The objective of the study was the testing of cytotoxicity (= cell toxicity) of 3D-printed restorations made of VarseoSmile Crown plus in accordance with DIN EN ISO 10993-5, which is fundamentally intended for the determination of the biocompatibility of materials.
For this test, extracts of the pertinent samples, which were produced as per manufacturer specifications, were compared with the pure dissolver (solvent) and with positive and negative control samples.
To prepare the extracts, the test specimens were extracted in a solvent for 24 hours. These extractswere then diluted to obtain four different concentrations (100% (undiluted), 66.7%, 44.4%, 29.6%).
In order to ensure the validity of the test, the pure solvent (without contact to the test specimens) as well as one negative (polypropylene) and one positive sample (latex) were also tested. The pure solvent was used as reference. For the negative probe, a substance that in accordance with DIN EN ISO 10993-5 demonstrates no evidence of cytotoxicity was used. In contrast to this, a cytotoxic material was used for the positive probe.
The extracts of the control samples and the different extract concentrations of the test specimens were added to cell cultures and after 68 h to 72 h the cell activity, which is determined through enzymatic reactions, was measured. The activity of mitochondrial dehydrogenases (an enzyme) was measured as a gage of cell activity. Certain “markers”, i.e. substances that react to certain enzymes and form colored complexes, were used for detection purposes. Cell activity was determined through color intensity and the XTT method (XTT = sodium-3‘-[-(1-phenylamino carbonyl)-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzenesulfonic acid hydrate) was applied as standard. With cell activity falling below 70%, the test is considered as not passed. The closer the cell activity is to that of the solvent control, the better.
The results of VarseoSmile Crown plus in the XTT test yielded, for all tested concentrations, including for the undiluted extract (100%), cell activities (determined through mitochondrial dehydrogenase activity) that were markedly higher than 70%. Thus, the test is considered as passed.
VarseoSmile Crown plus showed no cytotoxic properties in the XTT test. Thus, the results of the extraction measurement are confirmed. VarseoSmile Crown plus therefore constitutes a very well tolerated material.
Mitochondrial dehydrogenase activity of VarseoSmile Crown plus and of the dissolver (solvent), negative and positive samples in the XTT test, results for test specimens that were polymerized with either the Otoflash G171 or Hilite Power light-curing devices
The above information is based on a scientific study of the cytotoxicity of VarseoSmile Crown plus, conducted by:
Eurofins BioPharma Product Testing Munich GmbH, Germany
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