IADR Abstract Archives
Apatite promoting, high strength propylene based dental composite with better cytocompatibility and subsequent high antibacterial release
Objectives: Assess the effect of varying levels of strontium fillers on degree of conversion, flexural strength, adhesion, biofilm and cytocompatibility of propylene based dental composites
Methods: Light curable dental monomers were prepared by mixing BisGMA, polypropylene-dimethacrylate, camphorquinone and n-n-dimethyl-p-toluidine. Silane-treated-glass-particles along with varying levels of reactive strontium and calcium fillers (0,10,20 and 40% of filler phase) were added to the above monomer mixture. Z250™ was used as a commercial control. Monomer conversion and depth of cure after 20s light cure was assessed through FTIR. Shear bond strength was measured using ivory dentine following ISO 29022:2013. Instron testing machine was used for evaluating the biaxial flexural strength in simulated body fluid (SBF) after 1 day and 30days.Strontium release in SBF was measured using inductively-coupled-plasma-mass-spectrometry. Antibacterial activity was assessed using a biofilm model. MTS Assay was used to assess the cytocompatibility (ISO 10993-12:2012). Bioactivity was assessed in SBF for 28 days using ISO 23317:2014
Results: All experimental formulations showed higher degree of monomer conversion, toughness and shear bond strength, compared to Z250™(Tab1). Addition of strontium phosphate decreased the biaxial flexural strength and depth of cure, however, there was no effect on monomer conversion at 1 mm(Fig1a). Strontium release was proportional to the square root of time (hrs) and its loading level (p<0.01)(Fig1b). Strontium phosphate fillers had no significant effect on bacteria growth in suspension, however, bacterial attachment on discs decreased significantly(p<0.01)(Fig2a). Cell viability significantly increased with the addition of reactive strontium phosphate at indicated time points (p<0.01)(Fig2b). Apatite layer was only formed on S20 and S40 (Fig3)
Conclusions: Strontium phosphate based dental composite showed promising mechanical, adhesive and antibacterial properties. These materials could potentially solve the problem of future micro-leakage and sub surface caries as well as promote remineralisation of the demineralized dentine
Methods: Light curable dental monomers were prepared by mixing BisGMA, polypropylene-dimethacrylate, camphorquinone and n-n-dimethyl-p-toluidine. Silane-treated-glass-particles along with varying levels of reactive strontium and calcium fillers (0,10,20 and 40% of filler phase) were added to the above monomer mixture. Z250™ was used as a commercial control. Monomer conversion and depth of cure after 20s light cure was assessed through FTIR. Shear bond strength was measured using ivory dentine following ISO 29022:2013. Instron testing machine was used for evaluating the biaxial flexural strength in simulated body fluid (SBF) after 1 day and 30days.Strontium release in SBF was measured using inductively-coupled-plasma-mass-spectrometry. Antibacterial activity was assessed using a biofilm model. MTS Assay was used to assess the cytocompatibility (ISO 10993-12:2012). Bioactivity was assessed in SBF for 28 days using ISO 23317:2014
Results: All experimental formulations showed higher degree of monomer conversion, toughness and shear bond strength, compared to Z250™(Tab1). Addition of strontium phosphate decreased the biaxial flexural strength and depth of cure, however, there was no effect on monomer conversion at 1 mm(Fig1a). Strontium release was proportional to the square root of time (hrs) and its loading level (p<0.01)(Fig1b). Strontium phosphate fillers had no significant effect on bacteria growth in suspension, however, bacterial attachment on discs decreased significantly(p<0.01)(Fig2a). Cell viability significantly increased with the addition of reactive strontium phosphate at indicated time points (p<0.01)(Fig2b). Apatite layer was only formed on S20 and S40 (Fig3)
Conclusions: Strontium phosphate based dental composite showed promising mechanical, adhesive and antibacterial properties. These materials could potentially solve the problem of future micro-leakage and sub surface caries as well as promote remineralisation of the demineralized dentine
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