IADR Abstract Archives
Resin Bond Strength to Unprepared, Minimally Prepared and Air-Abraded Enamel
Objectives: The purpose of this study was to investigate the resin bond strength to unprepared, minimally invasive prepared and air-abraded enamel using an axial tensile bond strength (TBS) test. In addition, the influence of a non-application of phosphoric acid and sole application of a self-etching primer on the bond strength was evaluated.
Methods: Caries and filling-free human wisdom teeth were centered with the proximal surfaces and embedded perpendicular to cylinder axis with composite resin (Luxatemp-Star) in brass rings. Plexiglas tubes (inner diameter 3.2 mm) filled with composite resin (Clearfil FII) were axially bonded with luting resin (Panavia V5). The specimens were randomly distributed, according to the surface treatment protocol, into 3 groups (n=16): no enamel preparation, but cleaning with sodium bicarbonate powder (SBP) spray (N), minimally invasive enamel preparation with fine-grained diamond burs and cleaning with SBP spray (M), air-abrasion with 85 µm Al2O3 (Orthoprophy SA-85, 20s, 0.25 MPa) (O). Each group was then tested under two conditions (n=8). Enamel was conditioned with either 35% phosphoric acid followed by application of a self-etching primer (Tooth Primer) (PT) or application of the primer only (T). The specimens were stored in water (37°C) for 3 d. TBS was evaluated using a universal testing machine (Zwick Z010) with a crosshead speed of 2 mm/min. Data were statistically analyzed using Two-way ANOVA, followed by Tukey’s post-hoc.
Results: The mean TBS ranged from a minimum 16.4±5.5 MPa (OT) to a maximum of 32.0±8.8 MPa (MPT). Enamel preparation had no significant effect on TBS, while the application of phosphoric acid led to a statistically significant higher TBS.
Conclusions: Regardless of the pretreatment of enamel, the groups with phosphoric acid etching showed comparably higher TBS than the sole application of a self-etching primer.
Methods: Caries and filling-free human wisdom teeth were centered with the proximal surfaces and embedded perpendicular to cylinder axis with composite resin (Luxatemp-Star) in brass rings. Plexiglas tubes (inner diameter 3.2 mm) filled with composite resin (Clearfil FII) were axially bonded with luting resin (Panavia V5). The specimens were randomly distributed, according to the surface treatment protocol, into 3 groups (n=16): no enamel preparation, but cleaning with sodium bicarbonate powder (SBP) spray (N), minimally invasive enamel preparation with fine-grained diamond burs and cleaning with SBP spray (M), air-abrasion with 85 µm Al2O3 (Orthoprophy SA-85, 20s, 0.25 MPa) (O). Each group was then tested under two conditions (n=8). Enamel was conditioned with either 35% phosphoric acid followed by application of a self-etching primer (Tooth Primer) (PT) or application of the primer only (T). The specimens were stored in water (37°C) for 3 d. TBS was evaluated using a universal testing machine (Zwick Z010) with a crosshead speed of 2 mm/min. Data were statistically analyzed using Two-way ANOVA, followed by Tukey’s post-hoc.
Results: The mean TBS ranged from a minimum 16.4±5.5 MPa (OT) to a maximum of 32.0±8.8 MPa (MPT). Enamel preparation had no significant effect on TBS, while the application of phosphoric acid led to a statistically significant higher TBS.
Conclusions: Regardless of the pretreatment of enamel, the groups with phosphoric acid etching showed comparably higher TBS than the sole application of a self-etching primer.