The development of self-adhesive resin cements containing SR-bioactive glass and calcium phosphate

Objectives: The lack of remineralizing effect of self-adhesive resin cement could lead to the increase of secondary caries at the tooth-restoration interface in high-caries risk patients. The aim of this study was to develop novel self-adhesive resin cement containing Sr-containing bioactive glass nanoparticles (Sr-BGNPs) and monocalcium phosphate monohydrate (MCPM). The effect of rising Sr-BGNPs and MCPM concentrations on the degree of monomer conversion (DC), biaxial flexural strength/modulus (BFS/BFM), shear bond strength to Lithium Disilicate (SBS to LDS), mass/volume changes, color stability, and ions release of the experimental resin cements were investigatedMaterials and methods: The liquid phase contained dimethacrylate monomers with adhesive monomer. The powder phase contained boroaluminosilicate glass incorporated with Sr-BGNPs (5 or 10wt%) and MCPM (3 or 6wt%). DC was evaluated using FTIR-ATR (n=5). BFS/BFM after water immersion for 24 h and 4 weeks were examined using a universal testing machine (n=7). SBS to LDS was tested with universal testing machine (n=6). The mode of failure after the SBS test was investigated with a stereomicroscope and SEM-EDX. Mass/volume changes of material after immersion for 4 weeks were measured using a gravimetric study (n=5). Color stability after immersion in water for 24 h and 4 weeks was measured using a dental spectrophotometer (n=5). The release of Ca, P and Sr ions at 24 h, 2, and 4 weeks was analyzed with ICP-OES (n=3). The commercial self-adhesive resin cement (Panavia SA plus, PV) was used as the comparison.Results: The additives showed no effect on DC, shear bond strength to LDS, and volume change of experimental self-adhesive resin cement. MCPM reduced biaxial flexural strength (15±9%) and biaxial modulus (19±5%) of experimental self-adhesive resin cements, but the values were in the acceptable range. MCPM increased mass change (35 ±18%) and color difference (24 ±14%) of experimental self-adhesive resin cements. The additives (Sr-BGNPs and MCPM) enhanced the release of Ca, P, and Sr of experimental resin cements.Conclusions: the experimental materials showed acceptable mechanical properties with ion-releasing properties which could promote remineralization. The ability of remineralization of this experimental resin cement should be assessed in further studies.