EP - 490
JO - Journal of Biomedical Materials Research - Part A
JF - Journal of Biomedical Materials Research - Part A
SN - 1549-3296
IS - 4
ER -