Clinical and radiographic evaluation of conventional glass ionomer cement, flowable resin reinforced glass ionomer cement and self-adhesive fluoride releasing composite restorations in primary molars: a comparative randomized clinical trial

Dental caries is a multifactorial, dynamic, diet-modulated, biofilm-mediated disease that causes a net mineral loss in the tooth hard tissues. It is regarded as a serious public health issue and is the most prevalent noncommunicable disease in the world. Approximately 530 million children worldwide suffer from caries in their primary teeth, compared to an estimated 2.3 billion adults with caries in their permanent teeth. Caries management in children requires careful selection of restorative material with restorations lasting until teeth exfoliates. While for decades amalgam has been preferred due to moisture tolerance, ease of placement, and low cost. However, its use has been declined due to poor aesthetics and detrimental health effects caused by mercury release. However, Glass ionomer cement (GIC) is the most commonly used amalgam substitute. As it has the advantages of chemically adhesion to tooth structure, highly biocompatible and releases fluoride over time to provide a cariostatic effect. On the other hand, it has poor wear resistance, a slow setting rate, low fracture toughness, susceptibility to moisture contamination and dehydration during the initial setting phase. To overcome this, an interesting advancement was introduced High-viscosity glass-ionomer (HVGI), marketed under the trade name of Kids-e-Restore, which is self-adhesive, light-cured, flowable, and ready to use resin-reinforced glass ionomer restorative material. It promotes antimicrobial and anticaries activity by releasing fluoride and its self-adhesive technology eliminates the need for etching and bonding processes with chemical adhesion. Although, one of the most common restorative materials for primary tooth restorations is composite resin, which outperforms GICs in terms of aesthetics, wear resistance, and fracture resistance. Even though, composite resins do not release fluoride and exhibit polymerization shrinkage after setting, which can result in postoperative sensitivity, marginal discoloration, and secondary caries. Therefore, dentists need an alternative to composite or GICs which is affordable, releases fluoride,  simple to use, and has acceptable strength and aesthetics. However, in recent introduction of a novel restorative material, known as Surefil one (Dual-cured composites), which is a self-adhesive fluoride-releasing composite, has been introduced to enable the easy application of bulk-fill composites up to 4-5 mm thick. Additionally, self-adhesive composites have been created by adding acidic moieties to reactive diluents so they will adhere to dentin and enamel. This Dual-cured composites consist of two initiator systems with light-cured and chemical-cured components. The initiator polymerizes top layers and initial hardening with light-cured reaction, while deeper layers are polymerized through a slow chemical-cured reaction. These composites have higher conversion values compared to light-cured bulk-fill and conventional composites, indicating better mechanical properties and degradation resistance. Surefil one  (Dual-cured bulk-fill materials) is used for direct restorations in a posterior-stress-bearing areas, requiring no capping, and different loads. In literature there are no in-vivo studies available comparing the clinical and radiographic efficiency of light cure flowable resin reinforced glass ionomer cement, self-adhesive fluoride-releasing composites and conventional glass ionomer cement in primary molars.