Table 1.

Summary of included studies.

	Pacifici et al. 2013 [38]	Scaminaci Russo et al. 2013 [39]	Poorzandpoush et al. 2019 [40]
Aim of the study	To evaluate SBS to dentin of primary molars of SFC, GIC, RMGIC, and CF in combination with two different adhesive systems.	To compare µSBS to human primary dentin of SFC, self-etch adhesive + CF, and GIC.	To compare SBS of SFC, CF, and RMGIC to primary dentin.
Type of SFC	Vertise Flow (Kerr, Orange, CA, USA).	Vertise Flow (Kerr, Orange, CA, USA).	Vertise Flow (Kerr, Orange, CA, USA).
Type of GIC or RMGIC	Fuji II LC Capsule (GC Corp., Tokyo, Japan); Fuji IX GP Fast Capsule (GC Corp., Tokyo, Japan).	Ketac Fil (EMS, Milano, Italy)	Ionolux® (VOCO Dental, GmbH, Cuxhaven, Germany).
Group Distribution and Intervention	G1 (n = 10): Total-etch adhesion + CF; G2 (n = 10): Self-etch adhesion + CF; G3 (n = 10): Polyacrylic Acid + GIC; G4 (n = 10): Polyacrylic Acid + RMGIC; G5 (n = 10): SFC (no surface pre-treatment).   SBS test: After restoration, samples were positioned in a universal testing machine. Load was parallel to the bonded interface at a crosshead speed of 1 mm/min until failure.	G1 (n = 25): SFC (no surface pre-treatment); G2 (n = 25): Self-etch adhesion + CF; G3 (n = 25): polyacrylic acid+ GIC.   SBS test: After restoration, samples were stored in water in a light-proof container at 37 °C for 24 h and then thermocycled for 1500 cycles between 5 and 55 °C. Then, specimens were positioned in a universal testing machine. Load was applied to the resin/dentin interface at a crosshead speed of 1 mm/min until failure.	G1 (n = 16): GIC (no surface pre-treatment); G2 (n = 16): Total-etch adhesion + CF; G3 (n = 16): SFC (no surface pre-treatment).   SBS test: After restorations, samples were thermocycled for 1000 cycles between 5 and 55 °C. Using a universal testing machine, load was applied perpendicular to the tooth-restoration interface at a crosshead speed of 1 mm/min and until bond failure.
Evaluated outcomes	SBS (Mpa) + mode of failure (adhesive; cohesive or mixed).	µSBS (Mpa) + mode of failure (adhesive; cohesive dentin failure; cohesive build-up failure; mixed with 1 and 2 and mixed failure with 1 and 3.	SBS (Mpa) + mode of failure (adhesive; cohesive or mixed).
Results	SBS: G1 > G2 > G4 > G3 > G5 G1 showed significantly higher SBS values than all the other tested materials. SBS achieved by G5 was statistically comparable to G3 and G4. Mode of failure: Cohesive failures within dentin only in G1 and G2. Adhesive failures in G3, G4, and G5. Statistically significant differences between G1/G2 and G3/G4/G5.	SBS: G2 > G1 > G3 Differences were statistically significant. Mode of failure: mostly adhesive in all groups. The differences in failure mode distribution were statistically significant (p < 0.001). G3 exhibited a significantly greater number of mixed failures (adhesive/cohesive in build-up) and cohesive in build-up than G1 and G2. No statistically significant difference between Groups 1 and 2.	SBS: G2 > G3 > G1 G2 had a significantly higher SBS than G1 and G3 (p < 0.001). No significant differences between G3 and G1. Mode of failure: adhesive type was the most frequent in G2 and G3. Adhesive failure was noted in 100% of samples of G1.
Conclusions	SFC achieved SBS values comparable to those of GIC-based restorative materials routinely used to restore primary teeth.	SFC may be a reliable option to conventional materials used for the restoration of deciduous teeth especially in young or noncompliant children.	CF yielded the highest SBS to primary dentin. SFC and RMGIC demonstrated the lowest SBS with no significant difference with each other.

CF: conventional flowable composite. GIC: glass-ionomer cement. RMGIC: resin-modified glass-ionomer cement. SBS: shear bond strength. SFC: self-adhesive flowable composite.