IADR Abstract Archives
Bonding Effectiveness of Universal Adhesive not Affected by air-Abrasion/Polishing Dentin
Objectives: To evaluate the effect of air-abrasion/polishing on micro-tensile bond strength (µTBS) to dentin.
Methods: Third molars had their occlusal third cut and dentin surface divided into two parts. Smear layer was prepared using a medium-grit diamond bur (107 µm). Dentin was air-abraded/polished under distilled water irrigation at 4 bar for 15 sec (Aquacare, Velopex) using 6 Velopex powders (n=10; no air-abrasion/polishing as control): aluminum oxide 29 µm (AO_29) and 53 µm (AO_53), sodium bicarbonate (SB), sodium bicarbonate soft (SB_soft), bioactive glass (BG), and aluminum trihydroxide (AT). G2-Bond Universal (‘G2B’; GC) was applied according to the manufacturer’s instructions. Using a split-tooth model, the adhesive was applied in etch-and-rinse (E&R) bonding mode at one dentin-surface half, and in self-etch (SE) mode at the other half. A composite build-up (Clearfil AP-X; Kuraray Noritake) of 5-mm height was made in 3 layers. After one-week water storage (37°C), teeth were cut using a low-speed diamond saw in micro(µ)-specimens. Half of the µ-specimens were ‘immediately’ tested, with the other half first subjected to 50k thermocycles. The failure mode of all specimens was determined by light-microscopy (‘adhesive interfacial failure’, ‘cohesive failure in dentin’ or ‘mixed failure’), followed by SEM fracture analysis of selected specimens. Data were analyzed using 2-way ANOVA and Tukey (α=0.05).
Results: No significant difference in µTBS was recorded between the air-abrasion/polishing methods and control, this when G2B was bonded in both E&R and SE mode (Figure). In all groups, the E&R bonding mode resulted in higher µTBS than the SE mode, although being only statistically significant for AO_29 and SB when measured immediately and upon aging, and for SB_soft upon aging.
Conclusions: Overall, air-abrasion/polishing with any powder did neither impair nor improve µTBS to dentin. Upon aging, G2B bonded more effectively in E&R mode than in SE mode for some specific air-abrasion/polishing methods.
Methods: Third molars had their occlusal third cut and dentin surface divided into two parts. Smear layer was prepared using a medium-grit diamond bur (107 µm). Dentin was air-abraded/polished under distilled water irrigation at 4 bar for 15 sec (Aquacare, Velopex) using 6 Velopex powders (n=10; no air-abrasion/polishing as control): aluminum oxide 29 µm (AO_29) and 53 µm (AO_53), sodium bicarbonate (SB), sodium bicarbonate soft (SB_soft), bioactive glass (BG), and aluminum trihydroxide (AT). G2-Bond Universal (‘G2B’; GC) was applied according to the manufacturer’s instructions. Using a split-tooth model, the adhesive was applied in etch-and-rinse (E&R) bonding mode at one dentin-surface half, and in self-etch (SE) mode at the other half. A composite build-up (Clearfil AP-X; Kuraray Noritake) of 5-mm height was made in 3 layers. After one-week water storage (37°C), teeth were cut using a low-speed diamond saw in micro(µ)-specimens. Half of the µ-specimens were ‘immediately’ tested, with the other half first subjected to 50k thermocycles. The failure mode of all specimens was determined by light-microscopy (‘adhesive interfacial failure’, ‘cohesive failure in dentin’ or ‘mixed failure’), followed by SEM fracture analysis of selected specimens. Data were analyzed using 2-way ANOVA and Tukey (α=0.05).
Results: No significant difference in µTBS was recorded between the air-abrasion/polishing methods and control, this when G2B was bonded in both E&R and SE mode (Figure). In all groups, the E&R bonding mode resulted in higher µTBS than the SE mode, although being only statistically significant for AO_29 and SB when measured immediately and upon aging, and for SB_soft upon aging.
Conclusions: Overall, air-abrasion/polishing with any powder did neither impair nor improve µTBS to dentin. Upon aging, G2B bonded more effectively in E&R mode than in SE mode for some specific air-abrasion/polishing methods.
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