Methods
Specimens of five printable resins (VarseoSmile Crown plus, NextDent C&B MFH, VarseoSmile Temp, Temp PRINT, P Pro Crown & Bridge), two types of resins for subtractive manufacturing (Tetric CAD, Telio CAD) and two types of resins with conventional curing processes (Tetric EvoCeram, Protemp 4) were produced and finished. Post-processing was strictly performed according to the manufacturer's protocol. Biocompatibility was evaluated by eluting specimens with cell culture medium and treating human gingival fibroblast cells with the eluates. A 72-hour continuous read cell viability assay measuring the reducing potential of the cells was performed. The cellular inflammatory response in terms of IL-6 and PGE2 levels was determined with specific ELISAs. Oxidative stress was determined by measuring oxidized glutathione concentrations after exposure to the resin eluates. A luminescence-based apoptosis assay was used to detect apoptosis.
Results
Tetric CAD and Telio CAD were slightly toxic. All other resins were moderately to severely cytotoxic. VarseoSmile Crown plus and P Pro Crown & Bridge significantly enhanced PGE2 levels. Higher concentrations of oxidized gluthatione were determined in the presence of Telio CAD, VarseoSmile Temp and P Pro Crown & Bridge. Tetric EvoCeram and Protemp 4 reduced intracellular gluthatione levels. All printable resins slightly induced apoptosis. Significance: Further post-processing steps such as additional curing and washing may improve the biocompatibility of printable materials.
Significance
Further post-processing steps such as additional curing and washing may improve the biocompatibility of printable materials.