Table 1 Summary of studies included in systemic review

(1) Morett et al. [19]

Brazil

2013

-HEMA-free adhesive G-Bond (GC, Tokyo, Japan)

-HEMA-rich Clearfil 3S Bond (Kuraray, Tokyo, Japan)

-composite Gradia Direct

Anterior (GC, Japan)

To evaluate the 3-year clinical performance of two one-step self-etch adhesives, namely one HEMA-free and one HEMA-rich system, in non-carious cervical lesions (NCCL)

Both one-step self-etch adhesives presented an equally favorable clinical effectiveness at 3 years follow-up

(2) van Dijken [23]

Sweden

2013

-HEMA-free 1-step SEA adhesive G-Bond

-hybrid resin composite Gradia Direct posterior (GC, Tokyo, Japan)

-HEMA-containing 2-step SEA adhesive FL-Bond adhesive

-giomer resin composite Beautifil (Shofu, Kyoto, Japan)

To investigate the clinical longevity of class II restorations performed with a HEMA-free1-step SEA adhesive in combination with a micro-fine hybrid resin composite. The restorations were compared intraindividually with Class II HEMA-containing 2-step SEA – giomer restorations

According to the durability in Class II cavities, the HEMA-free adhesive was successful after 6 years. The HEMA-containing SEA-giomer restorations showed rather high failure frequency

(3) van Dijken [23]

Sweden

2013

A single-step, self-etching HEMA-free primer (G-Bond, GC Corp, Tokyo, Japan), a 3-step HEMA/TEGDMA free etch-and-rinse (cfm, Saremco AG, Rebstein, Switzerland) and a 2-step HEMA-containing etch-and-rinse adhesive (XP Bond, Dentsply/DeTrey, Konstanz, Germany) were evaluated in combination with two restorative resinous materials, composite Gradia Direct (GC Corp) was used in combination with G-Bond, and els (extra low shrinkage; Saremco)in combination with the two other adhesives

To determine the long-term clinical bonding durability of a 1-step HEMA-free SEA, a 3-step HEMA/TEGDMA-free etch-and-rinse, and a 3-step HEMA-containing etch-and-rinse adhesive in Class V non-carious cervical lesions without using retention of external lesion surface area

It can be concluded that the durability of non-carious cervical lesions of the HEMA-free adhesives was successful after 5 years. Despite concerns which have been raised, the 1-stepSEA showed one of the best clinical dentin bonding effectiveness

(4)Van Landuyt et al. [9]

2014

1-step SEA G-Bond (GC, Tokyo,

Japan). 3-step E&R Optibond FL (Kerr,

Orange, CA, USA)

Micro-hybrid composite Gradia Direct (GC, Tokyo, Japan)

To determine the long-term clinical performance of a HEMA-free 1-step SEA. This randomized controlled trial was set up to compare the clinical effectiveness of a HEMA-free 1-step SEA with a three-step etchant-rinse adhesive

Restorations bonded with G-Bond did not need clinical intervention more often than those placed with the 3-step E&R Optibond FL and had a high retention rate (> 90%) after 5 years of clinical service. There were, however, differences between both tested adhesives, not decisive for the clinical success rate. The HEMA-free one-step self-etch adhesive exhibited significantly more enamel defects and stains. In the majority of cases, these defects were insignificant, but after 5 years, several restorations also failed because of deep micro leakage

(5) Peumas et al. [20]

Belgium

2018

-HEMA-free 1SEa G-Bond (GB; GC, Tokyo, Japan)

−3E&R Optibond FL (OFL; Kerr, Orange, CA, USA)

-Microhybrid composite (Gradia Direct GC)

To evaluate the 9-year clinical efficacy of the HEMA-free 1SEa G-Bond compared to that

of 3E&Ra Optibond FL

Class-V restorations bonded with the HEMA-free 1SEa performed clinically equally successful as those bonded with the 3E&Ra. However, more marginal deterioration, though still clinically acceptable, was recorded at the incisal enamel side for the 1SEa

(6) Tekce et al. [21]

Turkey

2018

G-aenial Bond (GC Corp, Tokyo, Japan)

-Clearfil S3 Bond (Kuraray.Medical Inc, Tokyo, Japan)

-Fortify Plus Filled Surface Sealant (Bisco, Schaumburg, IL, USA)

-Clearfil Majesty Posterior Kuraray Medical Inc, Tokyo, Japan)

To evaluate the clinical performance

of HEMA-containing and HEMA-free all-in-one self-etch adhesives with and without a surface sealing process in Class I cavities

None of the restorations failed after 2 years, and

there were no significant differences between the

clinical performance of HEMA-containing and HEMA-free all-in-one self-etch adhesives with and without surface sealing in Class I restorations over the same time period

(7) Oliveira et al. [22]

Brazil

2023

-Prime & Bond U (Dentsply Sirona, Konstanz, Germany)

-Optibond All-in-One (Kerr, New South Wales, Australia)

-Clearfil SE (Kuraray Medical Inc., Tokyo, Japan)

-Filtek Z350 XT Color A3 composite resin (3 M ESPE, Sumar´e, SP, Brazil)

To evaluate the clinical performance of a self-etching adhesive system associating the functional monomers HEMA and 10-MDP in the restoration of NCCLs over 2 years

The association of HEMA and 10-MDP monomers in the self-etching adhesives did not influence the Clinical performance of the NCCL restorations with respect to retention, post-operative sensitivity, and incidence of secondary caries. However, positively influenced the marginal adaptation and marginal staining at the 2-year follow-up