IADR Abstract Archives
Effect of Simulated Pulp- Pressure on Bond Strength of Universal Adhesive
Objectives: Several universal adhesive systems have been recently marketed. Screening studies are crucial for characterizing their bonding performance under clinically relevant situations compared to reference materials. This study evaluated the effect of simulated pulpal pressure on the microtensile bond strength (µTBS) of universal adhesive systems to dentin compared to a two-step self-etch adhesive.
Methods: Twenty-four sound human molars were sectioned to exposed flat dentin surfaces and randomly divided into four groups according to the adhesive systems: two-step self-etch adhesives - Clearfil Mega Bond 2 (MB2, Kuraray Inc.) and G2-Bond (G2B, GC Corp.), universal adhesives - Scotchbond Universal Plus (SBP, 3M Oral Care) and Beautibond Xtreme Universal (BX, Shofu Inc.). Each adhesive group was further divided (n=3) following the pulp pressure simulation (non-simulated – No-SPP; simulation with distilled water – Dw-SPP). Resin composite build-ups were made, and teeth were stored in water (37°C, 24 h). Teeth were sectioned in both directions to obtain 1mm2 sticks and tested under tension to determine the µTBS. Data (in MPa) were statistically analyzed using two-way ANOVA and Tukey HSD tests (α=0.05). Failure mode was observed using a stereomicrocospe and SEM.
Results: The bond strength to dentin was significantly affected by materials (p<0.001), pulp pressure simulation (p<0.001) and their interaction (p=0.002). MB2/No-SPP (59.79±7.70MPa) showed the highest µTBS and G2B/Dw-SPP presented the lowest value (15.41±4.45MPa). Simulated pulp pressure significantly decreased the bond strength of all materials to dentin. The failure mode was predominantly mixed for all materials and experimental conditions.
Conclusions: Clearfil Mega Bond 2, a two-step etch-adhesive, presented the best bonding performance regardless of the pulp pressure simulation. The simulation of pulp pressure using distilled harmed the bonding performance of all adhesive systems.
Methods: Twenty-four sound human molars were sectioned to exposed flat dentin surfaces and randomly divided into four groups according to the adhesive systems: two-step self-etch adhesives - Clearfil Mega Bond 2 (MB2, Kuraray Inc.) and G2-Bond (G2B, GC Corp.), universal adhesives - Scotchbond Universal Plus (SBP, 3M Oral Care) and Beautibond Xtreme Universal (BX, Shofu Inc.). Each adhesive group was further divided (n=3) following the pulp pressure simulation (non-simulated – No-SPP; simulation with distilled water – Dw-SPP). Resin composite build-ups were made, and teeth were stored in water (37°C, 24 h). Teeth were sectioned in both directions to obtain 1mm2 sticks and tested under tension to determine the µTBS. Data (in MPa) were statistically analyzed using two-way ANOVA and Tukey HSD tests (α=0.05). Failure mode was observed using a stereomicrocospe and SEM.
Results: The bond strength to dentin was significantly affected by materials (p<0.001), pulp pressure simulation (p<0.001) and their interaction (p=0.002). MB2/No-SPP (59.79±7.70MPa) showed the highest µTBS and G2B/Dw-SPP presented the lowest value (15.41±4.45MPa). Simulated pulp pressure significantly decreased the bond strength of all materials to dentin. The failure mode was predominantly mixed for all materials and experimental conditions.
Conclusions: Clearfil Mega Bond 2, a two-step etch-adhesive, presented the best bonding performance regardless of the pulp pressure simulation. The simulation of pulp pressure using distilled harmed the bonding performance of all adhesive systems.