IADR Abstract Archives
Influence of Various Irradiation-processes on the Mechanical-properties of Nano-hybrid Composites
Objectives: To evaluate the influence of irradiation time and regimes on the mechanical properties of nano-hybrid composites at simulated clinically relevant curing distances.
Methods: Two nano-hybrid resin-based composites (Kalore, GC and Filtek™Supreme XTE, 3M/ESPE) were investigated by assessing the variation in micromechanical properties (Vickers hardness-HV and indentation modulus-E) within simulated 2-mm deep fillings (n=6) polymerized with a violet-blue LED curing unit (Bluephase 20i, Ivoclar Vivadent) under 8 different curing conditions. The exposure duration was 10 and 20s in the high power mode; 5 and 10s in the turbo mode; the exposure distance was 0 and 7-mm. Energy density ranged from 5.81 to 15.33 J/cm2. Measurements were performed after 24h of storage in distilled water at 37°C.. Curing unit’s irradiance was monitored in 1-mm steps at distances up to 10 mm away from the light tip on a laboratory-grade spectrometer. Statistical analyzes were done using t-test and Tukey HDS tests (p<0.05). The results were compared using a multivariate analysis (general linear model, α=0.05) assessed the effect of the parameters material, curing mode and distance away from the curing unit tip on the considered properties.
Results: The energy density at the bottom of the specimens was larger in Kalore (ranging from 0.55 to 2.21 J/cm2) compared with Filtek Supreme XTE (0.14-0.61 J/cm2). The parameters (distance from the light tip and depth) emphasize a stronger influence on mechanical properties of Filtek Supreme XTE. Distance away from the light tip did not influence the mechanical properties of Kalore. The bottom/top hardness for Filtek Supreme XTE was below 80% in all regimes.
Conclusions: The nano-hybrid composites react differently to the analyzed curing regimes, depending on their structure and composition. An increase in bottom/top hardness with increased energy density was observed in all materials, Kalore showed higher bottom/top hardness values than Filtek Supreme XTE at given curing conditions.
Methods: Two nano-hybrid resin-based composites (Kalore, GC and Filtek™Supreme XTE, 3M/ESPE) were investigated by assessing the variation in micromechanical properties (Vickers hardness-HV and indentation modulus-E) within simulated 2-mm deep fillings (n=6) polymerized with a violet-blue LED curing unit (Bluephase 20i, Ivoclar Vivadent) under 8 different curing conditions. The exposure duration was 10 and 20s in the high power mode; 5 and 10s in the turbo mode; the exposure distance was 0 and 7-mm. Energy density ranged from 5.81 to 15.33 J/cm2. Measurements were performed after 24h of storage in distilled water at 37°C.. Curing unit’s irradiance was monitored in 1-mm steps at distances up to 10 mm away from the light tip on a laboratory-grade spectrometer. Statistical analyzes were done using t-test and Tukey HDS tests (p<0.05). The results were compared using a multivariate analysis (general linear model, α=0.05) assessed the effect of the parameters material, curing mode and distance away from the curing unit tip on the considered properties.
Results: The energy density at the bottom of the specimens was larger in Kalore (ranging from 0.55 to 2.21 J/cm2) compared with Filtek Supreme XTE (0.14-0.61 J/cm2). The parameters (distance from the light tip and depth) emphasize a stronger influence on mechanical properties of Filtek Supreme XTE. Distance away from the light tip did not influence the mechanical properties of Kalore. The bottom/top hardness for Filtek Supreme XTE was below 80% in all regimes.
Conclusions: The nano-hybrid composites react differently to the analyzed curing regimes, depending on their structure and composition. An increase in bottom/top hardness with increased energy density was observed in all materials, Kalore showed higher bottom/top hardness values than Filtek Supreme XTE at given curing conditions.