Clearfil majesty es flow

Four nanofilled flowable resin composites of A3 shade were used in this study; Filtek Supreme Ultra Flowable Restorative (FSU; 3M, St. Paul, MN, USA), Estelite Flow Quick (EFQ; Tokuyama Dental, Tokyo, Japan), Estelite Universal Flow, (EUF; Tokuyama Dental), and Clearfil Majesty ES Flow (ESF; Kuraray Noritake Dental, Tokyo, Japan). Their composition is listed in Table 1.

Each tube was filled with flowable nanofilled composite resin (Clearfil Majesty ES Flow, Kuraray) and then light-cured for 40 s with the tip of the light guide in contact with the top of the tube. A single operator performed all adhesive procedures. The specimens were then immersed in distilled water at 37 °C for 24 h. Before testing, the tube was sectioned and carefully removed to leave a composite rod perpendicular to the tooth surface (Figure 2). The specimens were positioned in a jig attached to a universal testing machine (Acquati, Milan, Italy). A stainless steel wire loop (0.2 mm diameter) was placed against the enamel surface, engaging the lower half-circle of one cylinder per time. A shear load was applied at a crosshead speed of 1.0 mm/min until failure occurred. Care was taken to keep the composite cylinder in line with the centre of the load cell. The wire loop was kept parallel to the adhesive interface as well as to the movement direction of the load cell. The maximum load at failure was recorded for each specimen in Newtons (N). The shear bond strength (SBS) was calculated by dividing the maximum load (N) by the bonding surface (mm 2 ) and expressed in Mega Pascals (MPa).

The resin-coating materials used in this study are presented in Table 1. The materials were applied to the entire cavity surface, including the enamel margins. Any excess material was removed prior to light-curing with a light-emitting diode (LED) light-curing unit (VALO, Ultradent, South Jordan, UT, USA) used in "standard mode" (1,000 mW/cm 2 ). The specimens were randomly distributed into 3 groups according to the surface of the cavity treatment as follows.
Uncoated group: The surface of the cavity was left uncoated as a control.
1-step group: A one-bottle adhesive system, G-Premio Bond (G-Premio) (GC, Tokyo, Japan), was used as a resin-coating material. G-Premio was applied to the surface of the cavity, immediately subjected to strong air-drying, and then light-cured for 10 s.
2-step+Flow group: A combination of a two-step self-etch adhesive, Clearfil SE Bond 2 (SE2) (Kuraray Noritake Dental, Tokyo, Japan) and a flowable resin composite, Clearfil Majesty ES Flow (ES flow) (Kuraray Noritake Dental), was used as resin-coating materials. The primer of SE2 was applied for 20 s and air-dried. Then, the bonding agent of SE2 was applied, gently airdried, and light-cured for 10 s. Afterward, ES flow was thinly placed on the cavity with a disposable applicator brush and light-cured for 20 s.